Year: 2016
Type: article
Abstract: Sex-chromosome research in plants is fragmented among many species and research platforms.Th is fragmentation has occurred in part because dioecy has evolved repeatedly across phylogenetically diverse plant taxa, though it is uncommon in most land plant lineages excepting gymnosperms ( Renner, 2014 ).Furthermore, genetic sex determination by sex chromosomes is one of many mechanisms that may regulate dioecy, including environmental, epigenetic, and single-locus sex determination ( Renner, 2014( Renner, , 2016 ) ). Sex chromosomes have only been identifi ed in four species of liverworts, one species of bryophyte, fi ve species of gymnosperms, and 39 species across 14 families of angiosperms, though with advances in genomic sequencing and analysis, doubtless more will be found ( Ming et al., 2011 ).Genomic advances have already contributed to the emergence of many "model" systems useful for studying sex chromosomes including many that can be found at the grocery store, such as asparagus, strawberry, papaya, and kiwifruits among others.Despite the deluge of new information from recognizable species, however, it appears as though we are working with small pieces of the puzzle in seemingly disparate systems.A more holistic approach, from understanding the developmental genetics underpinning sex determination to the ecological context under which sex chromosomes arise, is needed.Understanding how sex chromosomes form and the selective pressures that govern their evolution can be greatly enhanced by ( 1) identifying what genes or pseudogenes determine sex within a given species, (2) comparing phylogenetic patterns and parallel evolution (or lack thereof) among these genes and the genomic regions in which they reside, and (3) understanding ecological pressures that infl uence males and females within a habitat to drive divergence between sex chromosomes.Advances across this spectrum are being made in numerous plant sex-chromosome systems, even if one all-encompassing system remains elusive.
Source: American Journal of Botany
DOI: 10.3732/ajb.1600054
Authors: Richard C. Moore, Alex E. Harkess, Laura A. Weingartner
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2470572685