HLA genotyping by using spermatozoa: evidence for haploid gene expression.

Serologically defined HLA-A and HLA-B antigens are expressed in a haploid manner on the surface of spermatozoa. This enabled the HLA-genotypes of four men to be determined by using sperm. This technique will mean that the HLA genotype of potential male graft recipients and others can be determined more easily and even when families are not available. These findings also provide strong evidence that some cell products are encoded by a haploid genome.