Transcriptional Rearrangements Associated with Thermal Stress and Preadaptation in Baikal Whitefish ().

In this work, we describe the transcriptional profiles of preadapted and non-adapted one-month-old juvenile Baikal whitefish after heat shock exposure. Preadapted fish were exposed to a repeated thermal rise of 6 °C above the control temperature every three days throughout their embryonic development. One month after hatching, preadapted and non-adapted larvae were either kept at control temperatures (12 °C) or exposed to an acute thermal stress (TS) of 12 °C above the control temperature. In response to this acute stress, an increase in HSP gene expression (, , , , and ) and was detected, independent of preadaptation. The expression levels of genes responsible for the response to oxygen levels, growth factors and the immune response, , , , , , , , , and were higher in individuals that had previously undergone adaptation. Genes responsible for the regulation of metabolism, , , , , and , however, increased their activity in non-adapted individuals. This information on transcriptional profiles will contribute to further understanding of the mechanisms of adaptation of whitefish to their environment.