engleski

Root-knot nematodesas a model for centromere (epi)genomics and satellitome research

Root-knot nematodes (genus Meloidogyne) are established as important model organisms of plant parasites. Their characteristics, such as holocentric chromosomes, polyploidy and parthenogenesis make them an ideal system to study genome evolution, speciation processes, and centromere structure and function.In this regard, our analysis of centromere specific histone H3 (CENH3) in the genome of M. incognitareveals three divergent CENH3 variants instead of the commonly present only one. All CENH3 variants are completely conserved in related species, and transcriptome data show their developmental stage- specific expression. Immunostaining of chromosomes with antibodies specific for CENH3 variants reveals holocentric distribution pattern for each of them. Given that the centromere tends to be established upon satellite DNA arrays wefurther focus on their characterization in related Meloidogyne genomes. Using next-generation sequencing combined with novel bioinformatics tools we detected a remarkable collection of satellite DNAs (satellitome) in each genome. Comparative analyses of satellitomes indicate the species evolutionary history in accordance with a recent hypothesis which suggests a multiple hybridization events in species origin. All results will be discussed in terms of coexistence and possible roles of different CENH3 variants in holocentric centromeres, and correlated with trends in satellitome evolution

centromere ; satellitome ; nematodes

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