摘要：SummaryThe barred knifejaw,Oplegnathus fasciatus, is characterized by an X1X2Y system with a neo-Y chromosome for males. Here, a chromosome-level genome was assembled to investigate the origin of neo-Y chromosome to the maleO. fasciatus. Twenty-three chromosomes corresponding to the male karyotypes were scaffolded to 762-Mb genome with a contig N50 length of 2.18 Mb. A large neo-Y chromosome (Ch9) in the maleO. fasciatusgenome was also assembled and exhibited high identity to those of the female chromosomesCh8andCh10. Chromosome rearrangements events were detected in the neo-chromosomeCh9. Our results suggested that a centric fusion of acrocentric chromosomesCh8andCh10should be responsible for the formation of the X1X2Y system. The high-quality genome will not only provide a solid foundation for further sex-determining mechanism research in the X1X2Y system but also facilitate the artificial breeding aiming to improve the yield and disease resistance forOplegnathus.Graphical AbstractDisplay OmittedHighlights•Construction of a chromosome-level reference genome for the maleO. fasciatus•Identification of the origin of neo-Y chromosome to the X1X2Y system•Accurate comparisons of sequences and genes between female X1X1X2X2and male X1X2YMarine Organism; Biological Sciences; Genetics; Genomics; Evolutionary Biology
