Dispersal route of the Asian house rat (Rattus tanezumi) on mainland China: insights from microsatellite and mitochondrial DNA

Abstract

BackgroundRattus tanezumi is a common commensal rat and an important host animal of bubonic plague in South China and Southeast Asia. The northward dispersal of this species in mainland China has been reported in recent decades, along with more recent intercontinental expansion. Population genetics of R. tanezumi in mainland China were studied to explain the relationship between dispersal history and the ancient and modern transportation networks of China.ResultsIn total, 502 individuals belonging to 18 populations were collected from 13 provincial areas. Nine microsatellite loci and two mtDNA sequences were analyzed. The results indicate that R. tanezumi populations from Yunnan have highest genetic diversity and populations from Tibet with lowest genetic diversity. 18 populations can be divided into four clusters, the first cluster including populations from southwest Yunnan, the second including two populations of Tibet, the third for populations from middle and east of mainland China, and the forth for two populations from north Yunnan. Both microsatellite and mtDNA data reveal that the populations from coastal areas are closely related to populations from Yunnan, whereas populations from Tibet are closely related with populations from Sichuan.ConclusionsThe results suggest that early dispersal of R. tanezumi in mainland China depended on shipping transportation, with subsequent expansion from coastal areas into Central China occurring along the Yangzi River. Further, the linkages between populations in Tibet and Sichuan point to a modern era introduction via the Chuan-Zang highway, rather than along the Tea Horse Ancient Road.Electronic supplementary materialThe online version of this article (10.1186/s12863-019-0714-3) contains supplementary material, which is available to authorized users.

Genetic differentiation of geographic populations of Rattus tanezumi based on the mitochondrial Cytb gene

“…A negative D value indicated that there was a slight deleterious mutation in the purifying selection or separation of the R. tanezumi population, which may also be caused by population expansion [41,42]. Guo et al [21] performed Tajima's D and Fu & Li's tests on the D-loop and COI genes of 12 R. tanezumi populations and found recent demographic expansion of these populations, which was consistent with our findings. COI is a widely used DNA barcoding method that shows sufficient resolution and stability in biological species and is suitable for species identification.…”

“…tanezumi population, which may also be caused by population expansion [ 41 , 42 ]. Guo et al [ 21 ] performed Tajima’s D and Fu & Li’s tests on the D-loop and COI genes of 12 R . tanezumi populations and found recent demographic expansion of these populations, which was consistent with our findings.…”

“…For example, Zhao et al [20] demonstrated by sequencing the mitochondrial DNA of R. tanezumi that river barriers have almost no effect on the genetic pattern of this species. Guo et al [21] suggested that the early dispersal of R. tanezumi in mainland China was the result of shipping transportation, which led to the subsequent expansion from coastal areas into Central China along the around the Winter Olympics venues and comprehensive control technology research and application (2019YJ060).…”

“…tanezumi that river barriers have almost no effect on the genetic pattern of this species. Guo et al [ 21 ] suggested that the early dispersal of R . tanezumi in mainland China was the result of shipping transportation, which led to the subsequent expansion from coastal areas into Central China along the Yangzi River.…”

Distribution and Host Selection of Tropical Rat Mite, Ornithonyssus bacoti, in Yunnan Province of Southwest China

“…Rattus tanezumi (often called R. flavipectus in China) is widely distributed in the vast areas south of the Yangtze River, in Southern China. It is a very common rodent species in residential areas (especially the indoor habitats) in Central and Southern Yunnan [ 54 , 55 ]. Rattus norvegicus is widely distributed in the whole China, and it is also a very common rodent species in residential areas (especially the indoor habitats) in Yunnan, often co-occurring in the same areas with R. tanezumi [ 35 , 56 , 57 , 58 ].…”