The obscure events contributing to the evolution of an incipient sex chromosome in Populus: a retrospective working hypothesis - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Tree Genetics and Genomes Année : 2012

The obscure events contributing to the evolution of an incipient sex chromosome in Populus: a retrospective working hypothesis

Résumé

Genetic determination of gender is a fundamental developmental and evolutionary process in plants. Although it appears that dioecy in [i]Populus[/i] is genetically controlled, the precise gender-determining systems remain unclear. The recently released second draft assembly and annotated gene set of the [i]Populus[/i] genome provided an opportunity to revisit this topic. We hypothesized that over evolutionary time, selective pressure has reformed the genome structure and gene composition in the peritelomeric region of the chromosome XIX, which has resulted in a distinctive genome structure and cluster of genes contributing to gender determination in [i]Populus trichocarpa[/i]. Multiple lines of evidence support this working hypothesis. First, the peritelomeric region of the chromosome XIX contains significantly fewer single nucleotide polymorphisms than the rest of [i]Populus[/i] genome and has a distinct evolutionary history. Second, the peritelomeric end of chromosome XIX contains the largest cluster of the nucleotide-binding site–leucine-rich repeat (NBS–LRR) class of disease resistance genes in the entire [i]Populus[/i] genome. Third, there is a high occurrence of small microRNAs on chromosome XIX, which is coincident to the region containing the putative gender-determining locus and the major cluster of NBS–LRR genes. Further, by analyzing the metabolomic profiles of floral bud in male and female [i]Populus[/i] trees using a gas chromatography-mass spectrometry, we found that there are gender-specific accumulations of phenolic glycosides. Taken together, these findings led to the hypothesis that resistance to and regulation of a floral pathogen and gender determination coevolved, and that these events triggered the emergence of a nascent sex chromosome. Further studies of chromosome XIX will provide new insights into the genetic control of gender determination in [i]Populus[/i].

Dates et versions

hal-01267797 , version 1 (04-02-2016)

Identifiants

Citer

Gerald Tuskan, Steve Difazio, Patricia Faivre-Rampant, Muriel Gaudet, Antoine Harfouche, et al.. The obscure events contributing to the evolution of an incipient sex chromosome in Populus: a retrospective working hypothesis. Tree Genetics and Genomes, 2012, 8 (3), pp.559-571. ⟨10.1007/s11295-012-0495-6⟩. ⟨hal-01267797⟩
74 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More