Search results for "Metsä"

Puumala- ja lehmärokkoviruksen vaikutus metsämyyrän (Myodes glareolus) metaboliaan

2012

Taudinaiheuttajat, kuten virukset ovat usein haitallisia isäntälajilleen. Virusinfektiot voivat heikentää mm. isäntälajinsa lisääntymistä ja selviytymistä, vaikka ne eivät aiheuttaisikaan näkyviä oireita isäntälajeilleen. Jyrsijöiden yksi yleisimmistä viruksista on hantaviruksiin kuuluva Puumala-virus, jonka isäntälaji on metsämyyrä (Myodes glareolus). Hantavirukset ovat RNA-viruksia ja ne leviävät tehokkaasti tiheissä myyräkannoissa. Puumala-virus voi levitä metsämyyristä myös ihmisiin hengitysteiden kautta aiheuttaen myyräkuumetta. Puumala-viruksen ohella metsämyyristä on löydetty myös lehmärokkovirusta, joka on DNA-virus. Lehmärokkoviruksen tiedetään vaikuttavan heikentävästi metsämyyrie…

Absence of Sex Differential Plasticity to Light Availability during Seed Maturation in Geranium sylvaticum

2015

Sex-differential plasticity (SDP) hypothesis suggests that since hermaphrodites gain fitness through both pollen and seed production they may have evolved a higher degree of plasticity in their reproductive strategy compared to females which achieve fitness only through seed production. SDP may explain the difference in seed production observed between sexes in gynodioecious species in response to resource (nutrients or water) availability. In harsh environments, hermaphrodites decrease seed production whereas females keep it relatively similar regardless of the environmental conditions. Light availability can be also a limiting resource and thus could theoretically affect differently femal…

Elonkirjo ehtyy : suosituksia luonnon monimuotoisuuden turvaamiseksi

2019

The effects of Borrelia infection on its wintering rodent host

2022

AbstractIn seasonal environments, appropriate adaptations are crucial for organisms to maximize their fitness. For instance, in many species, the immune function has been noticed to decrease during winter, which is assumed to be an adaptation to the season’s limited food availability. Consequences of an infection on the health and survival of the host organism could thus be more severe in winter than in summer. Here, we experimentally investigated the effect of a zoonotic, endemic pathogen, Borrelia afzelii infection on the survival and body condition in its host, the bank vole (Myodes glareolus), during late autumn–early winter under semi-natural field conditions in 11 large outdoor enclos…

Statistical models and inference for spatial point patterns with intensity-dependent marks

2009

Population sex-ratio affecting behavior and physiology of overwintering bank voles (Myodes glareolus)

2016

Many boreal rodents are territorial during the breeding season but during winter become social and aggregate for more energy efficient thermoregulation. Communal winter nesting and social interactions are considered to play an important role for the winter survival of these species, yet the topic is relatively little explored. Females are suggested to be the initiators of winter aggregations and sometimes reported to survive better than males. This could be due to the higher social tolerance observed in overwintering females than males. Hormonal status could also affect winter behavior and survival. For instance, chronic stress can have a negative effect on survival, whereas high gonadal ho…

Exposure to environmental radionuclides associates with tissue-specific impacts on telomerase expression and telomere length

2019

International audience; Telomeres, the protective structures at the ends of chromosomes, can be shortened when individuals are exposed to stress. In some species, the enzyme telomerase is expressed in adult somatic tissues, and potentially protects or lengthens telomeres. Telomeres can be damaged by ionizing radiation and oxidative stress, although the effect of chronic exposure to elevated levels of radiation on telomere maintenance is unknown for natural populations. We quantified telomerase expression and telomere length (TL) in different tissues of the bank vole Myodes glareolus, collected from the Chernobyl Exclusion Zone, an environment heterogeneously contaminated with radionuclides,…

Fibroblasts from bank voles inhabiting Chernobyl have increased resistance against oxidative and DNA stresses

2018

Background Elevated levels of environmental ionizing radiation can be a selective pressure for wildlife by producing reactive oxygen species and DNA damage. However, the underlying molecular mechanisms that are affected are not known. Results We isolated skin fibroblasts from bank voles (Myodes glareolus) inhabiting the Chernobyl nuclear power plant accident site where background radiation levels are about 100 times greater than in uncontaminated areas. After a 10 Gy dose of gamma radiation fibroblasts from Chernobyl animals recovered faster than fibroblasts isolated from bank voles living in uncontaminated control area. The Chernobyl fibroblasts were able to sustain significantly higher do…

Infection Load and Prevalence of Novel Viruses Identified from the Bank Vole Do Not Associate with Exposure to Environmental Radioactivity

2019

Bank voles (Myodes glareolus) are host to many zoonotic viruses. As bank voles inhabiting areas contaminated by radionuclides show signs of immunosuppression, resistance to apoptosis, and elevated DNA repair activity, we predicted an association between virome composition and exposure to radionuclides. To test this hypothesis, we studied the bank vole virome in samples of plasma derived from animals inhabiting areas of Ukraine (contaminated areas surrounding the former nuclear power plant at Chernobyl, and uncontaminated areas close to Kyiv) that differed in level of environmental radiation contamination. We discovered four strains of hepacivirus and four new virus sequences: two adeno-asso…

Susceptibility to infection with Borrelia afzelii and TLR2 polymorphism in a wild reservoir host

2019

AbstractThe study of polymorphic immune genes in host populations is critical for understanding genetic variation in susceptibility to pathogens. Controlled infection experiments are necessary to separate variation in the probability of exposure from genetic variation in susceptibility to infection, but such experiments are rare for wild vertebrate reservoir hosts and their zoonotic pathogens. The bank vole (Myodes glareolus) is an important reservoir host of Borrelia afzelii, a tick-borne spirochete that causes Lyme disease. Bank vole populations are polymorphic for Toll-like receptor 2 (TLR2), an innate immune receptor that recognizes bacterial lipoproteins. To test whether the TLR2 polym…