Spatial distribution and molecular identification of small mammals in the areas of natural focus disease in Qinghai Province / 中华地方病学杂志

ABSTRACT

Objective:To understand the spatial distribution of small mammals in the areas of natural focus disease in Qinghai Province, and to identify captured small mammals at the molecular level using mitochondrial cytochrome C oxidase subunit I (COI) gene as molecular marker.Methods:In 2009 - 2016, the distribution of regional spatial, elevation distribution and ecological environment type of captured small mammals were analyzed in 16 cities (counties) of 6 prefectures in Qinghai Province. The partial COI gene fragment sequence (about 650 bp in length) was obtained by PCR amplification, which was further analyzed through homology comparison, genetic distance and phylogenetic analysis.Results:Totally 1 631 small mammals were captured that had belonged to 30 species of 21 genera, 7 families, 3 orders. Among them there were 926 rodent animals that had belonged to 25 species of 19 genera, 5 families, accounting for 56.78%. There was the largest number in Golmud (313 animals), the highest distribution of small mammals was found at the elevation of 2 800 - < 3 000 m (532 animals), the largest number of small mammals was found in the sandy grassland (612 animals). COI genes of 292 small mammals were successfully amplified, and the homology was consistent with the target sequence. The results showed that the intraspecific genetic distance ranged from 0.01% to 2.90%, interspecific genetic distance ranged from 4.00% to 12.00%, intergenus genetic distance was 13.00% - 21.00% and interfamily genetic distance was 22.00% - 25.00%. The interspecific genetic distance was significantly greater than the intraspecific genetic distance. Neighbor-Joining tree showed that the same species were clustered into a single branch with high support form a total of 20, with a confidence level of 98% to 100%.Conclusions:The spatial distribution of small mammals is influenced by geographical factors such as region, elevation and ecological environment in Qinghai Province. Molecular identification can make up for the shortcomings in morphological identification.