DL-Methionine (Sulphur-35) for labelling Unfertilized Mouse Eggs in Transplantation

Abstract

IN transplanting mammalian eggs to a fertile female, one can distinguish the fœtuses developed from transplanted eggs among recipient ‘native’ fœtuses by a genetic marker. The transplanted fœtuses from a brown mouse, C57BR, have pig-mented eyes, and the fœtuses developed from the native eggs of a Bagg albino (BALB/c) recipient are not pigmented. Such a technique has been used for testing the survival of eggs after various treatments¹. However, colour of eyes of mouse fœtuses cannot be observed until near the end of gestation. Labelling transplanted eggs with a radioactive isotope would serve as a means of distinguishing these eggs from native ones. The investigator could then determine the effect of any treatment of these eggs in vitro upon their fertilizability and early embryonic development after transplantation. Recent results obtained support the application of such a method.