Isolation of a female-specific, highly repeated Schistosoma mansoni DNA probe and its use in an assay of cercarial sex.

A 476 bp fragment of female-specific Schistosoma mansoni genomic DNA, clone W1, represents a degenerative repeat present in more than 500 copies per female genome, and may be part of the constitutive heterochromatin of the W chromosome. The cloning method described can be used as a general approach for isolating sex-specific, repeated DNA fragments. Using W1 as a probe, we have developed a rapid and accurate dot-blot assay for determining the sex of S. mansoni cercariae.