Underrepresentation of active histone modification marks in evolutionarily young genes

• 来源期刊: 中国昆虫科学（英文版）
• 关键词: Drosophila H3K4me3 H3K36me3 H3K9me3 epigenetic evolution new gene evolution
• 年，卷（期）: 2017,（2）
• 页码范围: 174-186
• 页数: 13页
• 语种: 英文
• DOI: 10.1111/1744-7917.12299

摘要

It is known that evolutionarily new genes can rapidly evolve essential roles in fundamental biological processes.Nevertheless,the underlying molecular mechanism of how they acquire their novel transcriptional pattern is less characterized except for the role ofcis-regulatory evolution.Epigenetic modification offers an alternative possibility.Here,we examined how histone modifications have changed among different gene age groups in Drosophila melanogaster by integrative analyses of an updated new gene dataset and published epigenomic data.We found a robust pattern across various datasets where both the coverage and intensity of active histone modifications,histone 3 lysine 4 trimethylation and lysine 36 trimethylation,increased with evolutionary age.Such a temporal correlation is negative and much weaker for the repressive histone mark,lysine 9 trimethylation,which is expected given its major association with heterochromatin.By further comparison with neighboring old genes,the depletion of active marks of new genes could be only partially explained by the local epigenetic context.All these data are consistent with the observation that older genes bear relatively higher expression levels and suggest that the evolution of histone modifications could be implicated in transcriptional evolution after gene birth.