Project description:In this work, we describe the transcriptional profiles of adapted and non-adapted one-month-old Baikal whitefish juveniles after heat shock exposure. Preadapted fish were exposed to a repeated thermal rise of 6 °C above control temperature every 3 days throughout embryonic development. One month after hatching, preadapted and non-adapted larvae were either maintained at control temperatures (12 °C) or exposed to an acute thermal stress (TS) of 12 °C above control temperature. The information on transcriptional profiles will contribute to further understanding of the mechanisms of adaptation of whitefish to the environment.
Project description:The altitude gradient limits the growth and distribution of alpine plants.Alpine plants have developed strategies to survive the extremely cold conditions prevailing at high altitudes; however, the mechanism underlying the evolution of these strategies remains unknown. The alpine plant Potentilla saundersiana is widespread in the Northwestern Tibetan Plateau. In this study, we conducted a comparative proteomics analysis to investigate the dynamic patterns of protein expression of P. saundersiana located at five different altitudes. We detected and functionally characterized 118 differentially expressed proteins. Our study confirmed that increasing levels of antioxidant proteins, and their respective activities, and accumulation of primary metabolites, such as proline and sugar, confer tolerance to the alpine environment in P. saundersiana. Proteins species associated with the epigenetic regulation of DNA stability and post-translational protein degradation were also involved in this process. Furthermore, our results showed that P. saundersiana modulated the root architecture and leaf phenotype to enhance adaptation to alpine environmental stress through mechanisms that involved hormone synthesis and signal transduction, particularly the cross-talk between auxin and strictosidine. Based on these findings, we conclude that P. saundersiana uses multiple strategies to adapt to the high-altitude environment of the Northwestern Tibetan Plateau.
Project description:Using WGBS we investigated blood DNA methylation profiles of Cooinda the Alpine dingo and determined putative regulatory elements (unmethylated regions, UMRs, and lowly methylated regions, LMRs).
Project description:Despite the progress achieved in elucidating the ecological mechanisms of adaptive radiation, there has been little focus on documenting the extent of adaptive differentiation in physiological functions during this process. Moreover, a thorough understanding of the genomic basis underlying phenotypic adaptive divergence is still in its infancy. One important evolutionary process for which causal genetic mechanisms are largely unknown pertains to life-history trade-offs. We analysed patterns of gene transcription in liver tissue of sympatric dwarf and normal whitefish from two natural lakes, as well as from populations reared in controlled environments, using a 16 006-gene cDNA microarray in order to: (i) document the extent of physiological adaptive divergence between sympatric dwarf and normal species pairs, and (ii) explore the molecular mechanisms of differential life history trade-offs between growth and survival potentially involved in their adaptive divergence. In the two natural lakes, 6.45% of significantly transcribed genes showed regulation either in parallel fashion (2.39%) or in different directions (4.06%). Among genes showing parallelism in regulation patterns, we observed a higher proportion of over-expressed genes in dwarf relative to normal whitefish (70.6%). Patterns observed in controlled conditions were also generally congruent with those observed in natural populations. Dwarf whitefish consistently showed significant over-expression of genes potentially associated with survival through enhanced activity (energy metabolism, iron homeostasis, lipid metabolism, detoxification), whereas more genes associated with growth (protein synthesis, cell cycle, cell growth) were generally down-regulated in dwarf relative to normal whitefish. Overall, parallelism in patterns of gene transcription, as well as patterns of interindividual variation across controlled and natural environments, provide strong indirect evidence for the role of selection in the evolution of differential regulation of genes involving a vast array of potentially adaptive physiological processes between dwarf and normal whitefish. Our results also provide a first mechanistic, genomic basis for the observed trade-off in life-history traits distinguishing dwarf and normal whitefish species pairs, wherein enhanced survival via more active swimming, necessary for increased foraging and predator avoidance, engages energetic costs that translate into slower growth rate and reduced fecundity in dwarf relative to normal whitefish.
Project description:Is is a fundamental evolutionary question which coordinated molecular changes underly adaptation generally and thermal adaptation specifically. Here we profiled the proteome of the Planarian glacial relict species Crenobia alpina. We sampled individuals from an alpine spring, acclimated groups of individuals at 8, 11, 14 and 17 °C for one week and determined their proteome. These results give insight into the molecular mechanisms underlying thermal adaptation and acclimation to cold and warm temperatures.