Zhang Jianzhi
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109, USA.
Annu Rev Ecol Evol Syst. 2023 Nov;54:1-19. doi: 10.1146/annurev-ecolsys-022323-083451.
Pleiotropy refers to the phenomenon of one gene or one mutation affecting multiple phenotypic traits. While the concept of pleiotropy is as old as Mendelian genetics, functional genomics has finally allowed the first glimpses of the extent of pleiotropy for a large fraction of genes in a genome. After describing conceptual and operational difficulties in quantifying pleiotropy and the pros and cons of various methods for measuring pleiotropy, I review empirical data on pleiotropy, which generally show an L-shaped distribution of the degree of pleiotropy (i.e., the number of traits affected) with most genes having low pleiotropy. I then review the current understanding of the molecular basis of pleiotropy. The rest of the review discusses evolutionary consequences of pleiotropy, focusing on advances in topics including the cost of complexity, regulatory . coding evolution, environmental pleiotropy and adaptation, evolution of ageing and other seemingly harmful traits, and evolutionary resolution of pleiotropy.
多效性是指一个基因或一个突变影响多个表型性状的现象。虽然多效性的概念与孟德尔遗传学一样古老，但功能基因组学终于使人们首次得以初步了解基因组中大部分基因的多效性程度。在描述了量化多效性的概念和操作困难以及测量多效性的各种方法的优缺点之后，我回顾了关于多效性的实证数据，这些数据通常显示多效性程度（即受影响的性状数量）呈L形分布，大多数基因的多效性较低。然后，我回顾了目前对多效性分子基础的理解。综述的其余部分讨论了多效性的进化后果，重点关注包括复杂性成本、调控、编码进化、环境多效性与适应、衰老及其他看似有害性状的进化以及多效性的进化解决等主题的进展。
