Localization of SRY by primed in situ labeling in XX and XY sex reversal

Primed in situ labeling (PRINS) can be used to localize DNA segments too sm all to be detected by fluorescence in situ hybridization. By PRINS we ident ified the SRY gene in two XX males, a woman with XY gonadal dysgenesis, and an azoospermic male with Xp-Yp interchange. Because PRINS has been used ge nerally in the study of repetitive sequences, we modified the technique for study of the single copy 2.1-kb SRY sequence, SRY signals were identified at band Yp11.31p11.32 in normal XY males and in the woman with XY gonadal d ysgenesis. SRY signals were identified on Xp22 in one XX male but not in th e other. They were identified in the corresponding region (Xp22) of the der (X) in the azoospermic male with XpYp interchange, SRY signals were not obs erved in normal XX females. Presence of SRY in DNA samples from the various subjects was confirmed by polymerase chain reaction, We conclude that PRIN S is ideal for rapid localization of single copy genes and small DNA segmen ts in general. (C) 2000 Wiley-Liss, Inc.