Abstract
Centromeres are essential for correct chromosome segregation during cell division and are determined by the presence of centromere-specific histone 3 (CENH3). Most of the diploid plant species, in which the structure and copy number of CENH3 genes have been determined, have this gene as a singleton; however, some cereal species in the tribe Triticeae have been found to have CENH3 in two variants. In this work, using the set of the wheat-rye addition lines we wanted to establish the chromosomal assignment of the CENH3 genes in the cultivated rye, Secale cereale (Linnaeus, 1753), in order to expand our knowledge about synteny conservation in the most important cereal species and about their chromosome evolution. To this end, we have also analyzed data in available genome sequencing databases. As a result, the αCENH3 and βCENH3 forms have been assigned to rye chromosomes 1R and 6R: specifically, the commonest variants αCENH3v1 and βCENH3v1 to chromosome 1R, and the rare variants, αCENH3v2 and probably βCENH3v2, to chromosome 6R. No other CENH3 variants have been found by analysis of the rye genome sequencing databases. Our chromosomal assignment of CENH3 in rye has been found to be the same as that in barley, suggesting that both main forms of CENH3 appeared in a Triticeae species before the barley and wheatrye lineages split.
Highlights
In centromeric nucleosomes, canonical histone H3 appears in the form of its centromerespecific modification denoted in plants as centromere-specific histone 3 (CENH3)
The presence of at least two copies of the CENH3 gene is a shared feature of the species in the tribe Triticeae, and this gene had probably been duplicated before the barley and wheat‐rye lineages split, which is variously reported to date back to 8‐9 MYA (Middleton et al 2014) or 11.6 MYA (Martis et al 2012)
Three CENH3 variants described in the oats Avena sativa Linnaeus, 1753 (Ishii et al 2015) represent the alpha form and two forms of CENH3 appear for the first time in the closest rye relatives: the Triticeae genera barley, wheat and Aegilops (Sanei et al 2011, Yuan et al 2015)
Summary
Canonical histone H3 appears in the form of its centromerespecific modification denoted in plants as CENH3 The presence of this protein is by far the most distinct molecular feature of this chromosomal region. Unlike canonical histone H3, which has a conserved structure, CENH3 normally shows considerable variability across species (Sanei et al 2011, Maheshwari et al 2015, Neumann et al 2015). Different domains of this molecule are diverging differently. The chromosomal localization of the CENH3 genes in the other Triticeae species has been beyond the scope of any study known to us
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.