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

怀孕是生殖成功的标志，但从历史上看，相对于生殖中的其他关键因素，如性别选择、竞争和父母对后代的照顾，对非人类灵长类怀孕的研究很少。这项研究建立在其他研究的基础上，以进一步发展准确的新世界猴子系统学，允许在进化背景下追踪生活史特征的变化。这项研究还促进了一名女性在科学方面的进步，并对高中生和本科生进行了实验室技术和遗传学方面的培训。该研究采用比较基因组学和系统发育学的方法，在一个独特的研究群体中检查怀孕对生殖因素的作用。由于每窝产下的后代数量存在自然变化，因此新大陆猕猴的Callitrichine分支(绒猴、Tamarins和Goeldi‘s猴子)是研究妊娠进化的理想类群。此外，绒猴表现出双胞胎生殖系嵌合体，在这种嵌合体中，个体携带他们(兄弟)后代的生殖细胞。此外，Goeldi‘s猴子转录组的产生可以检查Callitrichine中数千个基因的进化史，明确地测试与产仔数和嵌合体有关的基因(例如，涉及胎盘形成、生长、免疫和血管形成的基因)显示的适应性进化的证据与妊娠变化的时间一致的假设。测试关于哪些基因在软骨多糖谱系中经历了适应的假说将填补关于这些灵长类动物所展示的迷人生物学的分子基础的知识空白，并将为未来的灵长类生物学研究奠定基础。最后，在一个血统良好的群体中对个体进行基因分型，测试戈尔迪的猴子是否保留了嵌合体，尽管失去了双胞胎的能力。这些发现将对理解父母养育的进化有影响，也将为在进化过程中如何建立和维持免疫耐受提供线索。

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.