DIA3 phenotyping in human semen and seminal stains by isoelectric focusing

The polymorphism of DIA3 was investigated by isoelectric focusing in semen samples from 235 unrelated Japanese volunteers and patients. Besides the three common phenotypes seven samples of the type 3-1 were observed. However, readable isoenzyme patterns were not demonstrated in semen samples of oligospermia under about 10 X 10(6)/ml sperm cells. The allele frequencies were DIA3*1 = 0.821, DIA3*2 = 0.164, and DIA3*3 = 0.015. The DIA3*1 frequency in oligospermia (0.765) was lower than that in normospermia (0.836). The isoelectric focusing method was successfully applied to phenotyping DIA3 in seminal stains; each phenotype was demonstrated at 37 degrees C for up to 4 weeks, at room temperature for up to 8 weeks, and at 4 degrees C for over 12 weeks after stain formation. In vaginal swabs the isoenzyme bands were very faint and not identifiable.