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睾丸中的广泛转录扫描调节基因进化速率
作者:小柯机器人 发布时间:2020/2/3 9:23:21

美国纽约大学Itai Yanai团队发现,睾丸中的广泛转录扫描调节基因进化速率。这一研究成果2020年1月23日发表在国际学术期刊《细胞》上。

研究人员表示,睾丸表达了所有哺乳动物器官中数量最多的基因,这一发现长期困扰着分子生物学家。
 
通过人类和小鼠精子发生的单细胞转录组数据,研究人员为此提供了证据,并表明这种广泛的转录通过被称为转录扫描的机制纠正DNA损伤,从而维持了雄性生殖细胞中DNA序列的完整性。研究人员发现,在精子发生过程中表达的基因在转录链上显示出较低的突变率,并且在群体中具有较低的多样性。此外,通过精子发生过程中基因表达的水平可以微调这种效果。未表达的基因在模型中没有从转录扫描中受益,它们在进化时间尺度上的分化更快,并且在感觉和免疫防御功能上也很丰富。总的来说,研究人员认为转录扫描以基因特异的方式改变生殖细胞突变特征并调节突变率,从而维持大部分基因的DNA序列完整性,但在特定基因亚群中允许更快地进化。
 
附:英文原文
 
Title: Widespread Transcriptional Scanning in the Testis Modulates Gene Evolution Rates

Author: Bo Xia, Yun Yan, Maayan Baron, Florian Wagner, Dalia Barkley, Marta Chiodin, Sang Y. Kim, David L. Keefe, Joseph P. Alukal, Jef D. Boeke, Itai Yanai

Issue&Volume: 2020/01/23

Abstract: The testis expresses the largest number of genes of any mammalian organ, a findingthat has long puzzled molecular biologists. Our single-cell transcriptomic data ofhuman and mouse spermatogenesis provide evidence that this widespread transcriptionmaintains DNA sequence integrity in the male germline by correcting DNA damage througha mechanism we term transcriptional scanning. We find that genes expressed duringspermatogenesis display lower mutation rates on the transcribed strand and have lowdiversity in the population. Moreover, this effect is fine-tuned by the level of geneexpression during spermatogenesis. The unexpressed genes, which in our model do notbenefit from transcriptional scanning, diverge faster over evolutionary timescalesand are enriched for sensory and immune-defense functions. Collectively, we proposethat transcriptional scanning shapes germline mutation signatures and modulates mutationrates in a gene-specific manner, maintaining DNA sequence integrity for the bulk ofgenes but allowing for faster evolution in a specific subset.

DOI: 10.1016/j.cell.2019.12.015

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)31377-7

期刊信息
Cell:《细胞》,创刊于1974年。隶属于细胞出版社,最新IF:36.216
官方网址:https://www.cell.com/