John R. McCarrey, Ph.D.
University of Texas at San Antonio

(210) 458-4507
john.mccarrey@utsa.edu

Our research invloves basic research centered on the mechanisms regulating the development, differentiation and manipulation of germ cells and stem cells in mammals. We are interested in genetic and epigenetic mechanisms that regulate gene activity, including protein-DNA interactions, chromatin structure, histone modifications, and DNA methylation as regulators of gene expression. We are also involved in studies of genomic imprinting by which one copy of a gene (either from the father or the mother) is preferentially expressed while an identical copy from the other parent is repressed in the same cell. In addition, we are examining the processes of X-chromosome activity and inactivity during gametogenesis and early embryogenesis in mammals, including an analysis of the evolution of these mechanisms in eutherian and marsupial mammals.

Recently initiated projects include a study of germline-specific reprogramming in cloned mice. For this project we are examining germ cells from cloned mice to determine if they undergo the same genetic and epigenetic programming as do germ cells in normally conceived mice. We are also examining genetic integrity in mice produced by assisted reproductive technology (ART) and by cloning. We next plan to investigate the extent to which genetic integrity is maintained in stem cells derived from mouse embryos produced by therapeutic cloning. Another recent project is the development of ART, stem cell research, transgenic technology, and therapeutic cloning in baboons. Baboons represent an important nonhuman primate experimental animal model for studies of genetic diseases or inherited risk factors that contribute to complex diseases. We seek to develop ART, stem cell and transgenic methodologies in this species to facilitate further studies of genetic factors that contribute to disease in primates, and to investigate therapeutic methods to treat these diseases.

We are also involved in collaborative studies of expressed sequence tags (EST's) for different spermatogenic cell types in the mouse, and the use of microarrays and DNA chips to profile gene expression patterns during germ cell development in both sexes, and during spermatogenesis in the mouse in young and aging adults. We are also using microarrays to examine gene expression patterns in the baboon brain.

PUBLICATIONS:
Namekawa SH, Park PJ, Zhang LF, Shima JE, McCarrey JR, Griswold MD, Lee JT. Postmeiotic sex chromatin in the male germline of mice. Curr Biol. 2006 Apr 4;16(7):660-7.

Wang PJ, Page DC, McCarrey JR. Differential expression of sex-linked and autosomal germ-cell-specific genes during spermatogenesis in the mouse. Hum Mol Genet. 2005 Oct 1;14(19):2911-8. Epub 2005 Aug 23.

McCarrey JR, Geyer CB, Yoshioka H. Epigenetic regulation of testis-specific gene expression. Ann N Y Acad Sci. 2005 Dec;1061:226-42.

Yamazaki Y, Low EW, Marikawa Y, Iwahashi K, Bartolomei MS, McCarrey JR, Yanagimachi R. Adult mice cloned from migrating primordial germ cells. Proc Natl Acad Sci U S A. 2005 Aug 9;102(32):11361-6. Epub 2005 Jul 29.