We know much about the differences between men and women – the X is the default pathway and the Y under the microscope looks as worn down and “misshapen as a stubbed-out cheroot“. There turns out to be something really new. So far all effects of Y genes on sex determination have been attributed to SRY, the testis determining gene (NR0B1, FOXL2 and WNT04 are probably ovary-determining).
The careful analysis of an Italian pedigree now described a new gene that can reversal XX to male when being disrupted: It is R-spondin 1 (or RSPO1), a growth factor that may act through ß-catenin stabilization and synergize with Wnt.
Do you know renember the nice cartoon of the Y chromosome with the HUH? selective hearing loss ;-) it is finally RSPO1. Yea, yea.