The practical application of the regulation of a distinguishable porcine blastomere, causing it to differentiate into the inner cell mass, hence the offspring, will be investigated.Porcine blastomeres will be obtained by microdissection of an 8-cell embryo recovered from a pure red breed and then intermingled with blastomeres of a 4-cell embryo recovered from a pure white breed. The development of the resulting chimaeric embryos will be monitored at term (1) after in utero transplantation, and (2) after in utero transplantation following a temporary culture period in the oviduct of a porcine recipient. Fifty percent of the embryos cultured in oviducts will be protected with a 1.0 percent agar coating.Red piglets born are assumed to be twins originating from the 8-cell embryos. Piglets born white or sandy colored will be recorded as either a pure white or a chimaeric piglet. One-eighth porcine blastomeres are expected to develop similar to one-eighth blastomeres of other species.Solving the technical problems of development in vivo of one-eighth porcine blastomeres and their regulation, resulting in distinguishable offspring, will increase the practical use of embryo transfer in the commercial swine industry.National Institute of Child Health and Human Development (NICHD)
