Paternity, Cooperative Breeding, and Genetic Chimerism in Callitrichids

马蹄莲的父系、合作育种和遗传嵌合现象。弗伦奇和科琳娜罗斯绒猴是新世界的猴科Callitrichidae形成大型合作繁殖群体，其中许多个体照顾繁殖对的后代。为了解释这种行为的基础上的间接健身效益的帮助提供者，有必要确定真正的遗传关系的个人。这对绒猴来说并不容易，因为它们有独特的生殖系统。 绒猴产生异卵双胞胎，其胎盘在早期胚胎发育期间融合，导致双胞胎之间通过血液流动进行基因交换。这种基因交换导致婴儿成为基因嵌合体，其组织混合了具有自己DNA的细胞和具有双胞胎DNA的细胞。关于基因交换的程度以及哪些组织受到影响，我们知之甚少。这项研究将使用微卫星遗传标记来评估发育过程中双胞胎之间遗传交换的程度和分布。将使用从繁殖群体中存档的标本，对来自双组已知的库利Callithrix kuhlii雌-雄配对的至少10种组织进行分析。进一步的研究将评估包含多个雄性的繁殖组的遗传亲子关系，以确定是否有可能多个雄性繁殖一对双胞胎。水平遗传交换的记录可能会极大地影响由于个体之间共享等位基因的增加而导致的间接适合度的计算。对这一独特系统的研究将深入了解影响异体父母照顾、亲属识别和亲属选择的机制，并可能改变目前对社会行为演变的看法。

Paternity, Cooperative Breeding, and Genetic Chimerism in CallitrichidsPI: Guillermo Orti, Jeffrey A. French and Corinna RossMarmosets are New World monkeys of the family Callitrichidae that form large cooperative breeding groups in which many individuals care for the offspring of the breeding pair. In order to explain this behavior based on indirect fitness benefits for the help providers, it is necessary to determine the true genetic relationship among individuals. This is not easy to do for marmosets because of their unique reproductive system. Marmosets produce fraternal twins, whose placentas fuse during early embryonic development, resulting in genetic exchange through the blood flowing between the twins. This genetic exchange causes the infants to be genetic chimeras, having tissues with mixtures of cells with their own DNA and cells with the DNA of their twin. Little is known about the extent of genetic exchange and what tissues are affected. The proposed study will use microsatellite genetic markers to assess the extent and distribution of genetic exchange between twins during development. At least ten types of tissues from twin sets of known female-male pairings of Callithrix kuhlii will be assayed, using specimens archived from a breeding colony. Further studies will assess genetic paternity in the breeding groups that contained multiple males, in order to determine whether it is possible that multiple males are siring a single set of twins. Documentation of horizontal genetic exchange may drastically affect calculations of indirect fitness due to an increase in shared alleles between individuals. The study of this unique system will provide insights into the mechanisms affecting alloparental care, kin recognition, and kin selection and may alter current views of the evolution of social behavior.