Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland.
Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
Sci Adv. 2023 May 24;9(21):eadf1773. doi: 10.1126/sciadv.adf1773.
Mutations to gene regulatory networks can be maladaptive or a source of evolutionary novelty. Epistasis confounds our understanding of how mutations affect the expression patterns of gene regulatory networks, a challenge exacerbated by the dependence of epistasis on the environment. We used the toolkit of synthetic biology to systematically assay the effects of pairwise and triplet combinations of mutant genotypes on the expression pattern of a gene regulatory network expressed in that interprets an inducer gradient across a spatial domain. We uncovered a preponderance of epistasis that can switch in magnitude and sign across the inducer gradient to produce a greater diversity of expression pattern phenotypes than would be possible in the absence of such environment-dependent epistasis. We discuss our findings in the context of the evolution of hybrid incompatibilities and evolutionary novelties.
基因突变可能是适应不良的，也可能是进化新奇的来源。上位性混淆了我们对突变如何影响基因调控网络表达模式的理解，而这种混淆因上位性对环境的依赖而加剧。我们使用合成生物学工具包系统地检测了突变基因型的成对和三聚体组合对基因调控网络表达模式的影响，该网络在空间域上解释了诱导剂梯度。我们发现了大量的上位性，其幅度和符号可以在诱导剂梯度上切换，从而产生比没有这种环境依赖上位性时更多样的表达模式表型。我们在杂交不亲和性和进化新奇性的进化背景下讨论了我们的发现。
