Phenotypic changes in germ cells during gonadal development of the common carp (Cyprinus carpio). An immunohistochemical study with anti-carp spermatogonia monoclonal antibodies.

A procedure is described in which large early spermatogonia were isolated from carp testes and purified from an initial 45% recovery up to 60-70% using equilibrium density centrifugation on a continuous Percoll gradient. Mice were immunized with the spermatogonia via the intrasplenic route. Six hybridoma cultures, producing monoclonal antibodies (MAbs) reacting selectively with germ cells, were selected and further analysed. Reactivity with five of these MAbs was observed on primordial germ cells (PGCs) in the developing indifferent gonads at the onset of proliferation, i.e. the age of 7 weeks