Transition protein 1 mRNA expression is not related to pregnancy rate in azoospermic men undergoing TESE-ICSI.

Our laboratory has previously reported significantly low levels of protamine (PRM) gene expression in infertile men. This drop was correlated with a low pregnancy rate, suggesting that PRMs may be useful as predictive factors for the outcome of testicular sperm extraction and intracytoplasmic sperm injection (TESE-ICSI) in azoospermic men. Transition nuclear proteins (TPs) are expressed earlier in spermatogenesis than protamines and are required for normal sperm development. In the present study, we examined the expression of the transition nuclear protein 1 gene (TNP1) in azoospermia and its relationship with TESE-ICSI outcomes. The cellular expression of TNP1 mRNA in spermatids was quantified by in situ hybridisation on paraffin sections of testis biopsies from 21 men with obstructive azoospermia and 23 men with non-obstructive azoospermia. Cases of non-obstructive and obstructive azoospermia. did not differ significantly in terms of TNP1 expression. Furthermore, TNP1 mRNA expression was similar in non-pregnant and pregnant couples. Hence, the pregnancy rate was not related to TNP1 mRNA expression levels in azoospermia. Our results emphasise the value of TNP1 as a reliable predictive marker for the presence of spermatids/spermatozoa in the testis biopsies used for TESE but also indicate that expression of the TNP1 gene (believed to be a major player in spermiogenesis and required for production of normal sperm) may not be a predictive factor for successful post-ICSI embryonic development.