GENOMIC IMPRINTING IN TESTICULAR GERM-CELL TUMORS

Genomic imprinting refers to the parental origin-specific functional d ifference between the paternally and maternally-derived mammalian hapl oid genome. Normal embryogenesis depends on the presence of both a pat ernal and a maternal copy of particular chromosomal regions, containin g the so-called imprinted genes. Genomic imprinting is established som ewhere in the maturation from a primordial germ cell to a mature gamet e, either spermatid or oocyte. We discuss the value of testicular canc ers, especially those derived from the germ cell lineage, as a model t o study erasement of the biparental pattern of genomic imprinting as p resent in the zygote and establishment of the paternal pattern during spermatogenesis. In addition, we will present data on the presence of X-inactivation in these cancers.