Localization of egg-laying hormone in the gonads of a tropical abalone, Haliotis asinina linnaeus

Abstract

Connective tissue frameworks of the gonad of H.asinina consist of the outer gonadal capsule, flat sheets of connective tissue, called trabeculae, that extend from the former toward the inner capsules separating the gonad from the hepatopancreas. Trabeculae, thus, partition the gonad into compartments; and each trabecula acts as the axis on which growing germ cells are attached and proliferate. Each trabecula contains small capillaries in the center, surrounded by muscle cells, collagen fibers intermingled with fibroblasts, and a substantial number of granulated cells that branch extensively. Localization of abalone egg-laying hormone (aELH) was performed by immunoperoxidase technique using polyvalent antibody against recombinant aELH as a probe. Anti-aELH exhibited strong bindings, which implied the presence of aELH, to muscle cells and granulated cells within trabeculae and capsules of both male and female gonads. The cytoplasm of immature oocytes (stages 1, 2, 3) were moderately stained, while that of mature oocytes (stages 4, 5) were only weakly stained. In contrast, male germ cells were not stained.