Fallopian tube and early cleavage in the mouse.

Abstract

TECHNIQUES have been perfected for the culture in vitro of late two cell mouse ova into blastocysts in simple chemically defined conditions1,2. Attempts to obtain development from earlier stages have failed, unless the ova were cultured in organ cultures of the fallopian tube3,4. These results suggested that the fallopian tube provides some critical contribution necessary for the development of the mouse zygote into the late two cell stage. Nevertheless, it has been a common experience that when the mouse zygote is cultivated independently of the fallopian tube a few cleave to the two cell stage and then cease development5. It has now been shown6, however, that a high percentage of zygotes cleave to two cell stages and then cease development when cultured in Waymouth7 medium supplemented with ATP, deoxynucleosides and a feeder layer of irradiated HeLa cells. These experiments suggest that the initial development of the mouse zygote is dependent on a supply of exogenous factors, additional to those required by later stages.