Screening and identification of potential sex‐associated sequences in Danio rerio

SUMMARY Current knowledge on zebrafish ( Danio rerio ) suggests that sex determination has a polygenic genetic basis in this species, although environmental factors may also be involved. This study aimed to identify sex‐associated genomic regions using two different marker systems: inter‐simple sequence repeats (ISSRs) and random‐amplified polymorphic DNA (RAPDs). Two bulks were constructed: one with DNA from zebrafish females and the other from males; then, a total of 100 ISSR and 280 RAPD primers were tested. Three DNA fragments presenting sexual dimorphism (female‐linked: OPA17 436 and OPQ19 1027 ; male‐linked: OPQ19 951 ) were determined from sequential analysis of the bulks followed by assessment in individuals. These fragments were cloned and convert into the following sequenced characterized amplified regions (SCAR): DrSM_F1, DrSM_F2, and DrSM_M, which share identities with sequences located in chromosomes 2, 3, and 11 (Zv9), respectively. Using these potential markers in zebrafish samples it was possible to correctly identify 80% of the males (DrSM_M) and 100% of the females (DrSM_F1 + DrSM_F2) in the analyzed population. Mol. Reprod. Dev. 82: 756–764, 2015. © 2015 Wiley Periodicals, Inc .