Short tandem repeats (STRs) are considered to be one of the sources of genotypic variation. Mutations in STRs often have substantial phenotypic consequences, ranging from diseases development to useful phenotypic variability. As such, STRs combine characteristics of genetic and epigenetic factors that may facilitate adaptation to environmental changes or evolvability. While many STRs are located within gene deserts and might not play any specific role, some of them can occur within coding sequence or regulatory regions of genes, significantly modulating their function.
In the REPEAT project, numerous STRs in a genome of Atlantic cod (Gadus morhua) were identified and their variability associated with adaptation to environment. Atlantic cod is a benthopelagic fish widely spread in the Atlantic Ocean, in waters characterized by various temperatures, salinities and oxygen content. Physiology, behaviour and ecology of cod are affected by water conditions, therefore, fish adapted to certain conditions struggle to maintain homeostasis and preserve energy if conditions change.
Here, I will talk about how I’m planning on validating the influence of variable STR lengths identified in candidate genes on the adaptations to the changeable environmental factors, using both cell lines and a fish experimental model: Japanese medaka (Oryzias latipes).