The recombination landscape of introgression in yeast

Author:

Schwarzkopf Enrique J.1ORCID,Brandt Nathan1,Smukowski Heil Caiti1ORCID

Affiliation:

1. Department of Biological Sciences, North Carolina State University

Abstract

Meiotic recombination is an important evolutionary force that acts by breaking up genomic linkage, thereby increasing the efficacy of selection. Meiotic recombination is initiated with a double-strand break which is resolved via a crossover, which involves the reciprocal exchange of genetic material between homologous chromosomes, or a non-crossover, which results in small tracts of non-reciprocal exchange of genetic material. While the meiotic process is largely conserved, crossover and non-crossover rates vary between species, populations, individuals, and across the genome. In recent years, recombination is observed to be positively associated with the distribution of ancestry derived from past interspecific hybridization (introgression) in a variety of species. This trend has been interpreted to signify that introgression carries genetic incompatibilities that are selected against, such that introgression is enriched in regions of high recombination. However, recombination is well known to be suppressed in divergent sequence to prevent non-homologous recombination. Since introgressed DNA is often divergent, we sought to explore this interaction of recombination and introgression by sequencing spores and detecting crossover and non-crossover events from two crosses of the budding yeast Saccharomyces uvarum . One cross is between strains isolated from natural environments, and the other cross is between strains from fermentation environments, in which each strain contains introgression from their sister species, S. eubayanus . We find that the recombination landscape is significantly different between S. uvarum crosses, and that most of these differences can be explained by the presence of heterozygous introgression in the fermentation cross. Crossovers are significantly reduced and non-crossovers are increased in heterozygous introgression compared to syntenic regions in the natural cross without introgression. This translates to reduced allele shuffling within introgressed regions, and an overall reduction of shuffling on most chromosomes with introgression compared to the syntenic regions and chromosomes without introgression. Our results indicate that recent hybridization can significantly influence the recombination landscape, and suggest that the reduction in allele shuffling contributes to the initial purging of introgressed ancestry in the generations following a hybridization event.

Publisher

eLife Sciences Publications, Ltd

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3