Epigenetic Divergence during Early Stages of Speciation in an African Crater Lake Cichlid Fish
Epigenetic Divergence during Early Stages of Speciation in an African Crater Lake Cichlid Fish
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非洲火山口湖慈鲷鱼物种形成早期的表观遗传分化
DOI：
10.1101/2021.07.30.435319
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Vernaz G
中科院分区：
文献类型：
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作者：
Vernaz G
表观遗传变异可以改变转录，促进面临不同环境挑战的群体之间的表型分化。在这里，我们评估的表观遗传基础的多样化在早期阶段的物种形成。具体来说，我们专注于非常年轻的辐射ofAstatolipia callipterain火山口湖马索科，坦桑尼亚南部的DNA甲基化分歧的程度和功能的相关性。我们的研究集中在两个湖泊生态形态，分歧约1,000年前和人口在附近的河流，他们分离约10,000年前。这两个湖泊生态形态没有固定的遗传分化，但其特点是不同的形态，深度偏好和饮食。我们报告了两个湖泊生态形态之间以及湖泊和河流种群之间广泛的全基因组甲基化组差异，这些差异与关键的生物过程有关，并与生态相关基因的转录活性改变有关。这些基因之间的湖泊生态不同，包括参与类固醇代谢，血红蛋白组成和红细胞生成，符合他们的不同栖息地占用。使用一个共同的花园实验，我们发现，全球甲基化谱往往迅速重塑跨代，但生态特异性差异可以遗传。总的来说，我们的研究表明表观遗传对脊椎动物物种形成的早期阶段的贡献。
Epigenetic variation can alter transcription and promote phenotypic divergence between populations facing different environmental challenges. Here, we assess the epigenetic basis of diversification during the early stages of speciation. Specifically, we focus on the extent and functional relevance of DNA methylome divergence in the very young radiation ofAstatotilapia callipterain crater Lake Masoko, southern Tanzania. Our study focuses on two lake ecomorphs that diverged approximately 1,000 years ago and a population in the nearby river from which they separated approximately 10,000 years ago. The two lake ecomorphs show no fixed genetic differentiation, yet are characterized by different morphologies, depth preferences and diets. We report extensive genome-wide methylome divergence between the two lake ecomorphs, and between the lake and river populations, linked to key biological processes and associated with altered transcriptional activity of ecologically relevant genes. Such genes differing between lake ecomorphs include those involved in steroid metabolism, hemoglobin composition and erythropoiesis, consistent with their divergent habitat occupancy. Using a common-garden experiment, we found that global methylation profiles are often rapidly remodeled across generations but ecomorph-specific differences can be inherited. Collectively, our study suggests an epigenetic contribution to the early stages of vertebrate speciation.