Narwhal Genome Reveals Long-Term Low Genetic Diversity despite Current Large Abundance Size

• Main Authors: Michael V. Westbury, Bent Petersen, Eva Garde, Mads Peter Heide-Jørgensen, Eline D. Lorenzen
• Format: Article
• Language: English
• Published: Elsevier 2019-05-01
• Series: iScience
• Online Access: http://www.sciencedirect.com/science/article/pii/S2589004219300896

Summary: The narwhal (Monodon monoceros) is a highly specialized endemic Arctic cetacean, restricted to the Arctic seas bordering the North Atlantic. Low levels of genetic diversity have been observed across several narwhal populations using mitochondrial DNA and microsatellites. Despite this, the global abundance of narwhals was recently estimated at ∼170,000 individuals. However, the species is still considered vulnerable to changing climates due to its high specialization and restricted Arctic distribution. We assembled and annotated a genome from a narwhal from West Greenland. We find relatively low diversity at the genomic scale and show that this did not arise by recent inbreeding, but rather has been stable over an extended evolutionary timescale. We also find that the current large global abundance most likely reflects a recent rapid expansion from a much smaller founding population. : Biological Sciences; Genetics; Evolutionary Biology Subject Areas: Biological Sciences, Genetics, Evolutionary Biology