Narrow Genetic Diversity of Symbionts in Acrididae Grasshopper Hosts (Insecta, Orthoptera).

Bacteria of the genus are maternally inherited symbionts of Nematoda and numerous Arthropoda hosts. There are approximately 20 lineages of , which are called supergroups, and they are designated alphabetically. strains of the supergroups A and B are predominant in arthropods, especially in insects, and supergroup F seems to rank third. Host taxa have been studied very unevenly for symbionts, and here, we turn to one of largely unexplored insect families: Acrididae. On the basis of five genes subject to multilocus sequence typing, we investigated the incidence and genetic diversity of in 41 species belonging three subfamilies (Gomphocerinae, Oedipodinae, and Podisminae) collected in Turkey, Kazakhstan, Tajikistan, Russia, and Japan, making 501 specimens in total. Our results revealed a high incidence and very narrow genetic diversity of . Although only the strains belonging to supergroups A and B are commonly present in present, the Acrididae hosts here proved to be infected with supergroups B and F without A-supergroup variants. The only trace of an A-supergroup lineage was noted in one case of an inter-supergroup recombinant haplotype, where the gene came from supergroup A, and the others from supergroup B. Variation in the haplotypes in Acrididae hosts within supergroups B and F was extremely low. A comprehensive genetic analysis of diversity confirmed specific features of the allelic set in Acrididae hosts. This result can help to elucidate the crucial issue of biology: the route(s) and mechanism(s) of horizontal transmission.