Immunochemical Detection, Estrogen Induction and Occurrence in Serum of Vitelline Envelope-Related Proteins of Sakhalin Taimen Hucho perryi

Abstract

Vitelline envelope-Related proteins (VERPs) were immunologically detected in serum and liver of female Sakhalin taimen Hucho perryi, but not in males, using an antiserum against vitelline envelope. Two VERPs were observed in serum as female-specific proteins with molecular weights of 48 kDa and 42 kDa on SDS-PAGE under non-reduced conditions. VERPs were induced in serum and the liver of immature fish by injection of 10 μg estradiol-17β (E₂) per kg of body weight. These results suggest that the origin of VERPs is the liver. During vitellogenesis, one VERP band first appeared in July in the serum of five-year-old fish. Two VERP bands were observed during winter and became undetectable in June after ovulation. The changes in VERPs were parallel to those in vitellogenin.