Open AccessRecurrent allopolyploidization, Y-chromosome introgression and the evolution of sexual systems in the plant genus Mercurialis
Author(s) -
Jörn F. Gerchen,
Paris Veltsos,
John R. Pannell
Publication year - 2022
Publication title -
philosophical transactions - royal society. biological sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.753
H-Index - 272
eISSN - 1471-2970
pISSN - 0962-8436
DOI - 10.1098/rstb.2021.0224
Subject(s) - biology , lineage (genetic) , introgression , evolutionary biology , reproductive isolation , locus (genetics) , genus , ploidy , plant evolution , dioecy , chromosome , genetics , zoology , botany , genome , gene , pollen , population , demography , sociology
The plant genusMercurialis includes dioecious, monoecious and androdioecious species (where males coexist with hermaphrodites). Its diversification involved reticulate evolution via hybridization and polyploidization. The Y chromosome of the diploid speciesMercurialis annua shows only mild signs of degeneration. We used sequence variation at a Y-linked locus in several species and at multiple autosomal and pseudoautosomal loci to investigate the origin and evolution of the Y chromosome across the genus. Our study provides evidence for further cases of allopolyploid speciation. It also reveals that all lineages with separate sexes (with one possible exception) share the same ancestral Y chromosome. Surprisingly, males in androdioecious populations of hexaploidM. annua carry a Y chromosome that is not derived from either of its two putative progenitor lineages but from a more distantly related perennial dioecious lineage via introgression. These results throw new light on the evolution of sexual systems and polyploidy inMercurialis and secure it as a promising model for further study of plant sex chromosomes.This article is part of the theme issue ‘Sex determination and sex chromosome evolution in land plants’.