Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA.
Evolution. 2010 Sep;64(9):2587-600. doi: 10.1111/j.1558-5646.2010.01015.x.
What are imprinted genes doing in the adult brain? Genomic imprinting is when a gene's expression depends upon parent of origin. According to the prevailing view, the "kinship theory" of genomic imprinting, this effect is driven by evolutionary conflicts between genes inherited via sperm versus egg. This theory emphasizes conflicts over the allocation of maternal resources, and focuses upon genes that are expressed in the placenta and infant brain. However, there is growing evidence that imprinted genes are also expressed in the juvenile and adult brain, after cessation of parental care. These genes have recently been suggested to underpin neurological disorders of the social brain such as psychosis and autism. Here we advance the kinship theory by developing an evolutionary model of genomic imprinting for social behavior beyond the nuclear family. We consider the role of demography and mating system, emphasizing the importance of sex differences in dispersal and variance in reproductive success. We predict that, in hominids and birds, altruism will be promoted by paternally inherited genes and egoism will be promoted by maternally inherited genes. In nonhominid mammals we predict more diversity, with some mammals showing the same pattern and other showing the reverse. We discuss the implications for the evolution of psychotic and autistic spectrum disorders in human populations with different social structures.
印记基因在成人大脑中做什么？基因组印记是指一个基因的表达取决于其来自父本还是母本。根据目前占主导地位的观点，即基因组印记的“亲缘关系理论”，这种效应是由通过精子或卵子遗传的基因之间的进化冲突驱动的。该理论强调了在母体资源分配上的冲突，并集中于在胎盘和婴儿大脑中表达的基因。然而，越来越多的证据表明，印记基因在停止父母照顾后，也在青少年和成人大脑中表达。这些基因最近被认为是精神分裂症和自闭症等社交大脑神经紊乱的基础。在这里，我们通过为超越核心家庭的社会行为开发一种基因组印记的进化模型，来推进亲缘关系理论。我们考虑了人口统计学和交配系统的作用，强调了在扩散中的性别差异和繁殖成功率的差异的重要性。我们预测，在人类和鸟类中，父系遗传的基因将促进利他主义，而母系遗传的基因将促进利己主义。在非人类哺乳动物中，我们预测会有更多的多样性，一些哺乳动物表现出相同的模式，而其他哺乳动物则表现出相反的模式。我们讨论了不同社会结构的人类群体中精神分裂症和自闭症谱系障碍进化的影响。
