Expression of transforming growth factor-β isoforms and their receptors in utero-vaginal junction of hen oviduct in presence or absence of resident sperm with reference to sperm storage

Abstract

Our goal was to determine whether transforming growth factor β (TGFβ) isoforms were involved in the process of sperm survivability in the sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) of hen oviduct. The birds were artificially inseminated. The mRNA expressions of three types of TGFβ isoforms (TGFβ2, TGFβ3, and TGFβ4) and three types of receptors (TβR1, TβR2, and TβR3) were examined in the presence or in the absence of resident sperm in SST by semi-quantitative reverse transcriptase-PCR. The mRNA expression of TGFβs and TβRs in sperm was also examined. Immunocytochemistry and western blot were performed for TβR2 to confirm its localization in UVJ. The sperm were observed at least 10 days after insemination by histology. The mRNA expressions of TGFβs and TβRs were significantly increased in UVJ in the presence of resident sperm in SST. The mRNA expressions of TGFβs and TβRs were also observed in sperm. Immunohistochemistry revealed that TβR2 were located in lymphocytes in UVJ and SST cells. The presence of TβR2 in UVJ was also confirmed by western blot. These results suggest that enhanced expressions of TGFβs and TβRs in UVJ may protect sperm in SST, probably by suppressing anti-sperm immunoreactions.