The Parental Centromere Sizes Remain Unaltered in Allopolyploid Wheat-Rye Hybrids.

Introduction: In chromatin nucleosomes, the presence - instead of canonical histone H3 - of its variant, CENH3 (in plants), is considered the most reliable marker of the location of centromeres. In this study, we investigated the effects of distant hybridization and maternal cytoplasm on centromere size in allopolyploid hybrids between wheat and rye as compared to their parental forms.

Methods: Centromere sizes were measured using 2D images of CENH3 fluorescent signals on interphase nuclei obtained from parental forms and a triticale hybrid (genomic formula AABBBRR), in which the maternal form is wheat and secalotriticum hybrids (genomic formula RRAABBB) in which the maternal form is rye.

Expression of Two Rye CENH3 Variants and Their Loading into Centromeres.

Gene duplication and the preservation of both copies during evolution is an intriguing evolutionary phenomenon. Their preservation is related to the function they perform. The central component of centromere specification and function is the centromere-specific histone H3 (CENH3).

Conserved molecular structure of the centromeric histone CENH3 in Secale and its phylogenetic relationships.

It has been repeatedly demonstrated that the centromere-specific histone H3 (CENH3), a key component of the centromere, shows considerable variability between species within taxa. We determined the molecular structure and phylogenetic relationships of CENH3 in 11 Secale species and subspecies that possess distinct pollination systems and are adapted to a wide range of abiotic and biotic stresses. The rye (Secale cereale) genome encodes two paralogous CENH3 genes, which differ in intron-exon structure and are transcribed into two main forms of the protein, αCENH3 and βCENH3.