Fatty acid metabolism decreased while sexual selection increased in brown rats spreading south
Yao-Hua Zhang,
Lei Zhao,
Ming-Yu Zhang,
Rui-Dong Cao,
Guan-Mei Hou,
Hua-Jing Teng,
Jian-Xu Zhang
Affiliations
Yao-Hua Zhang
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China; Corresponding author
Lei Zhao
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
Ming-Yu Zhang
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
Rui-Dong Cao
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
Guan-Mei Hou
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
Hua-Jing Teng
Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
Jian-Xu Zhang
State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China; Corresponding author
Summary: For mammals that originate in the cold north, adapting to warmer environments is crucial for southwards invasion. The brown rat (Rattus norvegicus) originated in Northeast China and has become a global pest. R. n. humiliatus (RNH) spread from the northeast, where R. n. caraco (RNC) lives, to North China and diverged to form a subspecies. Genomic analyses revealed that subspecies differentiation was promoted by temperature but impeded by gene flow and that genes related to fatty acid metabolism were under the strongest selection. Transcriptome analyses revealed downregulated hepatic genes related to fatty acid metabolism and upregulated those related to pheromones in RNH vs. RNC. Similar patterns were observed in relation to cold/warm acclimation. RNH preferred mates with stronger pheromone signals intra-populationally and more genetic divergence inter-populationally. We concluded that RNH experienced reduced fat utilization and increased pheromone-mediated sexual selection during its invasion from the cold north to warm south.
