Chromatin remodeling and nuclear reprogramming in domestic animal clones and embryonic stem cells

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The production of viable embryos, embryonic stem cell lines, and live animals using cloning technologies has confirmed that sufficient reversal of differentiated fetal and adult genomes can be achieved.  However, high embryonic, fetal and neonatal deaths with abnormalities affecting the placenta, the respiratory and circulatory systems and growth of the fetus and neonate clone greatly lower the live birth rate to ~1-5% indicating that this reprogramming process is inadequate most of the time.     This proposal outlines a continuing research program based on the hypothesis that the artificial and sub-optimal culture environments alter the chromatin structure and function of cells and embryos - modifications that are amplified and further altered during the in vitro manipulations and development of embryos, embryonic stem cells and live born animals derived from the cloning procedures.  The specific aims of this research program are to: 1) Enhance nuclear reprogramming of the donor genome; 2) Evaluate the efficiency of epigenetic and nuclear reprogramming; 3) Compare and contrast global gene expression patterns between embryo clones and fetuses with their in vitro fertilized (IVF) and in vivo produced counterparts.     Our unique combination of micromanipulation skills, various quantitative gene expression and chromatin structure analysis tools, and techniques for animal cloning and embryonic stem cell derivation and differentiation in multiple domestic species allow us to evaluate the efficacy and safety of somatic cell nuclear transfer technologies and permits improvements to help transfer this technology to applied endeavours.  This research program will improve our fundamental understanding of nuclear reprogramming events and may allow for strategies that will improve the live birth rates of domestic animal clones and to genetically evaluate embryonic stem stems for their potential uses in transplantation-based therapies.