Microsatellite mapping of the prolactin locus in the tilapia genome.

Materials and methods: Genomic DNA was isolated from whole blood. Enzyme-digested DNA samples were resolved in 1% agaroseTBE gels for Southern transfer. The cDNA probe insert was purified from a low-melting-point agarose gel made with TAE buffer and was radioactively labelled with [a-^^P]dCTP using the random primers method. Prehybridization of filters was carried out at 60°C in 5x SSPE, 0 5% SDS, 01 mg ml"^ herring sperm DNA and 5x Denhardt's reagent; for hybridization, the same conditions were used, but without the Denhardt's reagent. The final stringency of washing was in lx SSC, 60°C. The exposure time for autoradiography was 1—6 days.