Bo-Mi Kima,†, Seunghyun Kanga,†, Do-Hwan Ahna,†, Seung-Hyun Jungb,†, Hwanseok Rheec,†, Jong Su Yoob, Jong-Eun Leec, SeungJae Leec, Yong-Hee Hand, Kyoung-Bin Ryud, Sung-Jin Chod,*, Hyun Parka,e,*, Hye Suck Anb,*
a Unit of Polar Genomics, Korea Polar Research Institute(KOPRI), Incheon 21990, Korea
b Department of Genetic Resources Research, National Marine Biodiversity Institute of Korea (MABIK), Janghang-eup, Seochun-gun, Chungchungnam-do 33662, Korea
c Genomics Lab, Cluster Center, DNA Link, Inc., 150, Bugahyeon-ro, Seodaemungu, Seoul 03759, Korea
d School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk 28644, Korea
e Polar Sciences, University of Science & Technology, Yuseong-gu, Daejeon 34113, Korea
*Co-corresponding author:
School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (S. Cho)
Unit of Polar Genomics, Korea Polar Research Institute, Incheon 21990, Korea; (H. Park)
Department of Genetic Resources Research, National Marine Biodiversity Institute of Korea (MABIK), Janghang-eup, Seochun-gun, Chungchungnam-do 33662, Korea; (H.S. An)
†These authors contributed equally to this work
Abstract
Background
The common long-arm octopus (Octopus minor) is found in mudflats of subtidal zones and faces numerous environmental challenges. The ability to adapt its morphology and behavioural repertoire to diverse environmental conditions makes the species a promising model to understand genomic adaptation and evolution in cephalopods.
Findings
The final genome assembly of O. minor is 5.09 Gb, with a contig N50 size of 197 kb and longest size of 3.027 Mb, from a total of 419 Gb raw reads generated using PacBio RS II platform. We identified 30,010 genes and 44.43% of the genome is composed of repeat elements. The genome-wide phylogenetic tree indicated the divergence time between O. minor and O. bimaculoides was estimated to be 43 million years ago (Mya) based on single-copy orthologous genes. In total, 178 gene families are expanded in O. minor in the 14 bilaterian species.
Conclusion
We found that the O. minor genome was larger than that of closely related O. bimaculoides, and this difference could be explained by enlarged introns and recently diversified transposable elements. The high-quality O. minor genome assembly provides a valuable resource for understanding octopus genome evolution and the molecular basis of adaptations to mudflats.