Browsing by department "Department of Biosciences"

In my master's thesis I have studied the characteristics of pedagogically well-designed web-based learning environment, where the contents are presented according to the principles of biology didactics. I have created a website called Virtuaalimetsä (Virtual Forest). Virtuaalimetsä is a web-based learning environment of Finnish forests for the pupils of classes 5 and 6 in primary school. Virtuaalimetsä is made to support both teaching and learning of biology. It offers lots of information and a variety of tools to develop thinking skills. The information of Virtuaalimetsä has its basis in biological research, but the academic nature of this information has been modified to be understandable to children. In this modification the didactics of biology and natural sciences has had a great role. The contents of Virtuaalimetsä fulfill the requirements of National Core Curriculum for Basic Education. With the information from research of blended learning Virtuaalimetsä website has become an effective learning environment. In planning and creating Virtuaalimetsä I had four objectives: 1. Objectives concerning blended learning: to create a good web-based learning environment 2. Objectives concerning learning materials: to increase learners' knowledge and develop their thinking skills, and to create proper tools to achieve this 3. Objectives concerning teaching: to support traditional teaching with a meaningful web-based learning environment 4. Objectives concerning environmental education: to awake a sense of environmental responsibility especially in relation to forests. To achieve these objectives I have studied research about blended learning and didactics of biology. Characteristics of a good web-based learning environment appears to be a proper pedagogical goal, clear research-based information, tools to develop thinking skills, information structuring and intense contemplation, as also logical and pedagogically operational website with good navigation tools. As the leading rules of teaching biology can be mentioned emphasizing the wholeness of nature, system thinking, proper use of concepts, holistic examination of ecological phenomena, using children's previous ideas as a basis for learning and developing observation skills. Virtuaalimetsä has six parts: Metsäkartta (Forest Map), Metsäpolku (Forest Path), Metsäsanasto (Forest Vocabulary), Testaa taitosi (Test your skills), Metsän kasvit (Forest Plants) and Opettajalle (For teacher). This division has been made consistently with the learning tools, and most parts offer a specific way to enhance learning. Virtuaalimetsä is further divided into sub-parts according to different themes: Metsä elinympäristönä (Forest as a habitat), Metsätyypit (Forest types), Metsän kerrokset (Forest layers) and Metsäluonnon monimuotoisuus (Biodiversity in forests). Forest Map concentrates on mind maps and concept maps. These help children to create ideas of wholes and concepts. Concept maps enhance active and meaningful learning and develop learners' meta-cognitive skills. Forest Path has the biological information of Virtuaalimetsä. The information is so presented that learners can get a good picture of forest nature as a whole and as a systemic structure. Information is presented at a concrete level, and new information is continuously connected to the context of forest. Thus the information is kept together, and no single detail is left detached. Many biological concepts are presented, and they help to compose a meaningful image of forests and of the nature of biological phenomena. In Virtuaalimetsä forest environment also gives a familiar ground to examine matter cycle, energy flow and population dynamics. These phenomena represent different kinds of interaction patterns and causal structures in nature, and that is why they improve development of biological thinking and understanding. To awake environmentally responsible attitudes Virtuaalimetsä offers a great deal of necessary information to contemplate environmental problems. Test you skills is a place for exercises. Exercises help in repetition, they give a possibility to test skills and most importantly they activate learned information. Many of the exercises are describing, comparing and classifying exercises, which help to understand the concepts. Exercises that involve explaining help to organize and analyze information. Forest Plants -part has a link to Helsinki University's Pinkka -learning environment. In Pinkka there is a section made especially for Virtuaalimetsä with 30 forest plant species. Plant identification has its own part in Virtuaalimetsä, because knowledge about species has a crucial role in understanding nature and ecosystems. In Forest vocabulary all the concepts presented in Virtuaalimetsä are explained in alphabetical order. In For teachers the idea of Virtuaalimetsä is explained in nutshell. There are also tips for teachers of how to use Virtuaalimetsä in teaching, and how to use information and cognitive tools for example in teamwork, whole class discussions or outside the classroom. The structure of Virtuaalimetsä website has been made into a logical and easily navigated whole by dividing the site according to the different cognitive tools and forest themes. Links are clearly presented, and studying is guided by explaining the contents of each part in advance and by giving tips of how to move in the site. There are also left many possibilities for learners to plan their own course of study. Multiple presentations are present: the information is presented both as pictures and text, and to minimize cognitive load all the information of one subject is presented on the same page.

The purpose of this thesis was to explore the relationships between phytoplankton biomass in lake Pääjärvi and environmental factors. These factors were divided into two categories: external phosphorus loading (total phosphorus, PO4 and organic phosphorus) and thermal conditions (Schmidt stability, heat volume and parent thermocline depth). The data sets at my disposal spanned the years 1994-2010 and contained phytoplankton observations, measurements of lake water temperature and measurements of phosphorus loading from the main rivers and streams flowing into lake Pääjärvi. Heat volume and stability were calculated based on the provided temperature data using a macro for Microsoft Office. The same data were used to calculate parent thermocline depth using LakeAnalyzer. The main statistical analysis performed on these data sets was Redundancy Analysis (RDA) in Canoco for Windows. The data were divided into three different periods: June, July-August and September-October. Each period was examined separately. In addition to total phytoplankton biomass, phytoplankton main groups and selected diatom and flagellate taxa were also examined in relation to the environmental factors. Heat volume proved statistically significant in June in the analysis of total biomass and the main groups and in September-October in the analysis of selected diatom taxa. A statistically significant relationship between PO4 loading and phytoplankton biomass was only detected for Peridinium sp, Rhodomonas lacustris and Mallomonas caudata for July-August. The lack of significance for phosphorus loading in the other contexts may in part be attributed to the distances between the phytoplankton sampling location and the loading measurement sites. The loading would have to drift some time in the lake to traverse these distances before it would come into contact with the measured phytoplankton. During that time, the loading would be susceptible to variations in weather or hydrological conditions as well as susceptible to uptake by other organisms. This may be the reason, or a contributing reason, why phosphorus loading was not significant for most of the contexts explored. However, since phosphorus loading was significant in at least one context, it clearly exerts some influence on the phytoplankton in Pääjärvi. The greater significance for heat volume could be attributed to the cumulative nature of the variable as well as the lack of spatial distance between the temperature sampling distance and phytoplankton sampling location.

Valtaosa maapallon eliölajeista odottaa yhä tieteellistä kuvausta. Perinteisten menetelmien soveltaminen miljoonien nimeämättömien lajien kuvaamiseen on kuitenkin hidasta ja edellyttää enemmän taksonomista työvoimaa, kuin mitä todellisuudessa lienee koskaan saatavilla. Uutena ongelmana morfologisin menetelmin kuvattujen lajien sisältä on yhä enenevässä määrin paljastunut jopa useita piileviä eli kryptisiä lajeja, jotka eroavat merkittävästi muilta kuin ulkoisilta ominaisuuksiltaan. Ratkaisuksi näihin haasteisiin on ehdotettu DNA-taksonomiaa; lyhyiden, vakioitujen DNA-sekvenssien käyttöä uusien lajien tunnistamiseksi ja kryptisten lajien erottamiseksi. Tähän tarkoitukseen soveltuvaksi alueeksi eläimille on osoittautunut osa sytokromi c oksidaasi I (COI) -geeniä. Tutkielmassani tarkastelen DNA-taksonomian soveltuvuutta vastikään kuvatun, ulkoisin tuntomerkein vaikeasti eroteltavan lajiparin Aphodius fimetarius (pihalantiainen) ja Aphodius pedellus (salalantiainen) lajinmääritykseen. Kysyn: Onko näiden kromosomituntomerkein erotettujen lajien tunnistaminen mahdollista COI -geenin sekvenssierojen avulla? Voiko lajit tunnistaa aiemmin esitetyin ulkoisin tuntomerkein? Mikä on tutkimuslajien maailmanlaajuinen levinneisyys? Kumpi lajeista esiintyy Suomessa, ja millainen on tämän lajin geneettinen populaatiorakenne? Selvittääkseni tutkimieni lantakuoriaisyksilöiden lajin käytin kahta geneettistä menetelmää: kromosomipreparaatteja ja COI-geenin sekvenssejä, sekä vähäisiin ulkoisiin tuntomerkkeihin perustuvaa määrityskaavaa. Selvitykseni salalantiaisen esiintymisestä Suomessa perustui kahteen koko maan kattavaan lantakuoriaisaineistoon, sekä itse Etelä- ja Länsi-Suomesta keräämääni aineistoon. Käytössäni oli myös museonäytteitä maailmalta, sekä GenBankissa julkaistuja COIsekvenssejä. COI-sekvensseissä havaitsemani erot jakoivat aineiston kahdeksi toisistaan merkittävästi eroavaksi lajiksi: lajien välillä oli 8,1 % ero emäsjärjestyksessä, mutta lajien sisältä löytyi vain vähän muuntelua (0,2–0,7 %). Sekvenssituntomerkit erottelivat salalantiaisen ja pihalantiaisen samoiksi lajeiksi kuin aiemmin kuvatut kromosomituntomerkit. Määrityskaava sijoitti yli puolet yksilöistä samoihin ryhmiin kuin sekvenssitkin, mutta monilla yksilöillä oli kummankin lajin tuntomerkkejä. Kehittämäni DNA-lajitunnisteet osoittivat, että Suomessa esiintyy tutkituista lajeista vain salalantiainen, ei pihalantiainen. COI-tuntomerkein tunnistin salalantiaisen ensimmäisenä täysin varmana havaintona myös Pohjois-Amerikasta sekä Nepalista. Suomessa tavatuista salalantiaisen 27 COI-haplotyypistä yksi on yleinen ja laajalle levinnyt, muut harvinaisempia jalevinneisyydeltään paikallisia. Suomalaisen haplotyyppiverkoston tähtimäinen muoto viittaa siihen, että salalantiainen olisi vastikään nopeasti levittäytynyt uusille alueille. Kokonaisuudessaan tulokset osoittivat DNA-lajitunnisteet tarkaksi työkaluksi piha- ja salalantiaisen erottelemiseksi. DNA-tuntomerkkien toimivuus perustuu siihen, että lajien välinen sekvenssivaihtelu on merkittävästi lajinsisäistä vaihtelua runsaampaa. Soveltamalla uutta tunnistustyökalua laajaan aineistoon osoitin yhden maamme yleisimmän kovakuoriaisen kuuluvan eri lajiin kuin aiemmin on oletettu, ja tämän lajin olevan maailmalla laajalle levinnyt. Ilman COIsekvenssien tarjoamaa erottelukykyä morfologiset tuntomerkit eivät olisi riittäneet asian selvittämiseen. Tulevaisuudessa olisi kiinnostavaa solveltaa kehittämiäni tuntomerkkejä näiden lajien maailmanlaajuisen levinneisyyden entistä tarkempaan selvittämiseen. Vertailu kotimaiseen museoaineistoon voisi valaista, onko pihalantiainen kuitenkin joskus asuttanut maatamme ja kenties joutunut väistymään nopeasti levittäytyvän sisarlajinsa tieltä. Tähän lajitunnisteet tarjoavat nopean ja varman keinon.

Mitochondrial dysfunction is involved in many neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). Most of the mitochondrial disorders lack effective treatments so far. One of the important defects of mitochondrial dysfunction is the blockade of mitochondrial respiratory chain. An alternative oxidase (AOX), originated from Ciona intestinalis, has been found to counteract this defect by providing a bypath of the mitochondrial respiratory chain in plants, drosophila, mice and human cultured cells. Therefore, we suggest that AOX might be a promising tool for curing neurodegenerative diseases from the aspect of alleviating mitochondrial defects. An engineered mouse model has been created to express the Ciona intestinalis AOX ubiquitously in the whole animal. Our study aims at investigating the expression and function of AOX in the transgenic mouse brain and exploring therapeutic potential of AOX in human diseases. AFG3l2 gene encodes a subunit of m-AAA metalloprotease, which is involved in mitochondrial protein quality control process. Mutations in the AFG3L2 is known to be related to spinocerebellar ataxias 28 (SCA28), a neurodegenerative disease resulting from cerebellar damage. Loss of AFG3L2 gene causes OPA1 protein cleavage and mitochondrial fragmentation which are easily detected. Thus, we propose an in vitro neurodegenerative disease model generated by knocking down of AFG3L2 in target cells. We used western blotting to detect the expression level of AOX in the brain and primary neuro-glia cells of the transgenic mice, finding that the AOX protein reduces in the brain along with age. Antimycin A treatment on neuro-glia cells demonstrated the function of AOX in transgenic pups. However, the respiratory activity caused by AOX also decreases with the mice age. In addition, we constructed a lentiviral vector with DNA recombinant technology to express AOX in U2OS cells. To examine the function of AOX under disease condition, we established an in vitro neurodegenerative disease model by knocking down the AFG3L2 gene of U2OS cells with siRNA, and infected the cells with AOX lentivirus. By comparing the immunostaining images of wild-type and AOX infected cells, we saw a significant difference in the degree of mitochondrial fragmentation between these cells. Nevertheless, the cleavage pattern of OPA1 protein, which is mainly responsible for mitochondrial fragmentation, remains unchanged whether AOX is present in the cell or not. In conclusion, our study first investigated the expression and function of AOX in the brain of this transgenic mouse model. And we established a lentivirus vector to apply AOX gene to human cells, testing the therapeutic function of AOX in a neurodegenerative disease model in vitro. Moreover, the mitochondrial fragmentation of the disease model is alleviated by AOX despite of OPA1 cleavage, indicating that the mitochondrial phenotype caused by loss of AFG3L2 is not only due to OPA1 cleavage, but also related to respiratory defects. This highlights the possibility to rescue the mitochondrial morphological changes from new aspects.

Autophagy is a eukaryotic cellular process where intracellular material is recycled by transporting it in newly formed vesicles to lysosomes for degradation. In normal conditions autophagy supports cellular homeostasis. Different stress conditions can induce autophagy and then it helps the cell to avoid an unnecessary or uncontrolled cell death. RAB proteins are small GTPases that regulate vesicle traffic and fusion events in endocytic and exocytic pathways. RAB24 has recently been shown to participate in autophagy, but there is very little information about how it works at the molecular level. GOSR1 is a Golgi SNARE protein that regulates membrane fusion events, and it has been observed to interact indirectly with RAB24. The participation of GOSR1 in autophagy has not been studied yet. The aim of the study was to find out if RAB24 and GOSR1 colocalize into the same vesicle structures and if they interact within each other. HeLa cells were used as a model organism, and to induce autophagy amino acid starvation was used. For GOSR1 detection a DNA construct was created where GOSR1 was tagged with green fluorescent protein GFP-sequence. Localization was studied with immunofluorescence staining where in addition to RAB24 and GOSR1 also the autophagosomal marker protein LC3 was labeled. The labeled cells were photographed with a confocal microscope. The pictures were analyzed with ImagePro software. Interaction between the proteins was studied using immunoprecipitation. GOSR1 and RAB24 were not observed to colocalize into same structures in significant amount. Instead it was found that GOSR1 colocalized into LC3-positive autophagic vesicles. In immunoprecipitation studies no interaction between RAB24 and GOSR1 could be shown. In order to ensure the results more immunofluorescence stainings should be done using several time points and GFP-tagged GOSR1. Also GOSR1 silencing with siRNA should be used in order to find out if GOSR1 is necessary for autophagy. The immunoprecipitation protocol should be optimized, and the possible interaction could be studied by using other methods, for example yeast-two hybride technology.

Microbiota, the microbial communities living in the gut, skin and glands of vertebrates, is the functional link between a physiological individual and it s surrounding ecosystem. Mutualistic microbes play a role in social systems as well, since they are transmitted through social behaviors and claimed to affect host sociality and behavior. Furthermore, individual stress physiology can affect both behavior and microbiota. I took first steps to reveal the role of gut microbiota in the social dynamics of a group-living cooperative primate, the red-bellied lemur (Eulemur rubriventer). Gut microbiota was affected by seasonal change, stress hormonal profile and pregnancy, and individuals were found to have a strongly group-specific gut microbial composition, highlighting the role of social environment in determining gut microbial composition. Unlike expected, individual sociality was negatively associated with gut microbial diversity. Gut microbiota seems to be largely determined by social factors in this species, indicating that social transmission of beneficial microbiota might have played a role in the evolution of sociality.

Havsekosystemen runt om i världen lider av antropogen inverkan såsom näringsutsläpp och utfiske. Speciellt utfiske av högre trofiska nivåer dvs. stora rovfiskar, anses ha ändrat dynamiken i flera näringsvävar. Ändringarna har lett till kraftiga trofiska kaskader som ökat eller minskat primärproduktionen speciellt vid kustliga vattenområden. Speciellt mesopredatorer har ökat i antal, och i Östersjön är storspiggen (Gasterosteus aculeatus) en art som börjat dominera samhället. Storspiggen konsumerar växtavbetare av trådalger, och kan därmed ha en effekt på trådalgstillväxten i Östersjön. Undersökningens syfte är att granska vilken roll storspiggens predation har i trådalgsbältet, och hur ändringarna syns i näringsväven. Undersökningen bestod av ett mesokosmexperiment och en fältundersökning vid Tvärminne zoologiska station. Mesokosmexperimentet bestod av två behandlingar: 10 mesokosm med två trofinivåer (utan storspigg), och 10 mesokosmer med tre trofinivåer (med storspigg). Trofinivåerna bestod av trådalger (Cladophora sp.), märlkräftor (Gammarus sp.) och storspigg. Experimentet pågick 4 veckor, vartefter mesokosmerna tömdes och innehållet analyserades. Med en veckas mellanrum gjordes fältbesök till den närbelägna ön Långskär, för trådalgsprovtagning, observation av storspiggstäthet och magsäcksanalysering av fångade storspiggar. Trådalgsproverna analyserades under mikroskop. Fältundersökningens resultat visade att mängden storspiggshanar och fångade storspiggar minskade längs med säsongen, medan trådalgsbiomassan ökade. Antalet vuxna storspiggar korrelerade negativt med märlkräftor. Mesokosmexperimentets resultat visade att mesokosmen med storspigg hade i medeltal högre trådalgs-biomassa (24%), högre epifytmängder (72%), färre märlkräftor (79%) och lägre färgintensitet än mesokosmerna utan storspigg. I Mesokosmerna utan storspigg hade trådalgsbiomassan inte ökat nämnvärt, men trådalgen var tydligt grönare i färg och saknade epifyter. Av resultaten framgår att storspiggen påverkar primärproduktionen i ekosystemet, genom en trofisk kaskad, då växtavbetarna regleras kraftigt. Primärproduktionen ökar mest i form av epifyter och mikroalger, vilket leder till att trådalgen kvävs och börjar föråldras. Trådalgen och växtavbetarna har därmed ett mutualistiskt förhållande. För att minska mängden skadliga algblomningar i Östersjön, borde näringsvävarnas stabilitet och mångfald tas i beaktande vid fiskeriförvaltningen för att effektivera Östersjöns rehabilitering.

The purpose of this master's thesis is to study nature values within the Finnish national Natura 2000 network on state owned land. The six goals of this work were achieved: 1) Areas with most nature values were identified by prioritizing habitats of Natura 2000 directive (92/43/EU) within. Areas with high nature value were usually in very natural state and had good connectivity to other similar places, or they were spots of some very rare nature types. 2) It was found out that data used was suitable for identifying conservation values, 3) find out the suitability of Zonation software in conservation area management and maintenance planning and 4) find out how results will change if conservation status is taken into account. As an addition to these 5) the most considerable areas with high conservation value were identified and 6) "Zonation software in a nutshell" was produced in Finnish to assist Finnish state officials to use the software for conservation purposes. These results will help Metsähallitus (The Finnish Forest and Park Service) - Natural Heritage Service - to target resourcing of habitat management and restoration in and around the areas with most considerable nature values. It is essential to sustain these areas and their values so that their nationwide importance can be maintained into the future. Data used in this study covered areas that were classified as Natura 2000 habitats according to European Union Council Directive 92/43/EEC. Analyses were done by using Zonation software, a tool for spatial conservation prioritization. Data consisted of 68 Natura 2000 habitat types and their state of naturalness and representativeness. Zonation took into account the rarity, quality, importance, threat status, biodiversity value, congruity and connectivity of these habitat types. As a result software produces a map of conservation priorities and associated quantitative information, which facilitate identification of areas with most considerable nature values. These were identified both ocularly and with Zonation software. Analyses were done at two levels: all habitat types together and in subgroups following division to major habitat types, such as coastal environments, inland waters, meadows, alpine habitats, peat lands, rocky areas and forests. Results showed that connectivity increased aggregation of areas with high nature values and weighting spread them. Hierarchical analysis was used to find out how nature values changed when the conservation status of the areas were taken into account. The results of hierarchical analysis show that conservation status changed the results a lot. Difference between main analysis and hierarchical analysis was much greater than when taken into account connectivity of feature weights. Hierarchical comparison revealed that many areas with considerable high nature values areas are not presently strictly protected.

The non-lethal effects of predation, i.e. predation risk, can significantly affect the prey population by inducing changes in behavior to reduce the risk of predation. Vigilance, hiding, and fleeing are common responses in order to lower predation risk while changes in habitat selection, habitat use, and changes in activity patterns are more severe changes and can profoundly affect prey fitness. Prey may begin to avoid habitats frequented by predators and may begin to reduce their activity during the time of day when predators are active. Human disturbance can be comparable to predation risk as it may induce similar changes in behavior. Therefore, human activity can be compared to predation risk even though the risk posed by humans may rarely be lethal. For many large vertebrates, however, humans do pose a direct and lethal threat. This is especially true for large predators whose severe decline has been attributed to centuries of persecution and habitat loss and whose populations have only recently began to increase following more favourable management plans and conservation efforts. Similarly, brown bear (Ursus arctos) populations have only recently began to increase in many parts of Europe and North America. In Finland brown bears survived extinction only in the wilderness areas in the north and in the east but have recolonized much of the country in the past decades. These solitary, opportunistic omnivores prefer forested habitats and usually try to avoid humans who they may view as predators. The limited availability of ideal habitats and extensive human activity means that bears may have to use spatio-temporal avoidance of humans rather than large scale spatial avoidance in order to reduce the risk of encountering humans. This should be evident in bear daybed selection whereby bears should select daybed sites away from human activity and select sites that provide good cover against humans while the bear rests during the day i.e. peak period of human activity. Additionally the daybed concealment should be higher closer to human activity. I studied bear daybed selection using GPS location data from collared bears from Central Finland and North Karelia regions and identifying possible daybed sites. Habitat of the daybeds was studied both by visiting daybeds in the field to assess the tree height, tree species composition, and concealment (visibility and canopy cover) and by using GIS software to identify large scale habitat preference. Effects of human activity (house, small roads, large roads) were studied by comparing the concealment of the daybed to a nearby random site and by comparing the bears' early morning locations' distance to human activity with subsequent daybed locations. Further tests were performed to test if season, bear sex, or the study area affected bear daybed selection. The results indicate that bears strongly preferred forested habitats in daybed selection and preferred mixed forests and woodland shrub habitat over the dominant coniferous forests possibly due to their higher proportion and availability of spruce (Picea abies) and deciduous trees (e.g. Betula spp. and Populus tremula) that can offer better cover than pine (Pinus sylvestris) which is dominant in coniferous forests. Mixed forests and woodland shrub may also be preferred as they provide bears with more nutritious vegetation as a food source. Both males and females preferred sites with shorter trees for better concealment while females with cubs preferred sites with taller trees with less concealment. Thus females with cubs may have to trade high concealment for better escape chances for the cubs to avoid potentially infanticidal males. Human activity was shown to affect daybed selection as daybed sites were more concealed than nearby random sites and bears were also closer to human activity during early morning but selected their daybeds farther away. Daybeds were considerably farther away from houses and large roads than from small roads which were often scarcely used forestry roads. Concealment did not change with distance to human activity indicating that bears may not be able to avoid human activity at a large spatial scale even in areas of low human population density. Due to low sample sizes and individual bias the results of this study should be considered more indicative than of high probability. Nevertheless they provide largely new information on bear daybed selection that may be of public interest in reducing human bear conflicts and of use in bear conservation and management.

Host factors play crucial roles in virus infections. Viruses exploit various cellular processes and are counteracted by an arsenal of host antiviral defenses. Characterization of these interactions is crucial for understanding the viral life cycle and developing novel antiviral treatments. Semliki Forest virus (SFV) is a positive-strand RNA alphavirus that has been used as a model virus for multiple clinically significant diseases such as lethal encephalitis. The aim of this thesis was to identify host factors that affect SFV infection to better understand the biology of SFV, and to provide candidate targets for therapies against more serious alphavirus infections. Here I have conducted follow up studies on a previously performed genome-wide siRNA screen that hinted that a number of genes have novel functions in SFV infection. I used an automated high-throughput imaging-based approach to confirm the roles of these host factors in SFV infection. For comparison, I also used a similar strategy to test if these genes affect negative-strand RNA virus infections, using vesicular stomatitis virus (VSV). Additionally, I studied whether the host factors affecting SFV infections perform their roles in the entry and penetration, or post-penetration steps using a previously developed endocytic bypass assay. I identified the γ-aminobutyric acid (GABA) transporter, SLC6A13, as a potential receptor for SFV. I also describe other novel genes that have roles in SFV or VSV infections. In addition, I show that TNP01, RPL18, ETF1, DMN2, and GNDPA1 promote, and HDAC6 counteracts SFV infection in the entry and membrane penetration steps. Furthermore, I report that in the later stages of the infection DDX54 boosts and EIF2B3, EIF4G1, PHB2, EDF1, DDX47, and DHX57 hinder SFV.