关键词: 着丝点, 着丝粒组蛋白H3, 着丝粒DNA, 植物染色体, 着丝粒

Abstract:

Centromeres are the chromosomal domains necessary for faithful chromosome segregation and transmission during mitosis and meiosis in eukaryotes. In the last decade, centromeres in some plant species including Arabidopsis, rice and maize have been deeply studied at molecular level. Centromeric DNAs evolve rapidly and are little conserved among various plants, but the types of centromeric DNA sequences and their organization patterns within centromeres are basically similar in plants. Plant centromeres are usually composed of clusters of tandemly arrayed satellite repeats that are interspersed with centromere-specific retrotransposons. In contrast to centromeric DNA, structural and transient centromeric/kinetochoric proteins are conserved among eukaryotes including plants. As the cases in other eukaryotes, the presence of CENH3 (centromeric histone H3)-containing nucleosomes is the fundamental feature of plant functional centromeres, and CENH3 plays critical roles in the identity and maintenance of plant centromeric chromatin.