Doctoral Dissertation Improvement: Development of Genomic Methods to Clarify the Evolution of Life History Trade-offs.

Wayne State University, Detroit MI

Investigators

Abstract

Pregnancy is a hallmark of reproductive success, yet historically little attention has been paid to the study of nonhuman primate pregnancy relative to other key factors in reproduction such as sexual selection, competition, and parental care of offspring. This study builds on others to further develop an accurate New World monkey phylogeny that allows changes in life history traits to be traced within an evolutionary context. This research also advances a female in science and trains high school and undergraduate students in laboratory techniques and genetics. The research takes a comparative genomic and phylogenetic approach to examine the role of pregnancy with respect to reproductive factors within a unique study population. The callitrichine clade (marmosets, tamarins and Goeldi's monkeys) of New World monkeys is an ideal group in which to study the evolution of pregnancy because of natural variation in the number of offspring produced per litter. Moreover, marmosets exhibit twin-twin germline chimerism, in which individuals carry the reproductive cells of their (fraternal) littermates. In addition, the generation of a Goeldi's monkey transcriptome allows examination of the evolutionary history of thousands of genes in callitrichines, explicitly testing hypotheses that genes involved in litter size and chimerism (e.g. genes involved in placentation, growth, immunity, and vasculogenesis) show evidence of adaptive evolution coincident with the timing of the changes in pregnancy. Testing hypotheses about which genes have undergone adaptations in callitrichine lineages will fill a gap in knowledge about the molecular underpinnings of the fascinating biology exhibited by these primates, and will lay the foundation for future studies in primate biology. Finally, the genotyping of individuals within a well-pedigreed colony tests whether Goeldi's monkey has retained chimerism, despite having lost the ability to twin. These findings will have implications in understanding the evolution of parental care and also will provide clues into how immune tolerance is established and maintained during evolution.