Fundación Instituto Leloir, IIBBA-CONICET, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1405BWE3, Argentina.
The John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
New Phytol. 2019 Oct;224(1):55-70. doi: 10.1111/nph.15901. Epub 2019 Jun 18.
Pleiotropy occurs when one gene influences more than one trait, contributing to genetic correlations among traits. Consequently, it is considered a constraint on the evolution of adaptive phenotypes because of potential antagonistic selection on correlated traits, or, alternatively, preservation of functional trait combinations. Such evolutionary constraints may be mitigated by the evolution of different functions of pleiotropic genes in their regulation of different traits. Arabidopsis thaliana flowering-time genes, and the pathways in which they operate, are among the most thoroughly studied regarding molecular functions, phenotypic effects, and adaptive significance. Many of them show strong pleiotropic effects. Here, we review examples of pleiotropy of flowering-time genes and highlight those that also influence seed germination. Some genes appear to operate in the same genetic pathways when regulating both traits, whereas others show diversity of function in their regulation, either interacting with the same genetic partners but in different ways or potentially interacting with different partners. We discuss how functional diversification of pleiotropic genes in the regulation of different traits across the life cycle may mitigate evolutionary constraints of pleiotropy, permitting traits to respond more independently to environmental cues, and how it may even contribute to the evolutionary divergence of gene function across taxa.
当一个基因影响多个特征时，就会出现多效性，导致特征之间存在遗传相关性。因此，多效性被认为是对适应表型进化的一种限制，因为相关特征可能受到潜在的拮抗选择，或者功能特征组合得以保留。这种进化限制可能会通过调节不同特征的多效性基因的不同功能的进化而减轻。拟南芥开花时间基因及其作用途径是分子功能、表型效应和适应意义方面研究最透彻的基因之一。其中许多基因表现出强烈的多效性。在这里，我们回顾了开花时间基因多效性的例子，并强调了那些也影响种子发芽的例子。一些基因在调节这两个特征时似乎在相同的遗传途径中起作用，而其他基因在其调节中表现出功能多样性，要么以不同的方式与相同的遗传伙伴相互作用，要么可能与不同的伙伴相互作用。我们讨论了多效性基因在调节不同特征时在生命周期中的功能多样化如何减轻多效性的进化限制，使特征能够更独立地对环境线索做出反应，以及它如何甚至有助于跨分类群的基因功能的进化分歧。
