News News

Human impact has contributed to the decline of the Eurasion lynx

Disentangling the contribution of long?term evolutionary processes and recent anthropogenic impacts to current genetic patterns of wildlife species is key to assessing genetic risks and designing conservation strategies. Eighty whole nuclear genomes and 96 mitogenomes from populations of the Eurasian lynx covering a range of conservation statuses, climatic zones and subspecies across Eurasia were used to infer the demographic history, reconstruct genetic patterns, and discuss the influence of long?term isolation and more recent human?driven changes. Results show that Eurasian lynx populations shared a common history until 100,000 years ago, when Asian and European populations started to diverge and both entered a period of continuous and widespread decline, with western populations, except Kirov (Russia), maintaining lower effective sizes than eastern populations. Population declines and increased isolation in more recent times probably drove the genetic differentiation between geographically and ecologically close westernmost European populations. By contrast, and despite the wide range of habitats covered, populations are quite homogeneous genetically across the Asian range, showing a pattern of isolation by distance and providing little genetic support for the several proposed subspecies. Mitogenomic and nuclear divergences and population declines starting during the Late Pleistocene can be mostly attributed to climatic fluctuations and early human influence, but the widespread and sustained decline since the Holocene is more probably the consequence of anthropogenic impacts which intensified in recent centuries, especially in western Europe. Genetic erosion in isolated European populations and lack of evidence for long?term isolation argue for the restoration of lost population connectivity between European and Asian poulations. informacion[at]ebd.csic.es: Lucena-Perez et al (2020). Genomic patterns in the widespread Eurasian lynx shaped by Late Quaternary climatic fluctuations and anthropogenic impacts. MOL ECOL 29(4) DOI 10.1111/mec.15366


https://onlinelibrary.wiley.com/doi/full/10.1111/mec.15366
Average (0 Votes)

Latest News Latest News

Back

A source of exogenous oxidative stress improves oxidative status and favors pheomelanin synthesis in zebra finches

A source of exogenous oxidative stress improves oxidative status and favors pheomelanin synthesis in zebra finches

Some organisms can modulate gene expression to trigger physiological responses that help adapt to environmental stress. The synthesis of the pigment pheomelanin in melanocytes seems to be one of these responses, as it may contribute to cellular homeostasis. Environmental oxidative stress was experimentally induced in male zebra finches Taeniopygia guttata by the administration of the herbicide diquat dibromide during feather growth to test if the expression of genes involved in pheomelanin synthesis shows epigenetic lability. As pheomelanin synthesis implies decreasing the availability of the main cellular antioxidant (glutathione), it is expected to cause oxidative stress unless a protective mechanism limits pheomelanin synthesis and thus favors the antioxidant capacity. However, diquat exposure did not only improve the antioxidant capacity of birds, but also upregulated the expression of a gene (AGRP) that promotes pheomelanin synthesis in feather melanocytes, leading to the development of darker plumage coloration. No changes in the expression of other genes involved in pheomelanin synthesis (Slc7a11, Slc45a2, MC1R, ASIP and CTNS) were detected. DNA methylation levels only changed in MC1R, suggesting that epigenetic modifications other than changes in methylation may regulate AGRP expression lability. These results suggest that exogenous oxidative stress induced a hormetic response that enhanced their oxidative status and, consequently, promoted pheomelanin-based pigmentation, supporting the idea that birds adjust pheomelanin synthesis to their oxidative stress conditions. información[at]ebd.csic.es: Rodríguez-Martínez & Galván (2019) A source of exogenous oxidative stress improves oxidative status and favors pheomelanin synthesis in zebra finches. Comp Biochem Phys C https://doi.org/10.1016/j.cbpc.2019.108667


https://www.sciencedirect.com/science/article/abs/pii/S1532045619303837