The long term goal of our laboratory is to characterize and refine existing somatic cell transplantation procedures to reliably and economically produce genetically identical bovine offspring from donor cells of fetal and adult origin. Innovations in cloning via nuclear transfer would provide additional services to clients for the propagation of genetically superior cattle. The aim of this proposal is to investigate genotypic variation in the use of fetal fibroblast cell lines as donor nuclei for bovine nuclear transfer. Embryonic development and pregnancy rates will be determined and data will be correlated to the efficiency of creating embryonic stem cells from nuclear transfer embryos of each fibroblast line. It is our hypothesis that embryonic stem cells from nuclear transfer embryos may predict the in vivo totipotency of a cell line. These experiments will attempt to identify cell lines by in vitro methods that fail to produce pregnancies, preventing the costly and time-consuming transfer of embryos to recipients. Additionally, cell lines that produce pregnancies will allow for the rapid commercialization of those genotypes. Fibroblast lines that fail to produce pregnancies following nuclear transfer will be used for future experimentation on methods to enhance the cloning efficiency of all cell lines.
Anticipated Results/Potential Commercial Applications of Research::Developing the ability to identify clonable fibroblast cell lines by in vitro techniques will allow for a more rapid commercialization of the cloning technology. Purebred cattle producers will be the first to see the effects of an economical application of cloning. Cloned cattle will improve the genetic superiority within each herd, as well as produce greater numbers of valuable animals for sale and export. Still, research efforts are necessary to develop methods for reliable production of all genotypes. Additionally, as cloning efficiency improves and costs decrease, commercial cattlemen can utilize genetically identical hard sires to increase the uniformity of the calf crop.
