New challenges in animal reproduction by advanced biotechnologies

During the past 50 years, numerous problems including gamete preservation, reproductive endocrinology, embryo technology and related areas, have been treated: some have been achieved and the others remains unsolved, whereas new issues are in progress. Now, new biotechnology in reproduction based on molecular genetics and embryology has rapidly developed. Recently, we developed a rapid FISH technique using a nonradioactive bovine Y chromosome-specific probe to determine the sex of bovine embryos within an hour, and to detect bovine Y chromosome-bearing spermatozoa after treatment of sperm head decondensation. Also, we developed a production system of porcine nuclear transfer embryos reconstituted with cultured cells, which are derived from blastocysts.