Capability of Mouse Embryos to form Chimeras and Developmental Potential of Chimeric Embryos in Culture and Uterine Environment

Authors: Sezen ARAT

Abstract: The aim this study was to determine the capability of embryos from two different strains to form chimeras and the developmental potential of these chimeric embryos in culture and uterine environment. A total of 148 eight-and sixteen-cell embryos were recovered from six C57BL/6 and six BALB/C strain donors. The zonae of the embryos were removed in acidified Tyrode's solution. Pairs of morulae, one from the C57BL/6 strain and the other from the BALB/C strain, were placed together in contact into the M16 droplets and cultured for 24 hours. When 70 pairs of embryos were cultured, 51 of them (73%) were aggregated and developed to chimeric morulae and blastocysts. Fourty-two of them (82%) were at the blastocyst stage. Twent-nine out of 42 chimeric blastocysts developed to term (69%) when transferred into the uteri of six 2.5-day pseudopregnants. Ten of the offspring (34.4%) were chimeric.

Keywords: Mouse, embryo transfer, embryo culture, chimera