RII Track-4: A role for epigenetic modifications driving seasonal patterns of reproduction?

点击翻译按钮获取中文摘要

Non-technical DescriptionTemperate and arctic regions experience dramatic variations in environmental conditions across the year. For animals to be able to successfully rear offspring in these environments, reproduction must be limited to a short window of time that ensures favorable conditions (i.e., mild temperatures and abundant food resources). While prior research has revealed how male animals prepare for mating, much less is known regarding how females precisely time reproduction (and thus, the time when offspring are born or hatch), even though it is female timing that ultimately dictates when rearing of offspring will occur. Traits expressed by an individual (i.e., phenotype) are shaped by interactions between an animal's genetics and the environment. This project will enable training at Columbia University and knowledge transfer of techniques and skills aimed at uncovering the genetic processes that are capable of responding to the environment and regulating expression of key genes to influence female reproductive timing decisions. This training and knowledge transfer will enhance the research capabilities of the PI's laboratory and facilitate future collaborations within the PI's home institution of North Dakota State University and beyond. Such knowledge will not only contribute to robust basic knowledge, but also has the potential to enhance animal livestock breeding programs (e.g., sheep, which are seasonal breeders) to enhance economic productivity.Technical DescriptionAn organism's phenotype is the result of interactions between its genome and the environment. Understanding the processes that influence an individual's evolutionary fitness (i.e. lifetime reproductive success) requires investigations of the molecular architecture that shape an individual's phenotype. One primary way whereby the environment can influence which genes are expressed (which gives rise to the phenotype) is via epigenetic modification. The ability of an individual to produce and successfully rear young directly dictates an individual?s evolutionary fitness. In animals inhabiting temperate or arctic clines, reproduction must be limited to a short window of time that ensures favorable conditions for rearing offspring. Seasonal epigenetic modification of the DNA regulating production of yolk-precursor proteins may enable appropriate annual responses, inhibiting production of yolk precursors when favorable conditions are experienced at inappropriate times of year (e.g., the late winter warm period) while enabling yolk precursor production when favorable conditions are experienced in the appropriate season. Utilizing a songbird model of seasonal breeding, the Dark-eyed Junco (Junco hyemalis), this proposal will test the novel hypothesis that methylation of DNA in the regulatory region of an important gene needed for yolking and final follicle maturation is seasonally modulated. This project will provide training and transfer of knowledge of the skills and tools utilized to uncover epigenetic modifications that may influence an individual's phenotype and fitness. The training received at Columbia University for methods of detecting methylation in the genome will allow our group to test the hypothesis that seasonal information influences epigenetic modulation of the promoter region of a gene the codes for a key yolk pre-cursor protein, vitellogenin (VTG).