研究揭示單卵雙胞胎生殖系基因組之間的差異
作者:
小柯機器人發布時間:2021/1/9 21:25:32
冰島大學Kari Stefansson、Daniel F. Gudbjartsson等研究人員合作揭示單卵雙胞胎生殖系基因組之間的差異。相關論文發表在2021年1月7日出版的《自然—遺傳學》雜誌上。
研究人員發現,單卵雙胞胎平均相差5.2個早期發育突變,並且大約15%的單卵雙胞胎具有大量特定於其中一個的這些早期發育突變。利用雙胞胎的父母和後代,研究人員確定了孿生前的突變。
研究人員觀察到在孿生前的細胞團中由單個細胞譜系形成雙胞胎的情況,以及由多個細胞譜系形成雙胞胎的情況。CpG>TpG突變的發生頻率隨著胚胎的發育而增加,這與DNA甲基化的增加相吻合。
這些結果表明,在發育過程中細胞的分配塑造了單卵雙胞胎之間的基因組差異。
據悉,儘管單卵雙胞胎在遺傳學研究中發揮了重要作用,但對其基因組差異仍知之甚少。
附:英文原文
Title: Differences between germline genomes of monozygotic twins
Author: Hakon Jonsson, Erna Magnusdottir, Hannes P. Eggertsson, Olafur A. Stefansson, Gudny A. Arnadottir, Ogmundur Eiriksson, Florian Zink, Einar A. Helgason, Ingileif Jonsdottir, Arnaldur Gylfason, Adalbjorg Jonasdottir, Aslaug Jonasdottir, Doruk Beyter, Thora Steingrimsdottir, Gudmundur L. Norddahl, Olafur Th. Magnusson, Gisli Masson, Bjarni V. Halldorsson, Unnur Thorsteinsdottir, Agnar Helgason, Patrick Sulem, Daniel F. Gudbjartsson, Kari Stefansson
Issue&Volume: 2021-01-07
Abstract: Despite the important role that monozygotic twins have played in genetics research, little is known about their genomic differences. Here we show that monozygotic twins differ on average by 5.2 early developmental mutations and that approximately 15% of monozygotic twins have a substantial number of these early developmental mutations specific to one of them. Using the parents and offspring of twins, we identified pre-twinning mutations. We observed instances where a twin was formed from a single cell lineage in the pre-twinning cell mass and instances where a twin was formed from several cell lineages. CpG>TpG mutations increased in frequency with embryonic development, coinciding with an increase in DNA methylation. Our results indicate that allocations of cells during development shapes genomic differences between monozygotic twins. Whole-genome sequencing of monozygotic twins, along with their parents, spouses and children, identifies postzygotic mutations present in the somatic tissue of one twin, but not the other, and characterizes differences in the number and timing of these mutations.
DOI: 10.1038/s41588-020-00755-1
Source: https://www.nature.com/articles/s41588-020-00755-1