engleski

Centromere of the nematode Meloidogyne ; characterization of centromere specific H3 protein (CENH3) and underlying DNA sequences

Centromeres are chromosomal domains essential for proper segregation of genetic material in cell divisions. They are defined epigenetically by the presence of centromere-specific histone H3 protein (CENH3). CENH3 histone is a species-specific protein, particularly variable in its N-terminal domain which is associated with centromeric DNA. In contrast to conserved function of the centromere, CENH3 and centromeric DNA evolve rapidly in diverse organisms. Why the centromere is composed of unstable units is still unsolved question. Nematodes Meloidogyne have some exceptional characteristics, such as presumptive holocentric organization of the centromere and specific mode of reproduction by mitotic parthenogenesis, which make them an ideal system to study centromere structure and function. Interestingly, our genome analysis of centromere protein CENH3 in Meloidogyne incognita reveal three divergent genes for CENH3 (α, β, λ), which are completely conserved in its related species. Transcriptome data show developmental stage-specific expression of CENH3 variants. Immunostaining of chromosomes with antibodies specific for αCENH3 reveals so far unseen distribution of CENH3 in forms of monocentric, dicentric, polycentric and holocentric centromeres. ChIP experiments suggested that different repetitive sequences with conserved 21-nt motif may be associated with αCENH3 domains.

centromere ; CENH3 ; nematode

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