Del(Y)1H

This Y Chr deletion resulted from asymmetric recombination during male meiosis between the short arm of a Y Chr (Yp) of BALB/c origin and an X Chr carrying Tp(Y)1CtSxr-a. Whereas Sry (sex determining region of Chr Y) and 16 other single-copy genes and pseudogenes on Yp appear intact by Southern blot or PCR analysis, the unequal exchange resulted in deletion of 3-4 Mb, including 90% of the Rbmy (RNA binding motif protein, Y Chr) repeat sequence family, which resides between Sry and the centromere and normally comprises at least 50 copies. Sry transcripts are undetectable by semiquantitative RT-PCR analysis of RNA from the genital ridges of 11.5 day post coitus (dpc) XYDel(Y)1H and XXYDel(Y)1H embryos; in contrast, transcripts from Kdm5d, which maps distal to Sry between Zfy1 and Zfy2, are similarly abundant in XYDel(Y)2H and XY 11.5 dpc genital ridges. (J:15425, J:29526, J:46791)