Université Paris-Sud, UMR8626, Laboratoire de Physique Théorique et Modèles Statistiques, F-91405 Orsay, France.
Genetics. 2009 Oct;183(2):673-84, 1SI-8SI. doi: 10.1534/genetics.109.104174. Epub 2009 Aug 3.
Mutation and recombination are the two main forces generating genetic variation. Most of this variation may be deleterious. Because recombination can reorganize entire genes and genetic circuits, it may have much greater consequences than point mutations. We here explore the effects of recombination on models of transcriptional regulation circuits that play important roles in embryonic development. We show that recombination has weaker deleterious effects on the expression phenotypes of these circuits than mutations. In addition, if a population of such circuits evolves under the influence of mutation and recombination, we find that three key properties emerge: (1) deleterious effects of mutations are reduced dramatically; (2) the diversity of genotypes in the population is greatly increased, a feature that may be important for phenotypic innovation; and (3) cis-regulatory complexes appear. These are combinations of regulatory interactions that influence the expression of one gene and that mitigate deleterious recombination effects.
突变和重组是产生遗传变异的两个主要力量。大多数这种变异可能是有害的。因为重组可以重新组织整个基因和遗传回路，所以它可能比点突变具有更大的影响。我们在这里探讨了重组对在胚胎发育中发挥重要作用的转录调控回路模型的影响。我们表明，重组对这些回路的表达表型的有害影响比突变小。此外，如果在突变和重组的影响下进化了这样的电路种群，我们发现出现了三个关键特性：（1）突变的有害影响大大降低；（2）种群中的基因型多样性大大增加，这一特征可能对表型创新很重要；（3）出现顺式调控复合物。这些是影响一个基因表达并减轻有害重组效应的调控相互作用的组合。
