Molecular evolution of a reproductive barrier in maize and related species.
Three cross-incompatibility loci each control a distinct reproductive barrier in both domesticated maize (Zea mays ssp. mays) and its wild teosinte relatives. These 3 loci, Teosinte crossing barrier1 (Tcb1), Gametophytic factor1 (Ga1), and Ga2 , each play a key role in preventing hybridization betwe...
| Publicado en: | Genetics Vol. 230; no. 3; pp. 1 - 15 |
|---|---|
| Autores principales: | , , , , , , , , |
| Formato: | pictorial research tables/charts Journal Article |
| Publicado: |
Oxford University Press / USA
Jul2025
|
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=186630217&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 186630217 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00166731 GNT jtl: Genetics issn: 00166731 maglogo: N pubinfo: dt: Jul2025 vid: 230 iid: 3 pid: 622 pub: Oxford University Press / USA artinfo: ui: 186630217 186630217 186630217 10.1093/genetics/iyaf085 186630217 ppf: 1 ppct: 14 formats: tig: atl: Molecular evolution of a reproductive barrier in maize and related species. aug: au: Cryan, Elli Phinney, Garnet Seetharam, Arun S Evans, Matthew M S Kellogg, Elizabeth A Zhan, Junpeng Meyers, Blake Kliebenstein, Daniel J Ross-Ibarra, Jeffrey affil: Plant Sciences, University of California Davis, Davis, CA 95616, USA sug: subj: Evolution Reproduction Corn Genes RNA, Small Interfering Pollen Plant Proteins Phylogenetics Haplotypes Sequence Analysis DNA Methylation Genetic Techniques Funding Source ab: Three cross-incompatibility loci each control a distinct reproductive barrier in both domesticated maize (Zea mays ssp. mays) and its wild teosinte relatives. These 3 loci, Teosinte crossing barrier1 (Tcb1), Gametophytic factor1 (Ga1), and Ga2 , each play a key role in preventing hybridization between incompatible populations and are proposed to maintain the barrier between domesticated and wild subspecies. Each locus encodes both a silk-active and a matching pollen-active pectin methylesterase (PMEs). To investigate the diversity and molecular evolution of these gametophytic factor loci, we identified existing and improved models of the responsible genes in a new genome assembly of maize line P8860 that contains active versions of all 3 loci. We then examined 52 assembled genomes from 17 species to classify haplotype diversity and identify sites under diversifying selection during the evolution of these genes. We show that Ga2 , the oldest of these 3 loci, was duplicated to form Ga1 at least 12 million years ago. Tcb1 , the youngest locus, arose as a duplicate of Ga1 before or around the time of diversification of the Zea genus. We find evidence of positive selection during evolution of the functional genes at an active site in the pollen-expressed PME and predicted surface sites in both the silk- and pollen-expressed PMEs. The most common allele at the Ga1 locus is a conserved ga1 allele (ga1-Off), which is specific haplotype containing 3 full-length PME gene copies, all of which are noncoding due to conserved stop codons and are between 610 thousand and 1.5 million years old. We show that the ga1-Off allele is associated with and likely generates 24-nt siRNAs in developing pollen-producing tissue, and these siRNAs map to functional Ga1 alleles. In previously published crosses, the ga1-Off allele was associated with reduced function of the typically dominant functional alleles for the Ga1 and Tcb1 barriers. Taken together, this seems to be an example of an allele at a reproductive barrier locus being associated with an as yet undetermined mechanism capable of silencing the reproductive barrier. pubtype: Academic Journal doctype: pictorial research tables/charts Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
|---|