Chromatin structure and gene expression in germ line and somatic cells.

Abstract

The paternal genome is, according to recent reports, somehow marked for selective expression during early development. For example, the male pronucleus is essential for the formation of the extraembryonic layers during embryogenesis of the mouse (Surani et al., 1984; McGrath and Solter, 1984). In addition, the paternal X chromosome is selectively inactivted in the extraembryonic tissues of various species (West et al., 1977; Takagi et al., 1978; Harper et al., 1982). Thus, while it is formally possible that paternal DNA is completely reprogrammed on fertilization by components of the egg, there is evidence for the templating of information for differential gene expression by some component of sperm. We have initiated a series of experiments to determine whether the structure of sperm chromatin or the pattern of methylation of sperm DNA (or both) might provide a basis for the templating of information important in the selective expression of patenal genes early in development. The rationale for these experiments is based on observations concerning the relationship between chromatin structure and gene expression in somatic cells.