|Title||A duplicated copy of id2b is an unusual sex-determining candidate gene on the Y chromosome of arapaima (Arapaima gigas).|
|Publication Type||Journal Article|
|Year of Publication||2021|
|Authors||Adolfi, MC, Du, K, Kneitz, S, Cabau, C, Zahm, M, Klopp, C, Feron, R, Paixão, RV, Varela, ES, de Almeida, FL, de Oliveira, MA, Nóbrega, RH, Lopez-Roques, C, Iampietro, C, Lluch, J, Kloas, W, Wuertz, S, Schaefer, F, Stöck, M, Guiguen, Y, Schartl, M|
|Date Published||2021 Nov 03|
Arapaima gigas is one of the largest freshwater fish species of high ecological and economic importance. Overfishing and habitat destruction are severe threats to the remaining wild populations. By incorporating a chromosomal Hi-C contact map, we improved the arapaima genome assembly to chromosome-level, revealing an unexpected high degree of chromosome rearrangements during evolution of the bonytongues (Osteoglossiformes). Combining this new assembly with pool-sequencing of male and female genomes, we identified id2bbY, a duplicated copy of the inhibitor of DNA binding 2b (id2b) gene on the Y chromosome as candidate male sex-determining gene. A PCR-test for id2bbY was developed, demonstrating that this gene is a reliable male-specific marker for genotyping. Expression analyses showed that this gene is expressed in juvenile male gonads. Its paralog, id2ba, exhibits a male-biased expression in immature gonads. Transcriptome analyses and protein structure predictions confirm id2bbY as a prime candidate for the master sex-determiner. Acting through the TGFβ signaling pathway, id2bbY from arapaima would provide the first evidence for a link of this family of transcriptional regulators to sex determination. Our study broadens our current understanding about the evolution of sex determination genetic networks and provide a tool for improving arapaima aquaculture for commercial and conservation purposes.
|Alternate Journal||Sci Rep|
|PubMed Central ID||PMC8566520|