Disease relevance of STAG3

• STAG3, a novel gene encoding a protein involved in meiotic chromosome pairing and location of STAG3-related genes flanking the Williams-Beuren syndrome deletion [1].

High impact information on STAG3

• We have mapped the human STAG3 gene to the 7q22 region of chromosome 7; six human STAG3-related genes have also been mapped: two at 7q22 near the functional gene, one at 7q11.22, and three at 7q11.23, two of them flanking the breakpoints commonly associated with the Williams-Beuren syndrome (WBS) deletion [1].
• STAG3 is expressed specifically in testis, and immunolocalization experiments show that STAG3 is associated to the synaptonemal complex [1].
• Since the WBS deletion occurs as a consequence of unequal meiotic crossing over, we suggest that STAG3 duplications predispose to germline chromosomal rearrangement within this region [1].
• Immunofluorescence results suggest that a cohesin complex containing Rad21 and STAG2 cooperates with a STAG3-specific complex to maintain sister chromatid cohesion during the diplotene stage of meiosis [2].
• In normal and atretic human fetal oocytes, from leptotene to diplotene stages, REC8 and STAG3 colocalize in fibers [3].

Anatomical context of STAG3

• Three meiosis-specific cohesin subunits have been reported in mammals, REC8, STAG3 and SMC1 beta; their expression in mouse spermatocytes has also been described [3].

References