A female-specific cDNA sequence ofSchistosoma mansoniencoding a mucin-like protein that is expressed in the epithelial cells of the reproductive duct

Abstract

SUMMARYSeven cDN A clones ofSchistosoma mansonicontaining the C-terminal part of the deduced sequence of a mucin-like protein have been identified. The protein contains 28% threonines, 20% serines, and has a pi of 3middot;4. On Northern blots of RNA of adult worms, the cDNA clones detect 2 transcripts of 1middot;65 and 4middot;2 kb which are expressed only in female worms. The tissue of gene expression, as revealed byin situhybridization, is the epithelium surrounding the female reproduction duct proximal to its entrance into the ootype. Accumulation of N-glycosylation sites suggests that the protein, like other mucins, might form a protective layer, coating the lining of the duct. Regarding its acidic pi, we hypothesize a role in preventing premature egg-shell formation. This is the first female-specifically transcribed sequence, hitherto known inS.mansonithat is not expressed in the vitellaria.