Aquaporins (AQPs) are a well-conserved family of small (approximately 30 kDa) membrane channel proteins that facilitate rapid movement of fluids and have a unique tissue-specific pattern of expression. These proteins have been found in the female reproductive systems of humans, rats, and mice. However, the expression and cellular localization of AQPs have not extensively been studied in the female reproductive system of sheep. Therefore, this study aimed to evaluate, by real-time polymerase chain reaction and immunohistochemistry respectively, the levels of messenger RNA and the immunolocalization of AQP3, AQP7, and AQP9 in large isolated ovine secondary follicles over a period of IVC. Our analysis revealed that AQP3 and AQP9 were present predominately in follicles that exhibited antrum formation, suggesting a crucial role of these AQPs in the formation of the antrum. Interestingly, AQP7 was only expressed in follicles that had not formed an antrum by Day 12 of culture. In conclusion, the presence of protein channels (AQP3 and AQP9) seems to be essential for the formation of the antrum in isolated ovine secondary follicles cultured in vitro and thus plays an important role during folliculogenesis in this species.

This study aimed to compare several DNA polymerases in order to optimize costs of microsatellite amplification reaction through the PowerPlex®16 BIO System. Three different polymerase brands have been used: (i) Paq5000 DNA Polymerase (Stratagene) and (ii) Platinum® Taq DNA Polymerase (Invitrogen), which have low commercial price; and (iii) Advantage 2 Polymerase Mix (Clontech), a DNA polymerase with high commercial price. Herein, neither samples nor positive control amplified in the reactions carried out with Paq5000 DNA Polymerase. Furthermore, the reactions performed with Platinum® Taq DNA Polymerase showed contrasting results, amplifying alleles only in some samples. On the other hand, the two microsatellite loci used (amelogenin e D18S51) were amplified in the analyses carried out with the Advantage 2 Polymerase Mix. Our findings indicated that the enzymes Paq5000 DNA Polymerase and Platinum® Taq DNA Polymerase have low processing capacity, showing inefficiency in the microsatellite detection; and that Advantage 2 Polymerase Mix is highly effective and suitable for microsatellite amplification assays.