Nuclear transplantation in teleost Misgurnus fossilis L.

Abstract

ALTHOUGH the transplantation of somatic cell nuclei into eggs has been achieved in amphibian species^1,2, Drosophila³ and some mammals^4,5, it is important to use further groups of animals because experience with amphibia has shown that the subsequent development of normal animals depends largely on the species used. We report here successful transplantation of nuclei from middle or late blastula into the eggs of teleost fishes. The eggs of teleosts have several distinctive features of structure, cleavage and early development which make nuclear transplantation more difficult than with amphibia. Teleost eggs are telolecithal, with the yolk segregated from the active cytoplasm. We used eggs and embryos of Misgurnus fossilis L. (loach). In this fish, 30–60 min after natural or artificial activation of an egg, part of the cytoplasm migrates to the animal pole, forming a small polar cap where the nucleus is situated, completing meiotic division⁶. Thus, nuclei must be introduced into the animal pole region which occupies not more than one-tenth of the total egg.