36 Oral - Platform Session #3 Speciation, Hybridization, and Introgression
Thursday June 09, 11:35 AM - 11:50 AM

When and how is introgression adaptive? A tale from two widely distributed sympatric oak species


Authors:
Ruirui Fu 1; Yuxiang Zhu 1; Ying Liu 1; Yu Feng 2; Rui-Sen Lu 3; Yao Li 4; Pan Li 1; Antoine Kremer 5; Martin Lascoux 6; Jun Chen 1

Affiliations:
1) College of Life Sciences, Zhejiang University, China; 2) Chengdu Institute of Biology, Chinese Academy of Sciences, China; 3) Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, China; 4) College of Biology and the Environment, Nanjing Forestry University, China; 5) UMR BIOGECO, INRAE, Université de Bordeaux,France; 6) Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Sweden

Keywords:
Speciation & hybridization

Introgression is a crucial source of new alleles, perhaps even more important than standing variation, for adaption under rapidly changing environment. Though introgression has been extensively studied in many plants and animals, key questions on the underlying mechanisms of introgression still remain unanswered. In particular, what is the genomic distribution of introgressed regions along the genome, are the level and pattern of introgression influenced by ecological factors, and if so when and how does introgression contribute to adaptation? By investigating introgression between two sympatric widespread Asian oak species, Q. acutissima and Q. variabilis sampled in multiple forests and for which we have generated high quality genomic resources, we show that introgressed regions are broadly distributed along the genome. Introgression depends on genetic divergence between pairs of populations and on the similarity of the environments in which they live. Oak populations occupying similar ecological sites tend to share the same introgressed regions and introgressed genomic footprints of adaptation are preferentially located in regions with suppressed recombination rate. Introgression confers adaptation by introducing allelic variation in cis-regulatory elements, in particular through TE insertions, thereby altering the regulation of genes related to stress. Our results provide new avenues of research for uncovering the mechanism of adaptation in sympatric species.