1
|
Nakamoto M, Uchino T, Koshimizu E, Kuchiishi Y, Sekiguchi R, Wang L, Sudo R, Endo M, Guiguen Y, Schartl M, Postlethwait JH, Sakamoto T. A Y-linked anti-Müllerian hormone type-II receptor is the sex-determining gene in ayu, Plecoglossus altivelis. PLoS Genet 2021; 17:e1009705. [PMID: 34437539 PMCID: PMC8389408 DOI: 10.1371/journal.pgen.1009705] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 07/09/2021] [Indexed: 11/19/2022] Open
Abstract
Whole-genome duplication and genome compaction are thought to have played important roles in teleost fish evolution. Ayu (or sweetfish), Plecoglossus altivelis, belongs to the superorder Stomiati, order Osmeriformes. Stomiati is phylogenetically classified as sister taxa of Neoteleostei. Thus, ayu holds an important position in the fish tree of life. Although ayu is economically important for the food industry and recreational fishing in Japan, few genomic resources are available for this species. To address this problem, we produced a draft genome sequence of ayu by whole-genome shotgun sequencing and constructed linkage maps using a genotyping-by-sequencing approach. Syntenic analyses of ayu and other teleost fish provided information about chromosomal rearrangements during the divergence of Stomiati, Protacanthopterygii and Neoteleostei. The size of the ayu genome indicates that genome compaction occurred after the divergence of the family Osmeridae. Ayu has an XX/XY sex-determination system for which we identified sex-associated loci by a genome-wide association study by genotyping-by-sequencing and whole-genome resequencing using wild populations. Genome-wide association mapping using wild ayu populations revealed three sex-linked scaffolds (total, 2.03 Mb). Comparison of whole-genome resequencing mapping coverage between males and females identified male-specific regions in sex-linked scaffolds. A duplicate copy of the anti-Müllerian hormone type-II receptor gene (amhr2bY) was found within these male-specific regions, distinct from the autosomal copy of amhr2. Expression of the Y-linked amhr2 gene was male-specific in sox9b-positive somatic cells surrounding germ cells in undifferentiated gonads, whereas autosomal amhr2 transcripts were detected in somatic cells in sexually undifferentiated gonads of both genetic males and females. Loss-of-function mutation for amhr2bY induced male to female sex reversal. Taken together with the known role of Amh and Amhr2 in sex differentiation, these results indicate that the paralog of amhr2 on the ayu Y chromosome determines genetic sex, and the male-specific amh-amhr2 pathway is critical for testicular differentiation in ayu.
Collapse
Affiliation(s)
- Masatoshi Nakamoto
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Tsubasa Uchino
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Eriko Koshimizu
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
- Department of Human Genetics, Yokohama City University, Graduate School of Medicine, Yokohama, Japan
| | - Yudai Kuchiishi
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Ryota Sekiguchi
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Liu Wang
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Ryusuke Sudo
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Masato Endo
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | | | - Manfred Schartl
- University of Wuerzburg, Developmental Biochemistry, Biocenter, Würzburg, Germany
- The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, United States of America
| | - John H. Postlethwait
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
| | - Takashi Sakamoto
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| |
Collapse
|