Author(s): VARELA, E. S.; BEKAERT, M.; KIRSCHNIK, L. N. G.; TORATI, L. S.; SHIOTSUKI, L.; O'SULLIVAN, F. L. A.; VILLELA, L. C. V.; REZENDE, F. P.; BARROSO, A. da S.; FREITAS, L. E. L. de; TAGGART, J. B.; MIGAUD, H.

Summary: Tambaqui (Colossoma macropomum, Cuvier, 1818) is the most economically important native freshwater fish species in Brazil. It can reach a total length of over 1 m and a weight of over 40 kg. The species displays a clear sex dimorphism in growth performance, with females reaching larger sizes at harvest. In aquaculture, the production of monosex populations in selective breeding programmes has been therefore identified as a key priority. In the present study, a genetic linkage map was generated by double digest restriction-site associated DNA (ddRAD) sequencing from 248 individuals sampled from two F1 families. The map was constructed using 14,805 informative SNPs and spanned 27 linkage groups. From this, the tambaqui draft genome was improved, by ordering the scaffolds into chromosomes, and sex-linked markers were identified. A total of 235 markers on linkage group 26 showed a significant association with the phenotypic sex, supporting an XX/XY sex determination system in the species. The four most informative sex-linked markers were validated on another 206 sexed individuals, demonstrating an accuracy in predicting sex ranging from 90.0 to 96.7%.

Publication year: 2021

Types of publication: Journal article

Unit: Embrapa Fisheries and Aquaculture

Keywords: Aquaculture, Aquicultura, Colossoma Macropomum, Fish, Genetic markers, Linkage map, Monosex, Peixe, Sex determination, Sex-linked markers, Tambaqui