The enormous repetitive Antarctic krill genome reveals environmental adaptations and population insights

• DOI: 10.1016/j.cell.2023.02.005
• Publication Date: 2023-03-02T15:30:46Z
• Authors: Changwei Shao; Shuai Sun; Kaiqiang Liu; Jiahao Wang; Shuo Li; Qun Liu; Bruce E. Deagle; Inge Seim; Alberto Biscontin; Qian Wang; Xin Liu; So Kawaguchi; Yalin Liu; Simon Jarman; Yue Wang; Hong-Yan Wang; Guodong Huang; Jiang Hu; Bo Feng; Cristiano De Pittà; Shanshan Liu; Rui Wang; Kailong Ma; Yiping Ying; Gabrielle Sales; Tao Sun; Xinliang Wang; Yaolei Zhang; Yunxia Zhao; Shanshan Pan; Xiancai Hao; Yang Wang; Jiakun Xu; Bowen Yue; Yanxu Sun; He Zhang; Mengyang Xu; Yuyan Liu; Xiaodong Jia; Jiancheng Zhu; Shufang Liu; Jue Ruan; Guojie Zhang; Huanming Yang; Xun Xu; Jun Wang; Xianyong Zhao; Bettina Meyer; Guangyi Fan
• Keywords: Antarctic krill; Euphausiacea

Antarctic krill (Euphausia superba) is Earth’s most abundant wild animal, and its enormous biomass vital to the Southern Ocean ecosystem. Here, we report a 48.01-Gb chromosome-level genome, whose large genome size appears have resulted from inter-genic transposable element expansions. Our assembly reveals molecular architecture of circadian clock uncovers expanded gene families associated with molting energy metabolism, providing insights into adaptations cold highly seasonal environment. Population-level re-sequencing four geographical sites around continent no clear population structure but highlights natural selection environmental variables. An apparent drastic reduction in 10 mya subsequent rebound 100 thousand years ago coincides climate change events. findings uncover genomic basis provide valuable resources for future research.