Circles around the farm animal embryo a Danish perspective
Callesen, H
With focus on the farm animal embryo, a short overview is given about my research activities over the last 35 years. These activities have been described in five circles, covering different key aspects of my work. The first circle included studies on the basic biology related to oocyte maturation and follicular endocrinology in superovulated dairy cows. Methods were developed to characterize the donor cows with respect to their production of transferable embryos, and some were implemented into a Danish MOET breeding plan. The second circle dealt with in-vitro embryo production in cattle with development of a protocol to produce such embryos at high and consistent levels. Several comparisons were made to reveal consequences of the artificial in-vitro methods on oocytes and embryos, but also through studies of the newborn calves. The third circle was related to development and implementation of a number of technologies within this broad field; examples are mentioned for both oocyte recovery from donor cows, different steps in the in-vitro embryo production system, new ways to perform vitrification and nuclear transfer, and finally a new system to determine oxygen consumption in single embryos. In the fourth circle is described activities from the last years, where work was done with focus on the pregnancy rates after insemination of the dairy cow in their post-partum period, and where somatic cell nuclear transfer was developed both as a technology in itself as well as a helping technique to produce transgenic pigs as models for important human diseases. The fifth and final circle is addressing and thanking the many colleagues and collaboration partners that I have been involved with during all the years to do this work. Nothing could or would have been the same without them and their participation.(AU)
Texto completo