Quantitative and Qualitative Expression Analysis of the Progesterone Receptor Membrane Component 1 (PGMRC1) in the Tissues of Female Half-Smooth Tongue Sole (Cynoglossus semilaevis)

Abstract:

Progesterone receptor membrane component 1 (PGRMC1) may play an important role in oocyte maturation of the female half-smooth tongue sole (Cynoglossus semilaevis). To better understand the underlying mechanisms, here we measured the mRNA expression of PGRMC1 in different tissues with in situ RNA hybridization and immunohistochemistry, and analyzed the protein expression with western blotting. According to the results of in situ RNA hybridization, the mRNA of PGRMC1 was detected in the membrane of oocytes, in scattered cells of the entire pituitary, and in the neurons of the brain. Immunohistochemistry showed strong signals of PGRMC1 in the oocyte membrane of the mature ovary, and signals were also observed in the liver, kidney, and head kidney of C. semilaevis. In the liver, PGRMC1 was mainly expressed in the bile duct and hepatic veins that were connected to the outer tissue. In the kidney, the PGRMC1 was expressed in the vicinity of the renal tubules. The results above demonstrated that PGRMC1 was a membrane receptor that functioned on the cell membrane. We also analyzed the protein sequence of PGRMC1, selected epitope of the sequence, and synthesized the corresponding immune polypeptide. We obtained the polyclonal antibody of PGRMC1 by immunizing New Zealand rabbit with the recombinant protein. The antibody was applied to measure the expression level of PGRMC1. Western blotting results showed that the expression of PGRMC1 protein was higher in the ovary, liver, and brain, and was relatively low in the kidney, head kidney, and pituitary. Our results may provide valuable information on the physiological function of PGRMC1 in the oocyte maturation and reproductive endocrinal regulation of C. semilaevis