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  • Rautanen, Pauliina Eeva Maria (2021)
    Growth Differentiation Factor-15 (GDF15) is a neurotrophic factor associated with anorexia and weight loss. It is elevated in obesity and various diseases. It signals by forming a tripartite complex with the coreceptor Glial cell line-derived neurotrophic factor (GDNF) family receptor alpha-like (GFRAL) and the receptor Rearranged during transfection (RET). Targeting this pathway has therapeutic potential for the treatment of obesity and anorexia-cachexia syndrome, but many aspects are still unclear. What is the affinity of binding between these proteins? Does GDF15 induce dose- and time-dependent RET phosphorylation and activate intracellular signaling pathways, and are there differences between GDF15 and GDNF signaling, as the different bend angles of their complexes suggest? Can soluble GDF15-GFRAL mediate the effects of GDF15 outside of the brainstem, and what is the function of the short cytoplasmic domain of GFRAL? Furthermore, how well is the pathway evolutionally conserved between species? Binding affinities were assessed with microscale thermophoresis, whereas RET phosphorylation and intracellular signaling assays were performed utilizing immunoprecipitation and western blotting. GFRAL-RET binding is low-affinity (350 nM ± 223) similarly to GFRα1-RET binding (GDNF family receptor alpha-1), whereas GDF15-RET binding without GFRAL does not occur. GDF15 appears to compete for binding to GFRAL or RET, differing from GDNF mechanisms, but noise in the data may have affected the results. The data provide ideas about the ligand-receptor complex formation. Furthermore, RET phosphorylation by GDF15 is dose- and time-dependent. Firstly, the strongest RET and ERK activation occur at GDF15 concentrations typical of disease states. Secondly, RET activation by GDF15 is rapid and sustained like by GDNF activation, whereas ERK activation by GDF15 is rapid and much more transient than by GDNF. Thirdly, AKT activation by GDF15 is much weaker than by GDNF. The differences may be caused by different conformations of binding surfaces for adaptor proteins being available on RET because the bend angles of the complexes are different. Moreover, soluble GDF15-GFRAL does not activate RET, although soluble GDNF-GFRα1 does. Also, the short cytoplasmic domain of GFRAL is not necessary for activating AKT and ERK pathways, but may be needed to activate RET. Furthermore, GDF15 from cynomolgus monkey, but not rat or mouse, activates RET with human GFRAL, indicating sequence similarity in the active site of GDF15. In conclusion, novel aspects of GDF15 signaling and differences between GDF15 and GDNF signaling were discovered.
  • Mehta, Saumya (2020)
    Type 2 diabetes mellitus (T2DM) has been shown to be associated with hyperglycemia, insulin resistance, hyperinsulinemia and impaired insulin secretion from pancreatic β-cells leading to micro- and macro-vascular complications including multiorgan failures. At the cellular level, the mechanism of insulin resistance is associated with complex PI3K-Akt mediated insulin signaling pathway. Moreover, lipid phosphatase SHIP2 (Src homology 2 domain containing inositol 5-phosphatase 2) plays a vital role as a negative regulator of the insulin signaling pathway downstream of PI3K by hydrolyzing phosphatidylinositol- 3,4,5-trisphosphate (PIP3) into phosphatidylinositol- 3,4- biphosphate (PIP2). Scientific reports have shown that inhibition of SHIP2 activity might improve Akt phosphorylation and thus PI3K-Akt mediated insulin signaling pathway. Considering this, I am interested in the SHIP2 inhibitors with drug like properties such as improved solubility, pharmacokinetic and bioavailability properties with little to no contraindications. In the present thesis, I have attempted to detect indirectly the capacity of 8 novel small molecule SHIP2 inhibitors, #160, #161, #162, #163, #167B, #170A, #171, #172 for their ability to phosphorylate Akt kinase in L6 myotubes using immunoblotting as a tool and compared data using graphical representation to pick up the best candidate. Two inhibitors, #163 and #170A were further chosen for alamarBlue® cytotoxicity assay. Treatment with #163 did not display direct cytotoxic effects on the myotubes. The viability of myotubes was not affected at low concentrations of #170A, but it started to reduce at concentrations >200 µM. In my study, I came up with #163 and #170A as the best lead candidates for further analysis. In future, more trials need to be performed with these inhibitors. Moreover, there are several other novel small molecule SHIP2 inhibitors identified from chemical library that need to be tested. Briefly, in this thesis, I have first time reported 8 novel small molecule SHIP2 inhibitors which could be a significant step in the discovery of new T2DM drugs for more efficient, cost effective and safe treatment of the disease with least contraindications.
  • Salumäe, Astrid (2020)
    In biotechnological protein production and metabolic engineering, regulating the expression of genes is essential. For this, expression systems composed of promoters, terminators and transcription factors are essential. So far, majority of these systems use native promoters and transcription factors. That however rises two problems: 1) these systems usually work in only a set of closely related species, 2) native regulatory components can cause unintended expression levels due to the complexity of cellular regulation. Recently, a synthetic expression system (SES) was established for a wide range of fungal species. The transcription factor used in this system comprises an activation domain that originates from a virus. However, in the field of biotechnology and especially food industry, viral DNA constructs are not favorable because of customer concerns. In this paper, plant-derived activation domains were screened in Trichoderma reesei and Pichia pastoris using mCherry as a target gene for measuring the expression levels. The best expression systems were also tested for protein production in T. reesei and P. pastoris. We tested the production of two different proteins – a bacterial xylanase and a phytase. Two of the novel activation domains provided similar expression levels to the viral activation domain in both fungi. In addition, we developed optimized expression systems for an unconventional yeast from Zygosaccharomyces spp. using the novel transcription factors. The best SES version was used for secretion signal sequence screening for xylanase protein production. To further improve the use of T. reesei as a production host, the CRISPR-Cas9 system with the Cas9 D10A nickase version was tested for transformation of T. reesei. Here, we demonstrated the genomic integration and expression of Cas9 D10A nickase in T. reesei using the SES system with the novel plant-derived activation domain. Furthermore, we successfully transformed the T. reesei Cas9 D10A nickase expressing strain using only guide-RNAs and a donor DNA.
  • Ilona, Kortelahti (2024)
    Nuclei isolation is a method used e.g. as a part of chromatin structure research. DNA structure can be examined in its 3D form from isolated nuclei because DNA is still wrapped around the histone proteins. Examining the chromatin structure can offer information e.g. about gene expression and how it is regulated. Isolating nuclei from plant cells demand more optimization compared to animal cells because of the cell wall, chloroplasts and secondary metabolites. The presence of organellar DNA can hamper the later DNA analysis. Secondary metabolites can hinder the actual isolation process. Finding the suitable isolation protocol for species of interest may need careful optimization of different aspects. Different species can differ from each other based on the structural and biochemical characteristics and because of this the same protocol may not ensure as good results for them. Different tissue types of the same species may have also differences in their biochemical and structural characteristics. In this thesis work, three different isolation protocols were used for three plant species; Pinus sylvestris, Betula pendula and Arabidopsis thaliana. The purpose of the work was to compare the results from each nuclei isolation protocol. Optimization of isolation protocol for P. sylvestris and B. pendula would help the isolation process for later research. Thesis work was done to get guidance for this optimization. Samples handled with different protocols were different from each other based on the sample concentration (particles/mL) and the average size of isolated particles. Chloroplast contamination was tested with chloroplast specific primers with PCR. None of the samples were free from chloroplasts.
  • Heikkinen, Aino (2018)
    Chronic psychosocial stress is a major risk factor for anxiety disorders, but the molecular background is still poorly known. Chronic social defeat stress (CSDS) is a mouse model simulating the psychosocial stress that humans face in their life. In CSDS, the examined mice are confronted by an aggressor mouse daily for 10 days, leading to defeat behavior and predisposing to anxiety-like symptoms. Some individuals develop these symptoms (susceptible) whereas others do not (resilient). Chronic stress has been shown to alter myelin-related gene transcription and myelin microstructure. Myelin is a membranous component around axons increasing the velocity of action potentials, and it is produced by oligodendrocytes (OLs). In this study, I investigated if CSDS affects the number of OLs or the size of the myelinated area (estimating the amount of myelin) in two inbred mouse strains that differ in their innate level of anxiety: the non-anxious C57BL/6NCrl (B6) and anxious DBA/2NCrl (D2). I studied three brain regions previously associated with anxiety: the medial prefrontal cortex (mPFC), bed nucleus of stria terminalis (BNST) and ventral hippocampus (vHP). The mice used in this study were previously exposed to CSDS and divided into resilient or susceptible phenotypes, and their brains were collected together with control mice. I performed two immunohistochemical staining experiments to calculate the number of OLs and to measure the myelinated area. I used anti-CNPase for OL cell counts and BlackGold II to stain myelin. I manually calculated the number of OLs using CNPase and cell morphology as markers. I built a macro to measure the BlackGold II stained myelinated area. I also measured the thickness of the corpus callosum (CC, major white matter tract) using the CNPase stained images to examine if the thickness is affected by CSDS. I observed a strain and region-specific effect of chronic stress in the BNST; B6 resilient mice had more OLs than susceptible mice whereas no differences were seen in the D2 strain, or other B6 brain regions. The size of the myelinated area did not differ between the phenotypes in either strain. Moreover, there was no significant correlation between the myelinated area and OL cell number. The CC thickness did not differ between the phenotypes. My findings indicate that myelin and OLs are affected by stress in a region specific manner and possibly contribute to the stress-resilient behavior. The response is genetic background-dependent, as I saw differences in B6 mice but not in D2 mice. Because CC thickness did not differ between the phenotypes, we suggest that CSDS does not induce extensive white matter atrophy in the mice brain. The mechanism underlying this dynamic myelin plasticity during stress requires more investigation, but this study provides evidence that alterations in OLs associate with chronic stress.
  • Pöyhönen, Outi (2001)
    Suomen merialueella esiintyvien harmaahylkeen (Halichoerus grypus) ja norpan (Phoca hispida botnica) ravinnosta on vähän julkaistua tietoa. Tehdyt ruotsalaiset ravintotutkimukset ovat keskittyneet varsinaiselle Itämerelle ja Pohjanlahdelle sekä venäläiset tutkimukset Suomenlahdelle. Nämä tutkimukset eivät kuitenkaan koske varsinaisesti Suomen merialueita. Tämän työn tarkoituksena oli selvittää nuorten harmaahylkeiden ja norppien ravintoa Suomen merialueilla Suomenlahdella, Lounaissaaristossa sekä Merenkurkussa ja Perämerellä. Tarkastelin lajien, sukupuolten ja merialueiden välisiä eroja ravinnossa. Tietoa hylkeiden ravinnosta tarvitaan ennen kaikkea selvitettäessä hylkeiden merkitystä Itämeren kalakantojen hyödyntäjänä. Samalla saadaan taustatietoa hylkeiden aiheuttamien kalastusvahinkojen arvioimiseksi. Suojelun kannalta on tärkeää tietää esimerkiksi, ryöväävätkö nuoret hylkeet kalanpyydyksiä vai takertuvatko ja menehtyvätkö ne niihin sattumalta. Käytössäni oli osa Riista- ja kalatalouden tutkimuslaitoksen keräämää, pakastettua hylkeiden ruoansulatuskanava-aineistoa vuosilta 1986-1999. Se käsitti alle kolmevuotiaina kalanpyydyksiin kuolleita hylkeitä, yhteensä 150 harmaahyljettä ja 62 norppaa, jotka kaikki oli todettu hyväkuntoisiksi. Etsin näiden yksilöiden mahalaukuista ja suolistoista ensisijaisesti kalojen muodoltaan lajityypilliset tasapainokivet eli otoliitit, jotka kulkeutuvat tunnistettavina koko ruoansulatuskanavan läpi. Tulokset osoittivat, että suoliston sisällön analysoinnin mukaanottaminen yleisesti käytetyn maha-analyysin lisäksi kannattaa, koska sen avulla saadaan lisätietoa käytetystä ravinnosta. Sukupuolten välillä ei havaittu tilastollisesti (x2) merkitseviä eroja ravinnossa tärkeimpien kalalajien osalta. Siksi eri sukupuolten aineistot yhdistettiin. Tarkastelutapana käytin suhteellisia frekvenssejä ja esiintymisfrekvenssejä. Harmaahylkeen ravintoa voitiin tarkastella merialueittain, mutta norpan ravintoa aineiston pienuuden vuoksi vain Suomenlahden osalta. Silakka oli suosituin kalalaji molemmilla hyljelajeilla. Ravinto käsitti silakan lisäksi pääasiassa pieniä parvi- ja pohjakaloja, kuten esimerkiksi kuoretta (Osmerus eperlanus) ja kivinilkkaa (Zoarces viviparus). Norpan ravinnossa korostui lisäksi voimakkaasti kolmipiikin osuus; ainoastaan tämän saaliskalan osuudessa hyljelajien välillä oli tilastollisesti merkitsevä ero (x2 p < 0,001). Harmaahylkeen ravinto koostui eri merialueilla pääasiassa samoista lajeista, mutta lajisuhteet vaihtelivat merialueiden ominaispiirteistä johtuen. Ravintovalikoiman laajuutta ja tasaisuutta tutkin Shannonin entropialla (H', J'). Ravinnon vaihtelu harmaahylkeellä oli hieman suurempaa kuin norpalla (H'= 2,065, H'= 1,964), mutta ei aivan yhtä tasaisesti jakautunutta (J'= 0,729, J'= 0,766). Tarkastelin lisäksi aineistoa pyydyskohtaisesti Suomenlahdella ja Lounaissaaristossa lohipyydysten ja muiden pyydysten osalta sekä Merenkurkussa ja Perämerellä silakkapyydysten ja muiden pyydysten osalta, jotta nähtäisiin onko hylje syönyt kyseisen pyydyksen kalaa. Merenkurkun ja Perämeren aineisto viittasi siihen, että hylkeet ovat voineet olla ennen kuolinhetkeään syömässä silakkapyydyksistä. Päätulos kuitenkin osoitti, että alle vuoden ikäisten hylkeiden ravinnossa ei esiintynyt taimenta eikä lohta. Lohipyydystarkasteluhavainnot osoittavat myös, että nuoret hylkeet eivät olleet kuolinhetkellään syömässä kaloja lohiverkoista. Ne ovat mitä ilmeisemmin törmänneet ja hukkuneet niihin pyydystäessään pieniä parvi- ja pohjakaloja, mikä on nuorten hylkeiden suojelun kannalta erittäin tärkeä havainto. Tämä työ on osa laajempaa julkaistavaa tutkimusta, jossa tarkastellaan myös yli kolmevuotiaiden yksilöiden ravintoa.
  • Kaipainen, Sofia (2021)
    Vuorovaikutus luonnonympäristöjen kanssa tukee ihmisen hyvinvointia ja vaikuttaa moninaisin mekanismein hyvinvoinnin eri osa-alueisiin. Kaupungistumisen ja modernisaation tuomat elämäntapojen muutokset ovat herättäneet huolta nuorten sukupolvien luontoyhteyden heikentymisestä, kun yhä harvemmat ihmiset viettävät päivittäin aikaa luonnossa. Nuorten luontosuhde on muihin ikäryhmiin verrattuna erityinen, sillä kiinnostus luonnonympäristöjä kohtaan on usein vähäisempää teini-ikäisenä kuin lapsena tai aikuisena. Luontokontakteilla on vaikutusta nuorten hyvinvointiin sekä mielenterveyteen, mutta kattavaa tutkimusta suomalaisten nuorten luonnossa virkistäytymisen tavoista ei ole aiemmin julkaistu. Tässä tutkielmassa tarkastellaan, miten nuoret kaupunkilaiset virkistäytyvät luonnossa, ja kuinka vuorovaikutus luonnon kanssa vaikuttaa nuorten koettuun hyvinvointiin. Tutkielma on toteutettu osana monitieteistä Luonnon virkistyskäytön terveys- ja hyvinvointivaikutukset - tutkimus kaupunkilaisnuorista (NATUREWELL) -projektia. Aineisto (N=1123) on kerätty syksyllä 2020 Lahden yläkouluissa. Nuorten luonnossa viettämää aikaa, luontoharrastuksia, luontosuhdetta ja heidän kokemuksiaan luonnon hyvinvointivaikutuksista analysoidaan kuvailevin kvantitatiivisin menetelmin. Tulosten perusteella huoli nuorten sukupolvien luonnosta vieraantumisesta ja luontosuhteen katkeamisesta näyttää Lahdessa enimmäkseen perusteettomalta. Suurin osa nuorista viettää viikoittain aikaa luonnonympäristöissä sekä kesä- että talviaikaan, ja erityisesti kodin lähiympäristön luontoalueet ovat nuorille merkityksellisiä. Tytöt viettävät aikaa luonnossa hiukan poikia useammin ja sukupuolten välillä on eroja luontoharrastuksissa. Myös sosioekonomisilla tekijöillä on selvästi yhteys nuorten luonnossa viettämään aikaan. Kiinnostus luontoa kohtaan vaikuttaa laskevan hiukan yläkoulun aikana, ja nuorten luontosuhteessa on havaittavissa polarisoitumista. Pieni osa nuorista ei juurikaan liiku luonnonympäristöissä tai koe yhteyttä luontoon. Valtaosa arvioi hyvinvointinsa kasvavan luonnonympäristössä käydessä, sekä kokevansa usein positiivisia ja harvoin negatiivisia tunteita luonnossa ollessaan. Tutkimus osoittaa, että luontokontakteilla on positiivista vaikutusta nuorten koettuun hyvinvointiin, mutta vaikutuksen voimakkuutta ei voida suoraan arvioida. Pienetkin hyödyt voivat joka tapauksessa olla yhteiskunnallisesti merkittäviä, jos niillä voidaan auttaa nuoria suhteellisen pienillä toimilla. Nuorten luontosuhteen polarisoitumiseen ja sosioekonomisten ryhmien välisiin eroihin luontosuhteessa voidaan puuttua poliittisin keinoin. Luonnonympäristöjen hyvinvointivaikutusten huomioiminen nuorten kannalta esimerkiksi kouluympäristöissä ja kaupunkipolitiikassa voivat olla merkittäviä keinoja nuorten kokonaisvaltaisen hyvinvoinnin lisäämisessä.
  • Mercier, Léon (2018)
    PURPOSE AND GOALS Microalgae are unicellular eukaryotic organisms capable of photosynthesis. They harvest sunlight and efficiently take up carbon dioxide and nutrients such as nitrogen and phosphorus from their environment and use them for their growth. Due to these properties, their rapid growth and ability to survive in a variety of environments, microalgae have potential in biotechnological applications that promote nutrient recovery and recycling, water purification and the carbon neutral production of biochemicals and possibly biofuels. The purpose of this study was to investigate the suitability of a side stream water originating from the production of baker’s yeast (yeastwater) for the cultivation of a species of microalga called Euglena gracilis. The study aimed to determine the capacity of this water to support growth and protein production of E. gracilis as well as the capacity of E. gracilis to remove nutrients from the water. The effect of filtration of the water on these parameters was also studied. Yeastwater contains an organic molecule called betaine in relatively high concentrations. Betaine has previously been shown to boost the production of the important vitamin cobalamin in bacteria. The study aimed to determine the effect of betaine on the growth of E. gracilis and on the production of cobalamin in the algal-bacterial symbiosis. METHODS E. gracilis was cultured in laboratory scale photobioreactors. Its growth, protein production and nutrient uptake capacity was determined. Baker’s yeast production side stream water diluted with MQ-water was used as the growth medium either in filtered or unfiltered form. A control treatment was prepared where no microalgal inoculate was added to the photobioreactor. The same microalga was also grown in a synthetic nutrient medium with and without betaine. The uptake of betaine and biomass concentrations of cobalamin were determined. For the determination of microalgal growth, dry weight determination and flow cytometry analysis were used. Protein production was determined on the basis of total nitrogen concentration in the biomass. Spectrophotometric measuring kits were used for the determination of nutrient concentrations. Liquid chromatography techniques were used for the determination of betaine and cobalamin concentrations. RESULTS Significant microalgal growth was observed in filtered yeastwater, while growth in unfiltered yeastwater was very low. Nitrogen removal was higher in presence of E. gracilis compared to the control treatment. Protein production in yeastwater was comparable to that of microalgae grown in synthetic medium. E. gracilis grew much better in the synthetic media supplemented with betaine than without the addition. Betaine enrichment had no effect on cobalamin production. Cobalamin was produced in unfiltered yeastwater both with and without the presence of E. gracilis. CONCLUSIONS Unfiltered yeastwater does not support growth of E. gracilis possibly due to its high turbidity. Filtered yeastwater, on the other hand can support the production of E. gracilis biomass. E. gracilis can be used to reduce nitrogen concentrations in yeastwater. Yeastwater can support cobalamin production by bacteria, but this phenomenon did not benefit from the presence of the microalga. The effect of betaine on microalgal growth warrants further study to determine whether it is related to the accumulation of intracellular nutrients, storage compounds or to some other phenomenon. Yeastwater is a promising nutrient feedstock for microalgal biomass production. However, the role of filtration and possibility of using other methods for turbidity reduction needs to be further studied.
  • Olkkonen, Emmi (2021)
    Long non-coding RNAs (lncRNAs) are over 200 bp long RNA molecules that are not translated into protein. LncRNAs can regulate the expression of protein coding genes, and studies have indicated their role in stress response. Stress response has also been associated with differences in the structure of the myelin sheaths in the mouse brain cortex. Myelin is produced by mature oligodendrocytes (OLGs), and therefore, OLGs are likely to play a role in stress response. The aim of this thesis was to find lncRNAs differentially expressed in the oligodendrocytes and myelin on the medial prefrontal cortex of stressed mice in comparison to controls. Mice of strains C57/6NCrl and DBA/2NCrl, differing in stress response, were exposed to chronic social defeat stress. After the stress paradigm, the mice were assigned as stress-susceptible or stress-resilient, the susceptible mice exhibiting anxiety-like behavior. RNA from OLGs and myelin from the medial prefrontal cortex of the mice was sequenced, and I compared the lncRNA expression levels between stressed and control mice and stress-susceptible and resilient mice using bioinformatic methods. I also assessed modules formed by lncRNAs and protein coding genes correlating in expression in both datasets. I used RT-qPCR to investigate if results from two differentially expressed lncRNAs, Gm37885 and Neat1, replicate in a stress hormone-treated oligodendrocyte cell line. Three hundred and seventy lncRNAs were differentially expressed between stressed mice and controls or stress-susceptible and resilient mice in the OLG dataset and 132 in the myelin dataset. Two hundred and 87 of them overlapped with a protein coding gene in the OLG and myelin datasets, respectively. Sixty-one percent of the differentially expressed lncRNAs were specific to comparisons in the OLG dataset and 73 % in the myelin dataset, but 39 % of the differentially expressed lncRNAs in the OLG dataset and 27 % in the myelin dataset were shared between them. No module of genes with correlating expression levels was associated with stress, but the expression levels of two correlation modules from each dataset differed between strains. The results for one of the differentially expressed lncRNAs, Gm37885, replicated in stressed Oli-neu cells in RT-qPCR. The results of my thesis indicate that multiple lncRNAs are involved in the mouse stress response, as many were differentially expressed and shared between phenotype comparisons. Additionally, significant gene expression differences were observed between strains, which could contribute to the previously reported strain differences in stress susceptibility. The results also suggest a specific role of Gm37885 in GR-mediated stress response. However, the function of Gm37885 remains unknown, and further studies regarding Gm37885 and the other differentially expressed lncRNAs should be carried out to draw conclusions of their contribution to the OLG-mediated stress response.
  • Ajosenpää, Heikki (2020)
    Maatalousympäristö on muuttunut voimakkaasti ihmistoiminnan vaikutuksesta. Viime vuosikymmeninä on havahduttu monien maatalousympäristönlajien taantumiseen ja uhanalaistumiseen maailmanlaajuisesti. Monimuotoisuus on vähentynyt ja tehostunut maataloustuotanto aiheuttaa monia uhkia peltolinnustolle. Vaikka monia syitä on tunnistettu peltolintujen ahdingon aiheuttajiksi, niin yksittäisten lajien vähenemisen taustalla olevia syitä ei usein tunneta riittävän tarkasti. Elinympäristöjen laadun heikkenemisen ja katoamisen, keinolannoitteiden käytön sekä kasvinsuojeluaineiden tiedetään vähentävän peltolintujen kantoja. Torjunta-aineiden haitallisuus myös muille kuin niiden varsinaisille kohde-eliöille on ollut tiedossa pitkään. Tehoaineista on kehitetty vähemmän myrkyllisiä, mutta niiden kertyminen ja leviäminen pelloilta elinympäristöön ja muihin eliöihin aiheuttaa ongelmia. 1990-luvulla tuhohyönteisten torjuntaan kehitettiin neonikotinoideja, joiden käyttö yleistyi nopeasti maailmanlaajuisesti. Suomessa neonikotinoideja on käytetty pääasiassa siementen käsittelyyn peittaamalla, eli siemenen pinnoittamiseen torjunta-aineella. Neonikotinoidipeittausta on käytetty öljykasveilla ja sokerijuurikkaalla. Ulkomaisissa tutkimuksissa on todettu näiden torjunta-aineiden aiheuttavan haittoja muillekin eliöryhmille kuin torjuttaville tuhohyönteisille. Tuloksia on saatu myös niiden yhteydestä peltolintujen taantumiseen. Suomessa asiaa ei ole tutkittu peltolinnuilla, mutta on todisteita, että neonikotinoideja löytyy linnuista. Linnut ovat hyviä indikaattorilajeja maatalousympäristössä tapahtuville muutoksille. Yksi voimakkaimmin taantuneista lajeista on avoimessa peltomaisemassa ruokaileva ja pesivä peltosirkku Emberiza hortulana. Sen uhanalaisuusluokitus Suomessa on nostettu äärimmäisen uhanalaiseksi, ja sen kanta on pienentynyt myös muualla Euroopassa. Lähitulevaisuudessa sen on ennustettu kuolevan Pohjois-Euroopassa sukupuuttoon, ellei tunnisteta kannankehitykseen vaikuttavia syitä. Tässä tutkimuksessa selvitetään öljykasvien ja sokerijuurikkaan peittauksessa käytettyjen neonikotinoidien yhteyttä peltosirkun kannankehitykseen. Tavoitteena on lisätä tietoa peltolintujen kantoihin vaikuttavista tekijöistä. Aineisto on kerätty peltolintulaskentojen yhteydessä kattavasti peltosirkun esiintymisalueilta eri puolilta Suomea vuosina 2000-2018. Peltosirkkureviirejä havaittiin yhteensä 4430, jotka jaettiin tutkimuksessa neljään maantieteelliseen alueeseen: 1) Pohjanmaa, 2) Etelä-Häme, 3) Lounais-Suomi ja 4) Uusimaa. Paikkatietoaineistossa muodostettiin 277 kpl peltosirkulle ominaista lauluryhmää eli osapopulaatiota, ja tutkittiin lajille tärkeiden elinympäristömuuttujien mahdollisia vaikutuksia lajin reviirimääriin. Elinympäristömuuttujia olivat pienpiirteisten maisemaelementtien määrä (tien-, ojan- ja joenpientareet), viljelykasviryhmien monimuotoisuus, rakennusten määrä, maantieteellinen alue, peltoalan osuus maisematasolla, keväällä kasvipeitteettömän peltoalan osuus sekä edelliskesän lämpötila ja sademäärä. Kiinnostuksen kohteena olivat erityisesti edellisenä kesänä viljeltyjen, neonikotinoideilla peitatuksi olettujen öljykasvien ja sokerijuurikkaan määrät. Näiden tekijöiden vaikutusta peltosirkun reviireihin selvitettiin R-ohjelmiston avulla sovittamalla aineistoon yhdeksän erilaista yleistettyä lineaarista sekamallia. Malleista valittiin neljä parasta, jotka keskiarvoistettiin luonnollisen keskiarvon menetelmällä. Peltosirkun reviirien määrää selittäviksi tekijöiksi saatiin viljelyalan osuus maisemassa, maantieteellinen alue, jokien pituus, lämpötila, vuosi sekä neonikotinoideilla peitattujen kasvien osuus. Mallilla laskettiin ennusteet kolmella eri peitattujen kasvien osuuksilla (matala, keskimääräinen tai korkea) jokaiselle neljälle osa-alueelle. Peitattujen kasvien (öljykasvit ja sokerijuurikas) osuudella ja peltosirkun reviirien määrällä on heikko negatiivinen korrelaatio jokaisella maantieteellisellä osa-alueella. Alueiden reviirimäärät muuttuivat synkronisesti eri peittaustasoilla. Tämän tutkielman tulosten perusteella öljykasvien ja sokerijuurikkaan viljelyllä on heikko yhteys peltosirkun reviirimääriin. Aineiston perusteella ei voi aukottomasti todeta, että syynä olisivat yksinomaan neonikotinoidit. Tiedetään, että ne aiheuttavat peltosirkun kaltaisille lajeille oireita, jotka voisivat selittää huonoa poikastuottoa, tai että yksilöt eivät selviä muuttomatkaltaan. Tulos nostaa esiin saman tärkeän asian, joka on todettu aiemminkin peltosirkun ja monen muun taantuvan lajin kohdalla. Emme tunne lajin käyttäytymistä ja populaatiobiologiaa riittävän hyvin, jotta voisimme nopeilla toimenpiteillä maatalousympäristössä kääntää kannankehityksen suunnan. Peltosirkun pesimämenestykseen liittyviä syitä tulisi tutkia lisää. Torjunta-ainejäämien tutkiminen voisi selittää peltosirkun kohdalla huonoa pesimätulosta. Tällaiselle tutkimukselle olisi tilausta laajemminkin, sillä tietoa kasvinsuojeluaineiden yhteisvaikutuksesta maatalousympäristön eliölajeihin ei ole.
  • Juurinen, Valtteri (2022)
    Opinnäytetyössä tutkittiin olosuhteiden muutosten vaikutusta torjunta-ainepitosuuksiin pilot-mittakaavan sedimenttipylväissä ja suodatinpylväissä. Pilot-mittakaavan pylväissä verrattiin ilmastuksen ja veden virtauksen muutosten vaikutusta pitoisuuksiin. Suodatinpylväissä tarkasteltavina tekijöinä oli orgaanisen aineen ja nollaraudan vaikutus torjunta-ainepitoisuuksiin. Tutkittavina torjunta-aineina olivat atratsiini, simatsiini, heksatsinoni ja diklobeniili, sekä hajoamistuotteet DIA, DEA, DEDIA ja BAM. Kyseisiä torjunta-aineita esiintyy pohjavesissä useissa eri Euroopan maissa mukaan lukien Suomi, vaikka niiden käyttö on lopetettu ja kielletty EU:n alueella useita vuosia sitten. Pylväistä analysoidut ulostulovedet valmisteltiin kaasukromatografia-massaspektrometria (GC-MS) mittausta varten kiinteäfaasiuutolla. Suodatinpylväiden torjunta-aineiden puhdistuskapasiteetti vaihteli testikertojen välillä ja yhdisteet käyttäytyivät eri tavalla suhteessa toisiinsa. Ensimmäisen kuukauden jälkeen talousveden raja-arvo 0,10 µg/l ylittyi heksatsinonin osalta. Toisen kuukauden jälkeen heksatsinonin pitoisuus ylitti jälleen talousveden raja-arvon, niin kuin myös BAM:n. Sitten viimeisellä testikerralla kohonneita yli 0,1 µg/l pitoisuuksia oli atratsiinilla ja heksatsinonilla. BAM:n ja heksatsinonin kulkeutuminen oli odotettavissa yhdisteiden ominaisuuksien perusteella ja niiden hajoaminen on hidasta verrattuna muihin yhdisteisiin. Puolestaan atratsiinin kohonneet pitoisuudet voidaan selittää maaperän kiintoaineksen liikkumisella suodatinpylväästä torjunta-aineiden kanssa. Pelkän hiekan vaikutus suodatinpylväissä aliarvioitiin, mikä vaikutti erityisesti BAM:n ja heksatsinonin pitoisuuksiin.
  • Laakso, Senja (2011)
    In my Master's Thesis I discuss consumption from the perspective of ecological and social sustainability. The environmental space concept is the framework for this study. The environmental space concept was developed in the beginning of the 1990's. It is a space that can be defined with different indicators and within which it is possible to live a decent and socially acceptable life and at the same time consume natural resources in a sustainable way. In this research the upper limit of environmental space is defined as the sustainable level of natural resource use calculated as material footprint and the lower limit as decent minimum reference budgets that illustrate the level of consumption allowing a household to fulfil all basic needs and to participate in society. The material of the study was collected by questionnaires and interviews on the consumption and lifestyle of the participating households. The households interviewed were all single and living on disability pension or basic unemployment allowance. The natural resource consumption of the households was calculated as material footprint. The material footprint is based on the MIPS concept (Material Input per Service Unit) that considers the whole life cycle of products and activities. The participants were also asked to report their income and consumption expenditures. We were also discussing about consumption, the social pressure to consume and use of natural resources. The results show that the low-income households have an average material footprint exceeding the ecologically sustainable level (18 100 kg per year), although the material footprint is lower than average (40 500 kg per year). They also indicate that a sustainable level of resource use cannot be achieved solely by individual choices but the society must improve the changes in the supply of products, services and infrastructure, enabling households to consume in a more sustainable way. The income level of the households remains below the level of the decent minimum reference budgets. The participating households experienced poverty as lack of possibility to consume and recognized the prevailing social pressure to consume. Consuming was characterized by pursuit of status and social comparison between people. The change in prevailing consumer culture is an essential part on the way towards sustainable society, because the amount of consumption grows as long as welfare is measured through consumption. The connection between consumption and natural resource use remained unclear to many of the households and attitudes towards nature alternated between the households. Those households that had been low-income for their whole life, hadn't thought about the sufficiency of natural resources. Their more ecological way of living than average is rather compulsory than their own choice. The rise in their income level would lead to increasing consumption, as households would want to raise their standard of living by moving to a bigger house and travelling. When we notice the limits of the Planet, we should pay more attention to the upper limit of the environmental space to those, who consume the most.
  • Stenberg, Otto (2020)
    Mammalian dentitions exhibit extraordinary diversity in morphology and function. Yet,the mechanisms governing dental development are considered highly conserved across Mammalia. The inhibitory cascade (IC) model is a developmental model explaining variation in molar size proportions observed in mammals. The IC model predicts a range of dental phenotypes based on a dynamic of cumulative inhibition and activation in the sequential development of molars. Whereas most mammals fit these predictions well, bears(Ursidae) are a known exception.Here I employ dental topographic analysis to examine the developmental basis of ursine molar dentitions defying the IC model.I quantified two aspects of tooth shape:molar complexity using orientation patch count (OPC), and tooth size as the area of occlusal surface. As the complexity and size of a tooth mainly emerge based on two different developmental processes –patterning and growth, respectively –these measurements were used to decompose the two phases of tooth development producing the final phenotype. To this end, also an estimate of feature density was calculated.As in previous studies, the molar size proportions of bears were highly incongruent with the IC model. However, complexity along the molar row followed a trend more closely matching the model. Feature density was highest in the third molar. Altogether, these observations suggest an early arrest in the growth of the third molar as the principal cause for bears falling outside the predictions of the IC model –consequently supporting the idea of the inhibitory cascade as a plesiomorphy of Mammalia.As an auxiliary part of this project, I assessed the functionality of Morphoviewer, a new piece of software for measuring complexity. Morphoviewer was successfully applied to infer diet from tooth complexity in a limited sample of carnivorans; and was thus used for all further OPC analyses.
  • Kuure, Senja (2024)
    Vaatetusala on tärkeä hyvinvointia tuottava teollisuudenala. Se on myös hyvin kuormittava ympäristölle. Kiihtyvä kulutus ja vaaralliset työolot ovat osa alan haastetta. Kiertotaloudesta on kaavailtu näihin ongelmiin ratkaisua. Sen tavoitteena on korvata vaatteiden lineaarinen tuotantomalli luonnon kiertokulkuun perustuvalla mallilla sekä mahdollistaa talouskasvun ja luonnonvarojen kulutuksen irtikytkentä lisäämällä samalla hyvinvointia. Kiertotalousprojektia leimaavat heikkoa kestävyyttä peilaavat teknis-taloudelliset ratkaisut eivät yksinään mahdollista riittävää muutosta vaan kulutuskulttuurin haastaminen on välttämätöntä. Tässä tutkielmassa on selvitetty käytäntöteorian keinoin, millaisia kiertotalouteen liittyviä käytäntöjä suomalaisissa pienissä vastuullisissa vaatetusalan yrityksissä toteutetaan. Aineistosta havaittiin kahdeksan eri käytäntöä, jotka liittyivät liiketoiminnan ja tuotannon eri osiin sekä erilaisiin kiertotalouspalveluihin. Kertotalous näyttäytyi vaatetusalalla yritysten näkökulmasta sekä inspiroivana mahdollisuutena että vakavana uhkana yritystoiminnalle. Talouskasvun ja kulutuksen irtikytkennän dilemma oli osoittautunut haastavaksi ratkaista, etenkin innovatiivisen liiketoimintaosaamisen ollessa toistaiseksi yrityksissä puutteellista. Tutkimuskirjallisuuden havaintoja mukaillen kiertotalousliiketoiminta on hyvin haastavaa ja edellyttää vaatetusalalla vallitsevien normien kyseenalaistamista, joka on pienille yrityksille lähes mahdotonta yksin. Muutos voisi mahdollistua, mikäli kuluttajat nousisivat yritysten aktiivisiksi kanssatoimijoiksi, julkisen sektorin tukiessa toimintaa. Toistaiseksi vaatetusala kuitenkin noudattaa perinteistä, lineaarista tuotantomallia ja kiertotalousprojekti sekä sen tavoittelema laajamittainen yhteiskunnallinen muutos on jäämässä utopistiseksi visioksi.
  • Nevanpää, Johanna (2017)
    Different parties such as industry, tourism and research are more and more interested in arctic regions. Tourism is one of the biggest source of livelihood there and growing all the time. Arctic nature is vulnerable and there are indigenous peoples living there. Their way of life is based on natural sources of livelihood such as reindeer breeding. Tourist industry like all the other actions in the region should be socially, economically and environmentally sustainable. So it is important to do research on problems to reconcile different forms of industries and source of livelihoods. The purpose of this thesis is to study possibilities of tourist guidance to solve problems to reconcile reindeer husbandry and tourist industry in municipality of Enontekiö in Finland. It has been noticed in the research of ecotourism that it is possible to influence tourists’ behavior and attitudes by guidance if it is carried out in the right way. This is the reason why my interest is directed to the role of guidance to solve the problems. My research questions are: 1) What kind of problems there are between tourist industry and reindeer husbandry? 2) How is it possible to decrease the harm that tourist industry causes to reindeer husbandry by tourist guidance? 3) How the tourist guidance should be improved? I have done reviews on earlier studies and reports about problems between tourist industry and reindeer husbandry and also about the role of guidance in nature tourism management. Based on these reviews I have proposed a hypothesis how it could be possible to decrease the harm that tourist industry causes to reindeer husbandry by tourist guidance. To test my hypothesis I collected interviews of 15 tourism entrepreneurs and 5 representatives of Metsähallitus. I used the methods of qualitative content analysis to analyze the data. It came out that the biggest problems between tourist industry and reindeer husbandry are disturbance of the peace of pasture, decreasing pasture area, equity in land-use decision-making, and the willingness among the tourism entrepreneurs and reindeer herders to reconcile the source of livelihoods. Tourists do not know much about reindeer husbandry. It is possible to decrease some the harm that tourist industry causes by guidance when it is carried out as recommended in the studies. The role of guidance in decreasing the harms is not very remarkable, because the biggest harms caused by tourist industry are not outcomes of tourists’ thoughtlessness or behavior against rules that could be decreased by guidance. The best education and guidance is given in reindeer farm visits and in guided tours organized by program service companies. The participants of those programs are mainly foreigners even though the majority of tourists in Enontekiö are Finns. Their main source of information is the website of Metsähallitus. The most efficient way to increase tourists’ knowledge would probably be influencing the content of websites of Metsähallitus and marketing of reindeer farm visits and guided tours to Finns.
  • Herranen, Tuulianna (2020)
    Maisterin tutkielma käsittelee uupumuksen yhteyttä oppimisen lähestymistapoihin ja opintomenestykseen. Tutkimus-kohteena ovat bio- ja ympäristötieteellisen tiedekunnan ensimmäisen vuoden opiskelijat vuonna 2018. Tutkimuksen tarkoituksena on hahmottaa uupumuksen, opintomenestyksen ja oppimisen lähestymistapojen välisiä yhteyksiä, sekä muodostaa uupumusprofiileita joiden avulla havaitaan minkälaisia opiskelijoiden joukkoja tiedekunnassamme on. Aineisto on kerätty HowULearn palautejärjestelmän avulla ja tilastolliset testit on tehty SPSS ohjelmalla. Tutkimuksen tuloksena suunnitelmallisella opiskelulla on yhteys hyvään opintomenestykseen, mutta syväsuuntautuneel-la oppimisen lähestymistavalla ei ollut merkitsevää yhteyttä parempaan opintomenestykseen. Pintasuuntautunut op-pimisen lähestymistapa on yhteydessä uupuneisuuteen. Uupumusprofiilit (jotka on toteutettu ANOVA: lla) jakavat vastaajat neljään eri ryhmään. Uupumusprofiilit ovat aiemman tutkimuksen kanssa samankaltaisia, mutta uupuneisuus on bio- ja ympäristötieteellisessä tiedekunnassa yleisempää muihin oppilaitoksiin verrattuna. Uupumusprofiilit eroavat merkitsevästi toisistaan oppimisen lähestymistapojen suhteen. Oppimisympäristö liittyy uupuneisuuteen, sekä oppimisen lähestymistapoihin. Yliopistot, lukiot ja peruskoulut voivat pyrkiä lisäämään opiskelijoiden hyvinvointia suuntaamalla oppimisen lähestymistapoja kohti suunnitelmallisempaa ja syvällisempää oppimista. Pedagogista tutkimusta oppimisen lähestymistapoihin vaikuttamisesta tulisi kuitenkin ensin tehdä enemmän, jotta syy-seuraussuhteet ymmärretään paremmin.
  • Järvinen, Maija (2010)
    The growing interest for sequencing with higher throughput in the last decade has led to the development of new sequencing applications. This thesis concentrates on optimizing DNA library preparation for Illumina Genome Analyzer II sequencer. The library preparation steps that were optimized include fragmentation, PCR purification and quantification. DNA fragmentation was performed with focused sonication in different concentrations and durations. Two column based PCR purification method, gel matrix method and magnetic bead based method were compared. Quantitative PCR and gel electrophoresis in a chip were compared for DNA quantification. The magnetic bead purification was found to be the most efficient and flexible purification method. The fragmentation protocol was changed to produce longer fragments to be compatible with longer sequencing reads. Quantitative PCR correlates better with the cluster number and should thus be considered to be the default quantification method for sequencing. As a result of this study more data have been acquired from sequencing with lower costs and troubleshooting has become easier as qualification steps have been added to the protocol. New sequencing instruments and applications will create a demand for further optimizations in future.
  • Tommila, Jenni (2021)
    Bacteraemia, the presence of bacteria in the bloodstream, may lead to severe and costly health issues. Sepsis, a serious complication of bacteraemia, is one of the top causes of mortality globally. Early and specific diagnostics as well as fast acting are essential in successful treatment. However, current diagnosis relies mainly on time-consuming blood culturing and clinical symptoms, which are unspecific for the causative agent. With the advanced technology and decreasing cost, state-of-art sequencing-based (Next generation sequencing) methods provide a new way to investigate the bacteria present. Metagenomics, which means sequencing and studying all DNA extracted from a microbial community sample, is widely used, but it only describes the genetic potential of a community and does not differentiate live from dead microbes. Metatranscriptomics, in which essentially all RNA from a sample is sequenced, provides information about expression and activity together with identification of viable bacteria, However, the high amounts of host cells and host RNA complicate the detection of bacterial transcripts from complex host-microbe samples. In this thesis, I investigated solutions for the efficient isolation and enrichment of bacterial RNA from whole blood to be used in sequencing and metatranscriptomics analysis. Firstly, I tested the capability of bacterial cell lysis of two commercial blood sampling tubes with Escherichia coli and Staphylococcus epidermidis suspensions. Both tubes, Tempus and RNAgard, were able to lyse gram-negative E. coli cells and good-quality RNA was extracted in measurable quantities with their respective RNA extraction methods. With Tempus tubes the RNA yield was clearly higher. With gram-positive S. epidermidis, RNA quantities from both extractions were below the measurement limits indicating insufficient lysis and need for further optimization. Secondly, I investigated the depletion of polyadenylated (poly-A) transcripts in order to reduce the host transcripts and thus to enrich the bacterial transcripts prior to costly sequencing step. I evaluated the performance of a previously designed in-house protocol, based on the capture of poly-A -transcripts with oligo-dT -beads, and tested different parameters to see whether the depletion efficiency could be enhanced. Most significantly, the amount of oligo-dT -bead suspension was reduced to half from the original protocol. In-house protocols were also compared to a commercial solution, which they clearly outperformed. Depletion performances were tested with a RT-qPCR and dot blot assay, which I designed along this thesis work. Finally, to make the poly-A depletion better suited for blood samples infested with globin transcripts (representing up to 80% of all poly-A transcripts extracted from whole blood), I tested and successfully pipelined the leading commercial method for depleting globin transcripts with the in-house poly-A depletion protocol. The optimized sample preparation protocol provides a platform for further bloodstream infection and sepsis studies. Next steps of the process, such as sequencing and testing with clinical samples, are already ongoing with promising preliminary results. In the future, the metatranscriptomics approach can be utilized in fast and specific identification of the pathogens and their antibiotic susceptibilities. In addition, infection mechanisms and host-pathogen interactions may be studied possibly providing novel insights for sepsis diagnostics and treatment.
  • Talka, Markus (2022)
    Acute leukemia is a life-threatening disease of blood and bone marrow, which is caused by malignant transformation of immature white blood cells. These malignant white blood cells invade space in bone marrow decreasing its ability to produce normal blood cells, eventually leading to death within weeks after the diagnosis without treatment. The acute leukemia can be broadly divided into its lymphoblastic and myeloid form, based on the affected cell lineage. Furthermore, acute leukemias can be classified based on different genomic features, such as gene fusions. Fusion genes are strong drivers in various cancers such as acute leukemias, and they are formed when two or more original genes join together forming a novel hybrid gene. If the novel hybrid gene is transcribed, it can lead to a translation of an abnormal fusion protein with altered function. The detection of the gene fusions is very important, since it affects to diagnosis and treatment of the patient. Various techniques can be used for fusion gene detection, of which the RNA sequencing is the method of choice, due to its ability to provide an unbiased identification of all known and novel gene fusions from the sample in a single experiment. In this thesis, the overarching aim was to develop an optimal sampling protocol for fusion gene detection using RNA sequencing for acute leukemia diagnostics. First, the whole blood samples in EDTA-tubes were collected from acute leukemia patients based on the findings from routine diagnostics. Next, the RNA was extracted at three different timepoints (0h, 8h, and 32h). The samples were stored at 4°C between the extractions. Finally, the RNA sequencing libraries were constructed, and the RNA sequencing was performed. After the sequencing, the data was analyzed using the FusionCatcher algorithm for fusion gene detection and the EdgeR-package for differential expression analysis. The FusionCatcher detected the same gene fusion in all the four fusion gene positive patients compared to routine diagnostics. However, the FusionCatcher failed to recognize the gene fusion in some of the samples with very low number of fusion breakpoint-spanning reads. These reads were visualized with IGV, suggesting that the detection failure resulted from the very low number of break-point-spanning reads. Furthermore, the sample storage did not affect on gene fusion detection. In addition, FusionCatcher detected PIK3AP::BLNK gene fusion from one of the fusion gene negative patients, suggesting a possibility that the patient truly was fusion gene positive. The differential expression analysis revealed changes in gene expression between the different timepoints. The results showed changes in various pathways related for example to cell death and protein biosynthesis, but also to pathways related to cancer. The results showed that prolonged sample storage alters the gene expression profile thus affecting the results of a gene expression study.
  • Iloglu, Zeynep (2024)
    Alzheimer's disease (AD) is a degenerative brain disorder that exhibits deterioration as one gets older. Although much remains to be learned about the pathophysiology of AD, there is strong evidence links amyloid beta (Aβ) plaques, which are responsible for cognitive impairment, to GABAergic interneurons. Model systems are of prime importance for adequately studying the pathophysiology of this disorder; however, existing in vitro models have limitations in producing patient-specific cells. The development of induced pluripotent stem cell (iPSC) technology has provided a novel opportunity for the effective production of disease-relevant cell types while preserving the molecular traits of the patient. In this thesis, the differentiation protocol established by Nicholas et al. (2013) was used to promote the development of interneurons derived from iPSCs. To enhance the efficiency of differentiation, the protocol was modified with the use of small molecules combined in different ways. The end result of the differentiation was characterized using immunocytochemistry (ICC) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The combination of molecules that produced greater efficiency in differentiation was selected, and the optimized protocol was carried out with iPSCs derived from an AD patient harbouring the APP Swedish mutation. The differentiation of cortical interneurons, demonstrated by the expression of pan-neuronal and specific GABAergic neuronal markers, signifies the successful generation of differentiated interneurons in the context of AD. AD iPSCs upregulated several markers related to AD pathology, such as APP and BACE1. However, the cell lines tolerated the small molecules differently, and thus, the protocol needs more optimization in the future. In summary, iPSC-based differentiation protocols are capable of producing disease-specific cell types that would be helpful in developing accurate AD models for revealing the mechanisms of Aβ pathology.