engleski

Comparative satellitome analysis reveals the polyploid hybrid origin in holocentric nematodes

Satellite DNAs (satDNAs) are tandemly repeated non-coding DNA sequences, and the most common constituents of every functional centromere. Holocentric chromosomes and multiple genome copies establish nematodes of the genus Meloidogyne as an attractive model for studying centromere- associated DNA sequences. In order to identify a pool of satDNAs that may be involved in genomics of the holocentromere, we have analyzed the satellitome (whole-genome complement of satDNAs) in four different publicly available Meloidogyne genomes using RepeatExplorer computational tool. Our results of genome-wide analyses revealed the presence of a remarkable collection of 38-80 different satDNAs in each examined genome. In addition, comparative analyses of satellitomes show three main groups of satDNAs ; common for all four studied species, and shared by subsets of three or only two species. This distribution of satDNAs supports a recent hypothesis based on comparative analyses of coding regions, that speciation processes in Meloidogyne may be a result of additive interspecific hybridizations. Our preliminary analysis of satDNA distribution on chromosomes of studied species also speaks in favor of such unusual genome evolution in Meloidogyne.

satellitome ; nematodes ; evolution

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