The Bkm satellite marker was first found in the Banded Krait, Bungarus fasciatus, and found in abundance on the female sex chromosome (Wachtel et al., 1991).This DNA microsatellite is also found in other vertebrates including fish, amphibians, reptiles, mammals and birds; as well as insects and echinoderms (Shapiro, 1988). From this abundance of examples of heterogametic organisms, it is quite possible that the Bkm DNA may have a role in sex-change in fish.
In an unpublished experiment (Okubo, Tracey, Leon, Pechan and Shapiro, but see Shapiro, 1988 for details), males of the protogynous Anthias squamipinnis (Serranidae) were found to have Bkm DNA, while they were completely absent from females. Such evidence further supports the possible role of Bkm DNA in sex-change. However, an experiment by Wachtel et al. (1991), there was no evidence of male-specific Bkm hybridization. Further work may provide some conclusions as to the involvement of the Bkm satellite DNA in the process of sex-change in fish.
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