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

Abstract

Primed in situ labeling (PRINS) can be used to localize DNA segments too small to be detected by fluorescence in situ hybridization. By PRINS we identified 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 generally 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 dysgenesis. SRY signals were identified on Xp22 in one XX male but not in the other. They were identified in the corresponding region (Xp22) of the der(X) in the azoospermic male with Xp-Yp interchange. SRY signals were not observed in normal XX females. Presence of SRY in DNA samples from the various subjects was confirmed by polymerase chain reaction. We conclude that PRINS is ideal for rapid localization of single copy genes and small DNA segments in general.

Disorders of Sexual Differentiation in the Adolescent

“…46,XX sex reversal (XX maleness) present with a spectrum of findings including normal male differentiation and may escape diagnosis until puberty. Most patients in this group have a functional SRY gene, 6 commonly located on one of the X chromosomes; those who are SRY‐negative often manifest ambiguous genitalia 7 . In addition to SRY translocation, 46,XX sex reversal may result from SF1 and DAX1 mutations.…”

Recent findings on the genetics of disorders of sex development

“…Denys-Drash syndrome is caused by missense mutations affecting the zinc-finger DNA binding region of the WT1 gene, and is characterized by varying degrees of gonadal dysgenesis (partial to complete), renal failure early in childhood due to diffuse mesangial sclerosis, and increased risk for Wilms tumor and gonadoblastoma [16]. Isolated diffuse mesangial sclerosis has been attributed to WT1 mutations, in some cases the same missense mutations that have been described in association with Denys-Drash in other individuals [15,17–20]. …”

De la conception du PRINS à son couronnement

“…Dans le domaine de la biologie humaine, elle a principalement servi au diagnostic cytopathologique [12] et cytogénétique [13]. De récents développements techniques ont permis la détection in situ de séquences uniques [14][15][16][17][18][19][20], ouvrant ainsi de nouvelles perspectives pour cette technique. Initialement, la technique PRINS était utilisée pour détecter un seul chromosome qui était révélé à l'aide d'un seul fluorochrome.…”

“…Ces échecs semblent essentiellement dus à la faible extension de l'élongation, qui ne dépasse pas une centaine de paires de bases [36]. Une étape importante a été franchie avec la publication de l'identification in situ des gènes SRY et SOX3 [14,15]. Les protocoles développés par Kadandale et al [15,16] renouent avec la simplicité initiale de la technique PRINS où chaque étape a été optimisée pour amplifier fortement REVUES DOSSIER TECHNIQUE le signal sans produire de bruit de fond.…”