Figure 1.

Southern blot of EcoRI-digested male and female DNA with a human DMRT1 cDNA (a), and rehybridized with medaka genomic DMRT1 (b) and DMRT1Y (c) probes. DMRT1 and DMRT1Y show some cross-hybridization to each other even under conditions of highest stringency because of the high sequence similarity. The hybridization conditions in a were moderate stringency and high stringency in b and c. (d and e) Hybridization under even further increased stringency conditions of PstI-digested DNAs. (f) PCR from DNA of female and male medakas (strain i-3) with DMRT1Y- and DMRT1-specific primers. Cosmid 9 contains the autosomal DMRT1 gene (26) and cosmid 13 contains DMRT1Y. (g) Genetic linkage map of the region flanking the male SD, based on meiosis in sex-reversed XY females. Numbers indicate genetic distances in centimorgans (cM). Markers DMRT1Y and SDY (locus determining the male sex phenotype) showed no recombination.