Occurrence of freemartinism in Santa Ines sheep

Résumé

This study reports a case of freemartinism of the XX/XY chimera type in a Santa Ines sheep belonging to a property in northeastern Para, Brazil. Discrete masculinization and external genitalia presenting a pseudoprepuce with a hypoplastic penis were observed in vivo. Anatomopathological examination of the internal genitalia showed the absence of a cervix and bilateral presence of an ovary and testis. Variable degrees of epididymal development, accompanied by agenesis of the deferent ducts and other structures arising from the mesonephric ducts, were also observed. Follicular structures, a uterine tubular portion, with marked agenesis and aplasia of the uterine tubes and in some portions of the horns, as well as other parts of paramesonephric structures, were noted in the ovaries. Blood was collected for karyotype analysis and 10 metaphases obtained by short-term lymphocyte culture were examined. Two cell lines were identified: 54,XX (5 cells) and 54,XY (5 cells). Key words: Freemartin, XX/XY chimerism, sheep, Santa Ines.