Дисертації з теми "Myode glareolus"

Afin de mieux prévenir l'émergence des maladies infectieuses, il est important d'étudier et de mieux comprendre les interactions qui régissent entre les différents acteurs (humain, virus, hôtes/réservoirs, environnement) intervenant dans ce processus. Nous nous sommes intéressés à la néphropathie épidémique (NE) et plus particulièrement à sa situation épidémiologique en France où une extension de la distribution géographique des cas humains a pu être observée au cours de ces dernières années. La France propose une situation particulière avec des zones dites endémiques (nombreux cas humains de NE) et des zones dites non-endémiques (peu ou pas de humains). Cependant l'influence de l'ensemble des acteurs impliqués dans ces différences épidémiologiques n'est pas connue. Nous nous sommes ainsi intéressés aux interactions entre l'orthohantavirus Puumala, responsable de cette zoonose, et son réservoir, le campagnol roussâtre et aux processus éco-évolutifs qui pourraient influencer l'épidémiologie de la NE en France. Tout au long des travaux de recherche, nous avons combiné deux approches complémentaires : la première centrée sur la virologie et les infections expérimentales en laboratoire, et la seconde centrée sur l'évolution virale et des techniques de séquençage haut-débit. Nous nous sommes concentrés sur deux régions françaises ayant des patrons épidémiologiques vis-à-vis de la NE contrastés, les Ardennes (zone endémique) et le Loiret (zone non-endémique), où le virus est aussi connu pour circuler dans les populations de rongeurs. Nous avons tout d'abord réalisé une synthèse des études menées sur les expérimentations portant sur les orthohantavirus et leurs réservoirs. Celle-ci nous a permis de reprendre les grandes thématiques de recherches abordées sur ce sujet et d'identifier les limites et perspectives pouvant être menées sur ces couples hôtes-pathogènes. Ensuite nous décrivons comment nous avons réussi à isoler pour la première fois les souches PUUV circulant dans les Ardennes et le Loiret ainsi que leur caractérisation sur des rongeurs de laboratoire. Enfin nous décrivons comment les interactions entre PUUV et son réservoir sauvage affectent des processus éco-évolutifs (réponse sérologique, réplication, diversité virale) qui à leur tour peuvent influencer l'épidémiologie de la NE. En conclusion, cette thèse nous a permis de mettre en évidence l'importance de la variabilité des souches PUUV dans l'épidémiologie de la NE et du rôle que pouvait aussi avoir le réservoir
In order to prevent the emergence of infectious diseases, it is important to study and to better understand the interactions that exist between the different actors (human, virus, hosts/reservoirs, environment) involved in this process. We are interested in nephropathia epidemica (NE) and more particularly in its epidemiological situation in France where an extension of the geographical distribution of human cases has been decribed in recent years. France offers a particular situation with so-called endemic areas (many human cases of NE) and so-called non-endemic areas (few or no humans). However, the full set of actors used in these epidemiological differences is unknown. We are therefore interested in the interactions between the orthohantavirus Puumala, responsible for this zoonosis, and its reservoir, the bank voles, and in the eco-evolutionary processes that could influence the epidemiology of NE in France. Throughout the research work, we combined two complementary approaches: the first focused on virology and experimental infections in the laboratory, and the second focused on viral evolution and high-throughput sequencing techniques. We are focused on two French areas with contrasting NE epidemiological patterns, the Ardennes (endemic area) and Loiret (non-endemic area), where the virus is also known to circulate in rodent populations. We first carried out a synthesis of studies on experiments with orthohantaviruses and their reservoirs. This allowed us to take up the major research themes addressed on this subject and to identify the limits and perspectives that can be considered on these host-pathogen pairs. Then we describe how we succeeded in isolating for the first time the PUUV strains circulating in the Ardennes and the Loiret as well as their characterization on laboratory rodents. Finally, we describe how the interactions between PUUV and its wild reservoir affect eco-evolutionary processes (serological response, replication, viral diversity) which in turn can influence the epidemiology of NE. In conclusion, this thesis allowed us to highlight the importance of the variability of PUUV strains in the epidemiology of NE and the role that the reservoir could also have

Les fluctuations climatiques Quaternaires (<2.5 Ma) offrent un contexte approprié à l'étude de l'impact du changement climatique actuel sur la biodiversité. La dernière glaciation, dont le maximum glaciaire s'est terminé il y a environ 19 000 ans, a ainsi largement participé à la distribution des espèces actuelles. Les derniers milliers d'années constituent donc une période propice à l'étude de la mise en place et du maintien de la biodiversité.L'objectif de ma thèse a été de mieux comprendre comment une espèce de rongeur forestier apparue il y a environ 2 Ma, le campagnol roussâtre (Myodes glareolus), a répondu à ces cycles du Quaternaire. Mon étude s'est basée sur une approche morphométrique de plusieurs caractères impliqués dans la mastication (mandibule et molaires), visant à quantifier la différenciation de forme associée à l'influence de différents facteurs.Des résultats contrastés ont été obtenus selon le caractère considéré, la mandibule montrant une importante variabilité liée aux variations de la structure d'âge des populations. Au contraire, les molaires ont pu être utilisées comme marqueur de la structuration biogéographique du campagnol roussâtre.L'étude dans l'actuel des variations de taille et de forme des molaires et mandibules du campagnol roussâtre Myodes glareolus a nécessité l'intégration de thématiques variées touchant au patrimoine génétique des organismes, à leur développement, aux traits d'histoire de vie, à l'environnement, etc. Ceci a permis de mieux appréhender la complexité des processus conduisant à la grande diversité des patrons de forme observés chez le campagnol roussâtre.

The bank vole (Microtus arvalis) develops glucose intolerance both when kept in captivity and in the wild state. Glucose intolerant bank voles kept in captivity exhibited polydipsia, polyuria, hyperglycemia, hyperinsulinemia, islet autoantibodies and a markedly changed islet structure resembling so–called hydropic degeneration. Islets showing hydropic degeneration have reduced β–cell mass. However, the relative islet size to total pancreas area was not changed. Pancreatic islet isolated from glucose intolerant bank voles had an altered islet function showing signs of being exposed to an increased functional demand on their β–cells. Also, islets from male bank voles seem more affected than the islets from females. Islets isolated from glucose tolerant male bank voles cultured for 5 days at 28 mM glucose did not reveal any change in insulin gene expression or insulin biosynthesis rate. However, islets from female bank voles displayed a glucose concentration dependent response. This suggests that there is gender difference in that, islets of female more easily than islets of males adapt to elevated glucose concentration. Furthermore, islets isolated from glucose tolerant males had reduced insulin gene expression after exposure to proinflammatory cytokines for 48 hrs. This effect seemed to be NO-independent since only a minor elevation of nitrite accumulation in the medium was seen, and the use of iNOS inhibitor could not counteract the cytokine effect. The observed response seen in bank vole islets upon exposure to various glucose concentrations or proinflammatory cytokines is similar to those seen in studies of human islets. The bank vole may therefore represent a novel animal model for the study of diabetes. An unresolved issue is the role of the Ljungan virus which is found in the bank vole colony. Bank voles developing glucose intolerance display features of both human type 1 and type 2 diabetes, where environmental factors seems to play an important role as determinant. Our findings suggest that bank voles bred in the laboratory may develop more of a type 2 diabetes. However, bank voles caught in nature instead may rather develop a type 1 form of the disease.

The Chernobyl nuclear incident resulted in the release of high amounts of radionuclides into the environment. Subsequently the Chernobyl exclusion zone (CEZ) was established to prevent human exposure to radionuclides. An expected consequence of exposure to chronic doses of ionizing radiation (IR) in Chernobyl wildlife is increased DNA damage and oxidative stress via reactive oxygen species (ROS) production. The mitochondrial DNA (mtDNA) is the main source of endogenous ROS production, and when damaged by IR it produces more ROS and a concomitant increase in oxidative damage. The molecular mechanisms for the maintenance of the mtDNA in wildlife inhabiting the CEZ is still poorly understood. This study examined key molecular pathways responsible for mtDNA maintenance in animals (bank voles) inhabiting the CEZ (elevated and low background radiation sites). I quantified the expression of two important genes Polg2 and Sod2 implicated in mtDNA repair, replication and ROS scavenging. My model was bank vole (Myodes glareolus) liver and brain tissues sampled in contaminated areas in the CEZ and from uncontaminated control sites outside the CEZ. I also quantified variation in mtDNA copies (a proxy for numbers of mitochondria) and proportion of damaged mtDNA in bank voles. Finally, I estimated potential rate of mitochondria mutations by quantifying the frequency of heteroplasmy using whole genome sequencing (WGS) data of bank vole muscle tissue from animal from contaminated areas in the CEZ and uncontaminated control sites. There was significant upregulation of Polg2 in the livers of bank voles captured from the CEZ. Sod2 in contrast was significantly downregulated in bank voles from the CEZ. There was a non-significant increase in mtDNA copy number in bank voles inhabiting the CEZ compared to bank voles from control sites. I also observed bank voles in the CEZ contained significantly less damaged mtDNA compared with control individuals. In bank vole brains, neither Polg2 nor Sod2 expression differed among contaminated and uncontaminated sites. There were significantly elevated mitochondria copies in bank voles inhabiting the CEZ. The brain data also revealed bank voles from low radiation sites in the CEZ had significantly more damaged mtDNA compared elevated radiation sites and control areas. I found no association between level of radiation exposure and frequency of heteroplasmy, although there was some temporal differences in heteroplasmy. This result suggests that expression of mtDNA repair gene and synthesis of new genomes is a key adaptive machinery for mtDNA maintenance in response to low dose ionizing radiation. I found evidence of tissue specific differences in mtDNA damage and repair pathways in bank voles inhabiting the CEZ. However, with no increase in heteroplasmy, more studies are needed to demonstrate high mutation rates in contaminated bank voles.

S .J. Helyar; Estimating ecological and population genetic parameters in Myodes glareolus, a mammal with cryptic reproduction and dispersal A central theme in ecology is the determination of the factors that regulate population dynamics. For many years research has focused on systems regulated by predation, competition or resource Iimitatiofl, while the host parasite relationship wa~ considered to be neutral or benign, due to host-parasite co-evolution. However, in recent years there has been increasing recognition that parasites can have a key role in population dynamics, by influencing the key population parameters of reproduction and survival, and therefore having the potential to influence the population's intrinsic rate ofincrease. This study applies population genetics to host parasite ecology in order to determine how the endemic Cowpox virus interacts with and affects the host population processes of reproduction and dispersal in the bank vole (Myodes (= ClelhrionomY$) glareolus, Shreber 1780). This is a particUlarly challenging situation for determining parental relationships, as bank voles exhibit cryptic mating and maternal care, meaning that no information is available from behavioural observations to support the pedigree construction. Therefore a simulated population is first used to determine which software was most appropriate to use. A combination of parentage and sibship analyses is then used to maximise the information obtained on relationship structure. The fine scale population structure is also determined. Two events have been shown to cause variation in the levels of relatedness within a population, philopatry and founder events, and both of these are shown to be occurring in this population. This study demonstrates the occurrence of sex-biased dispersal using genetic techniques, so confirming a behavioural mechanism that is hard to identify via CMR studies due to the postnatal dispersal of this species. I also describe the fine scale population structure, and the seasonal fluctuations in this structure, with higher levels of structure evident during the summer than winter, which are determined by a combination of male biased dispersal and changes in population density. These analyses are then extended to consider how the population .genetics of the bank vole can contribute to our understanding of the bank vole-cowpox system. Two hypothesis are investigated; firstly to determine if there are patterns of infection that can be identified from the host genetics, and secondly to build on previous studies, by determining if the delay in the onset of breeding due to cowpox infection has an effect on the Lifetime Reproductive Success (LRS) of. the host. While no conclusive evidence was found for the transmission pathway, we do show that the delay in the onset of reproduction caused by cowpox infection has a major negative effect on LRS, reducing the number of an infected females' offspring by 30-100% compared to an uninfected female. Importantly, as cowpox prevalence increases with density in this species and populations with a high prevalence of cowpox are predicted to have reduced fecundity, cowpox virus infection therefore may be considerably influencing population dynamics.

Islands are extremely variable habitats, differing in shape, size, degree of isolation, geography and climate. They are often described as ‘natural laboratories’ and have proven beneficial for testing theories on evolution and adaptation. Rodents on islands are often characterised by differences in demography, morphology and behaviour compared to adjacent mainland populations. One of the most notable and extensively reported differences is in body size. Several adaptive theories have been suggested to explain these phenomena, which have been termed ‘island syndrome’, yet few have been empirically tested. The bank vole (Myodes glareolus) is a good model for studying the evolution of island syndrome, being present throughout the British mainland as well as on 13 small offshore islands. Voles on four of these islands exhibit the gigantism characteristic of island syndrome. The aim of this study was to compare insular and mainland populations of voles to determine whether island syndrome is truly an adaptive response to life in insular habitats, or whether it is driven by more random processes such as founder effects and genetic drift. In this thesis, I present data on body size, demography and skull morphology along with phylogenetic analyses based on mitochondrial DNA sequences from island and mainland populations of bank voles around the UK. Whilst I was able to demonstrate insular changes in body size, I was unable to demonstrate any demographic differences consistent with the predictions of island syndrome. Phylogenetic analyses revealed that body size differentiation on islands was not related to phylogeographic history. There was little evidence for a single unifying theory explaining the existence of island syndrome, thus I conclude that this biological pattern is probably caused by multiple environmental and genetic factors.

Space use patterns are driven by the individual's need to acquire enough resources to survive and reproduce. Population dynamics, in turn, are determined by individual survival and reproduction. In rodents, these two key elements to a species' ecology have been investigated for decades, but often data quality is insufficient to address important questions. This thesis aims to improve our understanding of space use patterns and population dynamics in the bank vole (Myodes glareolus) and the wood mouse (Apodemus sylvaticus). I also try to overcome current methodological limitations by using a new method for field data collection and exploring the use of in-silico methods. In chapters 2 and 3, I analyse space use patterns of both species. My results highlight the importance of predation risk and food availability for space use patterns. Chapter 3 also reveals the advantage of using an individual based model to address space use related questions. In chapter 4, I analyse the density dependence of body weight and life history parameters in our wood mice population by constructing an integral projection model. I found mixed results for the density dependence of body weight but proof for changes of generation time and reproductive success at higher densities. Using an individual based model, I show in chapter 5 that sensitivity of space use estimates to low temporal resolution of location fixes varies between different movement types. This thesis shows that space use patterns are driven by interactions of many drivers, including sex, season, food availability and body weight, but are dominated by predation risk. It also supports the importance of population density for space use patterns and population dynamics. Finally, I highlight the potential of using in-silico methods to investigate the ecology of rodents and the current vulnerability of space use estimates to bias.

Le campagnol roussâtre Myodes glareolus est le réservoir principal de l'hantavirus Puumala (PUUV) responsable de la néphropathie épidémique (NE) en Europe. L'objectif de cette thèse est de décrire la variabilité de la résistance / tolérance de M. glareolus à PUUV et d'explorer son rôle dans la distribution et la transmission de ce virus. Nous émettons l'hypothèse que la tolérance à PUUV favorise sa persistance et sa transmission, ce qui devrait accroître le risque d'émergence de la NE. Nous avons développé une approche gène candidat pour déterminer le rôle de trois gènes de l'immunité dans la résistance / tolérance à PUUV. L'existence d'associations positives entre les allèles du gène Drb et l'infection par PUUV d'une part et les relations négatives détectées entre le niveau d'expression du gène Tnf-α et la prévalence en PUUV d'autre part corroborent l'évolution d'une tolérance en zones d'endémie de la NE. Elle pourrait être sélectionnée en réponse au coût de la réponse inflammatoire développée contre PUUV. L'approche de génétique des populations a démontré le rôle de la dynamique des réservoirs dans l'épidémiologie de PUUV. La comparaison du polymorphisme des gènes Drb et Tnf-α et des patrons génétiques neutres semble cependant indiquer une faible influence de la sélection dans le polymorphisme de ces gènes. Ce résultat suggère un effet potentiellement important de la plasticité phénotypique dans les niveaux de résistance/tolérance observés. L'étude de la communauté d'helminthes a confirmé cette hypothèse en révélant l'impact de certaines espèces sur le risque d'infection à PUUV
The bank vole Myodes glareolus is the main reservoir of Puumala hantavirus (PUUV), the agent of nephropathia epidemica (NE) in Europe. This work aims at describing the variability of M. glareolus resistance / tolerance to PUUV and at exploring its role in the distribution and transmission of the virus. We hypothesized that tolerance to PUUV should favour its persistence and transmission, what could increase the risk of NE emergence.We developed a candidate gene approach to determine the role of three immune genes in the resistance / tolerance to PUUV. Both the detection of positive associations between Drb alleles and PUUV infection and the negative relationship observed between Tnf-α gene expression and PUUV prevalence corroborated the evolution of tolerance in NE endemic areas. The costly inflammatory response activated against PUUV infection could mediate this evolution.Using landscape population genetics, we revealed the role of M. glareolus population dynamics in PUUV epidemiology. The comparison of Drb and Tnf-α genetic differentiation with the neutral pattern detected at microsatellites indicated that selection weakly acted on these immune genes. This result suggested the potential effect of phenotypic plasticity in the balance of resistance/tolerance to PUUV. The study of helminth communities confirmed this hypothesis as it revealed the impact of two nematode species on the risk of PUUV infection

Human-induced fragmentation of ecosystems and natural habitats is considered one of the major threats to biodiversity. Albeit a considerable effort have been invested in research, progresses in conservation measures occur too slowly compared to the current rate of extinction of plant and animal species caused by the fragmentation of habitats. The delay is mainly due to the complexity of the processes involved, which produce a multitude of effects, both direct and indirect, occurring at various spatial scales and levels of biological organization. Recently, it has emerged how conservationists would not only need face and find answers to ecological problems, but their analysis would have to take into account also socioeconomic factors , since the latter could threat the success of conservation actions and determine a waste of limited financial resource. In a world with limited conservation funds, and with a great geographical variability in the conservation costs, efficiency would be better measured in terms of conservation return on financial investment. The scope of this study was to determine the fixed-budget optimal conservation strategies in fragmented landscapes for two forest-dwelling rodents hazel dormouse Moscardinus avellanarius and bank vole Myodes glareolus, by analyzing their demographic parameters, and by evaluating the efficacy and cost-effectiveness of simulated conservation actions. From results emerged that the hazel dormouse vital rates showed a strong relationship with the quality of the fragments (i.e. the complexity of the shrub layer), influencing both the survival rate and the fertility. On the other hand, the bank vole appears to be related to suboptimal quality fragments, with survival rates increasing in smaller fragments and fertility increasing in fragments with lower fruit-bearing shrubs density. Likewise, the analysis, which aimed to predict the species persistence in the fragmented landscape, resulted in opposite trends. While the population viability analysis for the hazel dormouse predicted an important decline in metapopulation abundance and occupancy during the 50-year simulated period, the population viability analysis for the bank vole metapopulation showed a marked increase in abundance within the same time interval. The optimization protocol I elaborated explores which fixed-budget conservation actions would enhance the persistence of the hazel dormouse metapopulation. The protocol allowed to determine that, between the two conservation strategies explored, i.e. habitat restoration and habitat quality improvement, to restore a certain amount of woodlands is the most effective way to increase the metapopulation abundance and to reduce, although slightly, the probability of decline of a given percentage. It is important to note that, however, the optimal conservation strategy would not reverse or prevent the hazel dormouse metapopulation negative trends.

Le campagnol roussâtre Myodes glareolus est le réservoir principal de l'hantavirus Puumala (PUUV) responsable de la néphropathie épidémique (NE) en Europe. L'objectif de cette thèse est de décrire la variabilité de la résistance / tolérance de M. glareolus à PUUV et d'explorer son rôle dans la distribution et la transmission de ce virus. Nous émettons l'hypothèse que la tolérance à PUUV favorise sa persistance et sa transmission, ce qui devrait accroître le risque d'émergence de la NE. Nous avons développé une approche gène candidat pour déterminer le rôle de trois gènes de l'immunité dans la résistance / tolérance à PUUV. L'existence d'associations positives entre les allèles du gène Drb et l'infection par PUUV d'une part et les relations négatives détectées entre le niveau d'expression du gène Tnf-α et la prévalence en PUUV d'autre part corroborent l'évolution d'une tolérance en zones d'endémie de la NE. Elle pourrait être sélectionnée en réponse au coût de la réponse inflammatoire développée contre PUUV. L'approche de génétique des populations a démontré le rôle de la dynamique des réservoirs dans l'épidémiologie de PUUV. La comparaison du polymorphisme des gènes Drb et Tnf-α et des patrons génétiques neutres semble cependant indiquer une faible influence de la sélection dans le polymorphisme de ces gènes. Ce résultat suggère un effet potentiellement important de la plasticité phénotypique dans les niveaux de résistance/tolérance observés. L'étude de la communauté d'helminthes a confirmé cette hypothèse en révélant l'impact de certaines espèces sur le risque d'infection à PUUV
The bank vole Myodes glareolus is the main reservoir of Puumala hantavirus (PUUV), the agent of nephropathia epidemica (NE) in Europe. This work aims at describing the variability of M. glareolus resistance / tolerance to PUUV and at exploring its role in the distribution and transmission of the virus. We hypothesized that tolerance to PUUV should favour its persistence and transmission, what could increase the risk of NE emergence.We developed a candidate gene approach to determine the role of three immune genes in the resistance / tolerance to PUUV. Both the detection of positive associations between Drb alleles and PUUV infection and the negative relationship observed between Tnf-α gene expression and PUUV prevalence corroborated the evolution of tolerance in NE endemic areas. The costly inflammatory response activated against PUUV infection could mediate this evolution.Using landscape population genetics, we revealed the role of M. glareolus population dynamics in PUUV epidemiology. The comparison of Drb and Tnf-α genetic differentiation with the neutral pattern detected at microsatellites indicated that selection weakly acted on these immune genes. This result suggested the potential effect of phenotypic plasticity in the balance of resistance/tolerance to PUUV. The study of helminth communities confirmed this hypothesis as it revealed the impact of two nematode species on the risk of PUUV infection

The magnetic orientation was established in several species of rodents, but the mechanism of its perception has not been determined. Aim of this work was to verify magnetic sense in the bank vole (Myodes glareolus) and try to solve the nature of its magnetoreception in tests carried out in total darkness and when the horizontal component was reversed and the vertical component was inverted. A spontaneous directional preference in the magnetic field was tested in circular arena.

Badania przedstawione w niniejszej pracy były finansowane z grantu Narodowego Centrum Nauki, N 304 280840, przyznanego J. R. E. Taylorowi.
W niniejszej rozprawie testowałem hipotezę, że stres oksydacyjny, uwidaczniający się w oksydacyjnych uszkodzeniach tkanek, jest bezpośrednim fizjologicznym kosztem rozrodu. Obiektem badań były samice nornicy rudej Myodes glareolus. W pierwszym eksperymencie samice mogły urodzić jeden lub dwa naturalne mioty. Miałem także osobniki nie rozmnażające się. Oznaczyłem uszkodzenia oksydacyjne lipidów i białek w różnych tkankach. Wbrew oczekiwaniom, uszkodzenia te albo nie różniły się między samicami z grup reprodukcyjnych, albo były niższe u samic rozmnażających się. W drugim eksperymencie różnicowałem więc wysiłek samic poprzez dodawanie dwóch młodych do oryginalnego miotu lub zmniejszałem go do dwóch młodych w kolejnych czterech miotach rodzonych przez samice. Wbrew przewidywaniom uszkodzenia u samic rozmnażających się nie różniły się od uszkodzeń samic nie rozmnażanych lub były od nich niższe. Takie same oznaczenia uszkodzeń oksydacyjnych, wykonałem u samic nornicy bezpośrednio po odłowieniu z naturalnego środowiska, przed i po okresie rozrodu. Ogólnie samice po reprodukcji najczęściej albo się nie różniły pod względem poziomu stresu oksydacyjnego od osobników przed reprodukcją, albo poziom ten był nawet niższy. Podsumowując moje wyniki falsyfikują hipotezę, że stres oksydacyjny jest mechanizmem odpowiedzialnym za powstawanie kompromisów pomiędzy aktualnym inwestowaniem energii w rozród a przeżywalnością i przyszłym sukcesem reprodukcyjnym.
I tested the hypothesis that oxidative stress is the proximate mechanism of reproduction costs, using bank vole Myodes glareolus as a model species. In the first experiment, the oxidative damage to lipids and proteins was measured in breeding females after rearing one and two litters, and in non-breeding females. Surprisingly, the level of oxidative damage did not differ between females from different reproductive treatments or was lower in breeding than in non-breeding females. In the sceond experiment, I experimentally manipulated the reproductive effort of females from selected and control lines by reducing or enlarging the original litter size in four consecutive litters. The level of oxidative damage to tissues in breeding voles did not differ from non-breeding individuals or was even lower. I also measured the level of the same oxidative stress markers in bank vole females from a free-living population. In general, females afterreproduction did not differ in the level of oxidative stress form females before reproduction, and in a few cases the level was even lower. In summary, my results undermine the hypothesis that oxidative stress is the key proximate mechanism underlying the trade-off between the current investment in reproduction and future survival or reproductive success.
Wydział Biologiczno-Chemiczny.

Consistent among-individual differences are found in most areas of biological research, and appear to constrain animals’ plasticity and thus the possibility to adapt optimally to the environment. Recent years have seen increased interest in individual variation in behaviour, cognition and physiology, the proximate causes and the evolutionary mechanisms maintaining this variation. Not only there is reason to believe that individual differences in these domains affect fitness, it is likely that they are inter-related, forming a complex net of interactions regulated by different trade-offs. Empirical testing of recent theoretical framework ─ suggesting possible mechanisms linking behaviour, cognition and physiology ─ provided mixed findings. The aim of this thesis was to investigate whether individual differences in behaviour (animal personality), cognition and physiology are linked, and whether individuals that present different profiles display ecologically-relevant differences that might affect their fitness. To achieve this goal I assessed 86 bank voles (Myodes glareolus) for personality (i.e. activity and boldness), associative learning and reversal learning, as well as foraging and anti-predator strategies. I also evaluated their response to challenges, through measurement of faecal corticosterone metabolites. Main results support the predictions made by authors Carere and Locurto (2011) and Sih and Del Giudice (2012). Voles’ personality and cognitive style were indeed connected, and constrained by a speed-flexibility/accuracy trade-off. Proactive (i.e. bolder and more active) individuals were faster but more rigid learners, whereas reactive individuals (i.e. shyer and less active) proved slower but more flexible. Personality and cognitive style predicted the individual bias in a risk-reward trade-off. Proactive individuals tended to maximise reward at the cost of running higher risks, and reactive individuals favoured safety in spite of increased searching effort. However, body weight changes did not differ between the two groups. The response to a moderate challenge was not correlated with either personality or cognitive style. However, individual profiles predicted individual endocrine state in two relatively undisturbed conditions. Taken together, these result show consistent individual differences in personality, cognition and physiology. Such differences appear inter-related and extend to fitness-relevant traits. These results might help future research in the investigation of the evolutionary maintenance of among-individual variation.

This thesis is a part of the project aimed at sequencing the genome and transcriptome of the bank vole (Clethrionomys glareolus). The role of natural selection in the evolution of mitochondrial DNA (mtDNA) has been subject to much discussion; while some studies did not provide evidence that selection affected the phylogeography of the studied species, other considered adaptive evolution important. The bank vole is the key model we use to study the adaptation to climate change. As with other species, the phylogeography of the bank vole has been based on the variation of a small part of mtDNA. The goal of the thesis was to sequence the entire mitochondrial genome for representatives of all main mtDNA lineages of the bank vole using the Sanger and Illumina technologies, and to assess the role of selection and adaptation in the evolution and phylogeography of this species. The adaptive evolution in mtDNA probably was not the main driving force during the postlacial colonization of Europe. However, signatures of adaptive evolution have been found - an amino acid change with possible functional consequences in one gene and an excess of radical changes in physical- chemical properties of amino acids in populations at the latitudinal (northern and southern) extremes of the bank vole distribution. Key...

Habitat fragmentation during 50s of 20th century caused decrease in food resource availibility for many small mammalian forest species. Despite all of the changes, those species managed to adapt to it - one of the adaptation mechanics has been migrating into agricultural areas. The main aim of this study was to describe the spatial activity of Apodemus sylvaticus and Myodes glaerolus inside two forst patches and compare it. My next aim was evaluate the significance of agricultural areas nearby the researched forest patches. One part of this was even the comparison of different marking techniques used for rodents in field. Data describing movement activity of researched species were collected using capture-mark-recapture (CMR) As expected the data differ - Greater mobility was found in A. sylvaticus, the M. glaerolus preffered to stay inside patches with larger vegetation cover. The raids into surrounding patches differed even in those two researched forest sites. In site "Samota" A. sylvaticus showed greater movement distance, however in "Hejtman" it were M. glaerolus expressing greater movement ability. Theirs movement were directed inside clover field. Both species of Samota site ventured into patches with dense plant cover, perhaps to minimise the risk of predation. The best method of marking proved to be the clipping the rodents ears with tags. As the next more efficient I would choose the ear-clipping.

The dissertation summarises the result of the study of small terrestrial mammals (Eulipotyphla, Rodentia) along natural (watercourses) and anthropogenic (road, highway) landscape barriers. It points to an interesting phenomenon of road drainage ditches as a transitional migration environment, further it assesses the level of locomotion activity, the rate of structure of subpopulations and the frequency of crossing watercourses in the case of selected rodent species. It contributes with its results to solving problems concerning the effect of these landscape structures on the species diversity, ground mobility or genetic structure of small terrestrial mammals. ˙˙˙˙