RT Journal Article
SR Electronic
T1 A Chromosome-level Assembly of the Japanese Eel Genome, Insights into Gene Duplication and Chromosomal Reorganization
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.06.28.497880
DO 10.1101/2022.06.28.497880
A1 Hongbo Wang
A1 Hin Ting Wan
A1 Bin Wu
A1 Jianbo Jian
A1 Alice HM Ng
A1 Claire Yik-Lok Chung
A1 Eugene Yui-Ching Chow
A1 Jizhou Zhang
A1 Anderson OL Wong
A1 Keng Po Lai
A1 Ting Fung Chan
A1 Eric Lu Zhang
A1 Chris Kong-Chu Wong
YR 2022
UL http://biorxiv.org/content/early/2022/07/01/2022.06.28.497880.abstract
AB Japanese eels (Anguilla japonica) are commercially important species that have been harvested extensively for foods. Currently, this and related species (American and European eels) are difficult to breed on a commercial basis. Wild stock is used for aquaculture. Due to pollution, overfishing, and international trafficking, eel populations are declining. The International Union for Conservation of Nature lists Japanese eels as critically endangered and on its red list. Here we presented a high-quality genome assembly for Japanese eels and demonstrated that large chromosome reorganizations occurred in the events of third-round whole-genome duplications (3R-WRD). Following multiple chromosomal fusion and fission rearrangement, the Anguilla lineage has reduced the haploid chromosomal number of 19 from the ancestral proto-chromosomal number of 25. Phylogenetic analysis of expanded gene families showed the gene families of olfactory receptors and voltage-gated Ca2+-channel expanded significantly. The expansion of olfactory receptors (group δ and ζ genes) and voltage-gated Ca2+-channel gene families are important for olfaction and neurophysiological functions. Following 3R-WGD, additional tandem (TD) and proximal (PD) duplications occurred to acquire immune-related genes for adaptation. The Japanese eel assembly presented here can be used to study other Anguilla species that are related to evolution and conservation.Competing Interest StatementThe authors have declared no competing interest.