Journal Article

Population genomics of finless porpoises reveal an incipient cetacean species adapted to freshwater

Li, Mingzhou, Seim, Inge, Xu, Shixia, Xu, Jiabao, Li, Shuaicheng, Sun, Di, Jie, Wencai, Chen, Bingyao, Guang, Xuanmin, Gladyshev, Vadim N., Kaya, Alaattin, Yang, Linfeng, Zhu, Qianhua, Fang, Xiaodong, Yang, Guang, Ren, Wenhua, Gao, Qiang, Dou, Qianhui, Zhou, Kaiya, Nielsen, Rasmus, Zhou, Xuming

2018

Overview

Cetaceans (whales, dolphins, and porpoises) are a group of mammals adapted to various aquatic habitats, from oceans to freshwater rivers. We report the sequencing, de novo assembly and analysis of a finless porpoise genome, and the re-sequencing of an additional 48 finless porpoise individuals. We use these data to reconstruct the demographic history of finless porpoises from their origin to the occupation into the Yangtze River. Analyses of selection between marine and freshwater porpoises identify genes associated with renal water homeostasis and urea cycle, such as urea transporter 2 and angiotensin I-converting enzyme 2, which are likely adaptations associated with the difference in osmotic stress between ocean and rivers. Our results strongly suggest that the critically endangered Yangtze finless porpoises are reproductively isolated from other porpoise populations and harbor unique genetic adaptations, supporting that they should be considered a unique incipient species. Whales, dolphins and porpoises are adapted to various aquatic habitats. Here, Zhou et al. show that polymorphisms associated with renal function and the urea cycle have undergone selection in the freshwater Yangtze finless porpoise and provide genomic evidence of incipient speciation.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 45/22 / 45/23 / 45/77 / 631/181/2474 / 631/181/457 / 631/181/759 / 631/601 / Adaptation / Adaptation, Biological / Angiotensin / Angiotensin I / Animals / Aquatic habitats / Aquatic mammals / Biological Evolution / Biology / Cetacea / China / Chromosome Mapping / Coasts / Demographics / Dolphins / Dolphins & porpoises / Endangered & extinct species / Endangered species / Gene sequencing / Genome / Genomes / Genomics / Haplotypes / Harbors / Homeostasis / Humanities and Social Sciences / Hypotheses / Laboratories / Life sciences / Marine mammals / Metagenomics / multidisciplinary / Oceans / Osmotic stress / Peptidyl-dipeptidase A / Phylogenetics / Phylogeny / Population / Population genetics / Porpoises / Porpoises - classification / Porpoises - genetics / Principal components analysis / Reproductive Isolation / Rivers / Science / Science (multidisciplinary) / Seawater / Urea / Water-Electrolyte Balance