The impacts of geographic and host species isolation on population divergence of Myxobolus lentisuturalis.

Samples of Myxobolus lentisuturalis were found in the gallbladder of Carassius auratus in Chongqing, China, without obvious disease symptoms, which were different from samples reported in Hubei, China, and Italy which were described as highly pathogenic muscle-infecting species. In order to improve our understanding of the relationships between these different samples, we analyzed geography, DNA sequence data, and site specificity. The results indicated that (1) the genetic relationship between Chongqing and Italy samples of M. lentisuturalis was much closer than relationship between each of them and the Hubei samples; (2) host species isolation was more important than the geographic isolation in divergence of M. lentisuturalis samples, and the species might be specialized among its different host species; and (3) geographic isolation and infection-site variation played a limited impact in genetic differentiation among different samples of M. lentisuturalis infecting the same host species.