A new source of polymorphic DNA markers for sperm typing: analysis of microsatellite repeats in single cells.

We show that dinucleotide and tetranucleotide repeat polymorphisms can be analyzed in single cells without using radioactivity or denaturing gels. This provides a rich new source of DNA polymorphisms for genetic mapping by sperm typing. The recombination fraction between two CA repeat polymorphisms was determined after whole genome amplification of single sperm, followed by typing of two different aliquots, one aliquot for each polymorphic locus. Single-cell analysis of microsatellites may also be valuable both for preimplantation genetic disease diagnosis based on single-blastomere or polar-body analysis and for the typing of forensic or ancient DNA samples containing very small amounts of nucleic acid.