ANDROGEN-BINDING PROTEIN IS TISSUE-SPECIFICALLY EXPRESSED AND BIOLOGICALLY-ACTIVE IN TRANSGENIC MICE

In view of the inconclusive data concerning the role of androgen-bindi ng protein (ABP) in male reproductive physiology, we thought it would be pertinent to make several transgenic mouse lines overexpressing the rat ABP gene to unravel its role in Sertoli cell and epididymal homeo stasis. Heterozygote transgenic mouse lines carrying the 5.5 kb ABP ra t genomic DNA were produced by pronuclear microinjection. Northern blo t analysis showed overexpression of rat ABP (rABP) mRNA in the testis of transgenic mice compared to rat testis control. rABP was appropriat ely expressed in Sertoli cells as demonstrated by in situ hybridizatio n analysis. Sertoli cell number is increased in the seminiferous tubul es of mice overexpressing rABP compared to non-transgenic littermates and scattered Sertoli cells present vacuolated-like cytoplasms, PAS an d osmium negative. Compared to the wild type, the transgenic mice exhi bited reduced fertility and focal damage in seminiferous epithelium ch aracterized by morphological features compatible with programmed cell death.