Diversity Of Gasterophilus Spp. In Mongol-Xinjiang Region And Qinghai Tibet Region And Analysis Of Population Genetic Structure Of Gasterophilus Spp.

Gasterophilosis is a significant threat to equids, especially Przewalski’s horses (listed as endangered by the IUCN). A parasitological survey for Gasterophilus spp. was done at equids in three regions:the Kalamaili Nature Reserve (KNR), Xinjiang, and Duolun, Inner Mongolia in Mongol-Xinjiang region, Maduo, Qinghai Province in Qinghai Tibet region to investigate and analyze the infection and diversity of Gasterophilus spp. in the desert, desert-steppe and cold alpine steppe of these regions. The results showed:infection with Gasterophilus larvae is very common in horses in all these regions and the intensity of infection in Mongol-Xinjiang region was higher; the highest species diversity was found in Mongol-Xinjiang region than Qinghai Tibet region; the diversity of Gasterophilus spp. was influenced by the environmental living conditions of its host, G. pecorum has successful reproductive strategies that adapts to the harsh environmental conditions.G pecorum was the dominant botfly species attacking the equids in the KNR. A population genetic structure analysis was conducted on the larvae of G pecorum, G nasalis and G nigricornis from sympatric host species using mitochondrial cytochrome oxidase subunit I (COI) gene. The results indicated that the Gasterophilus larvae infecting one host had multiple maternal ancestors; little genetic differentiation of three Gasterophilus spp. species was found between different host species, G. pecorum infections within Przewalski’s horses were mainly transmitted from Asiatic wild asses and the domestic horse was the likely source of G. nasalis and G. nigricornis infection; a high degree of genetic differentiation was observed within each Gasterophilus spp. species, different parasite population genetic structure of G pecorum comparing with G nasalis and G nigricornis could be a reflection of its unique parasite life history traits.