An AFLP-based approach for the identification of sex-linked markers in Amur sturgeon Acipenser schrenckii Brandt, 1869

Abstract

Sturgeon species are widely known for their caviars. A large part of the expense associated with caviar production is due to the length of time individuals must be reared before reaching maturity. Sex identification at an early age would reduce costs of broodstock rearing. A DNA AFLP-fingerprinting approach was used to identify sex-specific markers and sex-associated markers that exhibit a difference between female and male Amur sturgeon Acipenser schrenckii Brandt, 1869. AFLP analysis of six females and six males using 64 primer combinations yielded a total of 7116 AFLP bands of which 1264 (17.76%) bands were polymorphic. The polymorphism exhibited differences between female (15.64%) and male (16.34%) groups. Sex-specific markers were not detected among the AFLP bands. However, 42 presumed sex-associated bands that exhibited large differences between females and males were identified in 34 primer combinations. None of the 28 SCAR markers derived from the 39 sequences exhibited sex specificity when tested against 15 females and 15 males. Nevertheless, five SCAR markers exhibited a significant difference between the sexes. Sequence analysis using blastn in GenBank revealed high homology for 10 fragments, among which C4 was associated with the secretion of prolactin in mammals, but was not sex-specific based on testing of SCAR markers. The five SCAR markers and the clone C4 may represent candidate genes for future research of sex specificity.