Introduction & Objective: Survivin is one of the new characterized members of the inhibitor of apoptosis proteins that shows widespread expression in embryonic and tumoric tissues. The aim of this study was to evaluate the expression of Survivin variants in different stages of follicular development in mouse ovary.

Materials & Methods: This experimental study was carried out on immature female mice (NMRI). Preantral, large preantral and antral follicles were mechanically isolated from ovaries from 12, 16 and 21-day old mice respectively. Total RNA from all above mentioned groups was extracted and cDNA synthesis was done using oligo dt primers and M-MuLV enzyme. PCR amplification of the cDNA samples was done using specific Survivin primers. The semi-quantitative expression of Survivin mRNA in cDNA samples were compared with that of β2m as an internal control, using post-hoc LSD test.

Results: Data showed the expression of two Survivin variants (140, 40) in different stages of follicles. The maximum expression of Survivin140 was observed in the preantral follicles and decreased towards antral stage (P<0.05). The level of Survivin 40 did not change significantly in three stages of follicles. The third variant, Survivin 121 mRNA was not expressed in any of follicular stages examined here. Conclusion: Since the highest level of apoptosis is detected in antral follicles, the lowest levels of Survivin140 mRNA in this stage might be related to a possible role in follicular atresia. Further studies at protein level are needed to confirm this role for Survivin 140 in ovarian follicles.