EXTRACELLULAR-MATRIX ABNORMALITIES IN TESTIS AND EPIDIDYMIS OF XXSXR (SEX-REVERSED) MICE

Sex-reversed (Sxr) is a duplication of the sex-determining region of t he Y chromosome, which gets transposed to a paternal X chromosome. Chr omosomally female (XX) zygotes that receive this XSxr chromosome devel op as apparent males. Previous work on XXSxr mice (called pseudomales) showed extracellular matrix (ECM) ultrastructural abnormalities in th e epididymis and testis. This study examined the biochemical nature of these abnormalities. More hydroxyproline (an indicator of collagen) w as noted in the pseudomale testis and epididymis compared to normal ma le tissues. Western blot analysis showed increased collagen IV in the pseudomale testis and epididymis. In both the hydroxyproline and colla gen IV studies, the epididymis was found to contain higher levels of t hese substances than the testis for both genotypes. There also appeare d to be increased messenger RNA for tissue inhibitor of metalloprotein ases (Timp), a regulator of collagen, in the pseudomale testis. Data f rom these studies seem to indicate that the XXSxr genotype influences ECM deposition and/or turnover and exerts a direct genetic influence o n the development of the testis and epididymis. According to the exist ing paradigm of mammalian sexual development, the epididymis is expect ed to be normal in the presence of adequate androgenization and indepe ndent of chromosomal and genetic sex. The results presented here diffe r from what would be predicted by this paradigm. (C) 1994 Wiley-Liss, Inc.