Detection of aneuploidy in human and rodent sperm using FISH and applications of sperm assays of genetic damage in heritable risk evaluation.

Efficient molecular methods are being developed for detecting various types of cytogenetic genetic damage in sperm, especially numerical aneuploidy for chromosomes involved in trisomies that survive at birth. These methods provide new approaches for identifying potentially detrimental environmental exposures, genetic predisposition, chromosomal rearrangements, and physiologic factors which may increase a man's risk of fathering a genetically defective offspring. Corollary methods are also being developed for detecting sperm aneuploidy in laboratory rodents and these will be used to make inter-species comparisons of mutagen sensitivities and for investigating mechanisms of induction and persistence of aneuploidy. Validated assays for detecting genetic alterations in human and rodent sperm (of which sperm aneuploidy is a first example) permit comparisons of somatic and germinal response to mutagens within individuals, comparisons of human and rodent germinal sensitivity to mutagens, and can be applied in an extended parallelogram model to sperm for assessing heritable risk resulting from paternal mutagen exposures.