Comparative phylogeography of two commensal rat species (Rattus tanezumi and Rattus norvegicus) in China: Insights from mitochondrial DNA, microsatellite, and 2b‐RAD data

Abstract

Rattus norvegicus and Rattus tanezumi are dominant species of Chinese house rats, but the colonization and demographic history of two species in China have not been thoroughly explored. Phylogenetic analyses with mitochondrial DNA including 486 individuals from 31 localities revealed that R. norvegicus is widely distributed in China, R. tanezumi is mainly distributed in southern China with currently invading northward; northeast China was the natal region of R. norvegicus , while the spread of R. tanezumi in China most likely started from the southeast coast. A total of 123 individuals from 18 localities were subjected to 2b‐RAD analyses. In neighbor‐joining tree, individuals of R. tanezumi grouped into geographic‐specific branches, and populations from southeast coast were ancestral groups, which confirmed the colonization route from southeast coast to central and western China. However, individuals of R. norvegicus were generally grouped into two clusters instead of geographic‐specific branches. One cluster comprised inland populations, and another cluster included both southeast coast and inland populations, which indicated that spread history of R. norvegicus in China was complex; in addition to on‐land colonization, shipping transportation also have played great roles. ADMIXTURE and principal component analyses provided further supports for the colonization history. Demographic analyses revealed that climate changes at ~40,000 to 18,000 years ago and ~4000 years ago had led to population declines of both species; the R. norvegicus declined rapidly while the population of R. tanezumi continuously expanded since ~1500 years ago, indicating the importance of interspecies' competition in their population size changes. Our study provided a valuable framework for further investigation on phylogeography of two species in China.

Genomic and Phenotypic Adaptations of Rattus tanezumi to Cold Limit Its Further Northward Expansion and Range Overlap with R. norvegicus

“…Moreover, the extensive construction of roads and bridges in recent decades likely facilitated the spread of commensal rats in China, as human-assisted dispersal can overcome environmental barriers ( Combs et al 2018 ). We observed that the CD samples displayed admixture of the South and Tibetan populations, which could be attributed to the Chuan-Zang highway linking Tibetan and Central China, which starts in CD and extends to Lhasa in Tibet ( Guo et al 2019 ; Jing et al 2022 ).…”

“…It is the latest to undergo range expansion or invasion among the three species ( Bastos et al 2011 ; Lack et al 2012 ; Conroy et al 2013 ; Guo et al 2019 ; Liu et al 2021 ; Chen et al 2021a ). In the past 40 years, RT rats in southern China (below 30°N) have rapidly colonized regions below 40°N in the north, northwest, and Tibetan Plateau areas in China ( Shou 1962 ; Wilson and Reeder 2005 ; Guo et al 2019 ; Liu et al 2021 ; Chen et al 2021a ; Jing et al 2022 ). The recently introduced RT rats have partially replaced local RN rats due to their superior interspecific interference and high resistance to rodenticides, which has led them to outcompete RN rats ( Teng et al 2016 ; Guo et al 2017 ; Chen et al 2021a ).…”

Human Population Density Influences Genetic Diversity of Two Rattus Species Worldwide: A Macrogenetic Approach

“…The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/genes14071442/s1, Table S1: Systematic review-final studies included [6,[19][20][21][28][29][30][31][35][36][37][38][39][41][42][43][44][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65].…”