ORIGIN AND ROLES OF GENOMIC METHYLATION PATTERNS IN MALE GERM-CELLS

The epigenetic modification of DNA by methylation at cytosine residues is initiated in the germ line and is required for normal embryonic de velopment in mammals. Marked differences in genomic methylation betwee n male and female gametes arise during gametogenesis and have been imp licated in genomic imprinting. While DNA methylation patterns for diff erent types of gene sequences are known to change during spermatogenes is, the precise role(s) of DNA methylation in the normal development o f male germ cells is poorly understood. The expression of the one know n active form of DNA methyltransferase is highly regulated during sper matogenesis and may provide insight into mechanisms underlying the est ablishment of methylation patterns in germ cells.