The expression of the Gadd45g gene is essential in the determination of sex, fertility and development of testicles , as shown by an investigation led by the Higher Council for Scientific Research (CSIC). The work, published in the journal PLOS ONE , reveals that blocking this gene prevents the development of testes and causes the growth of female sexual organs, regardless of the presence of the Y chromosome.
The Gadd45 gene family is made up of a, b, and g. Different experiments have silenced each of them and their different combinations in pairs. Jesús Salvador, CSIC researcher at the National Center for Biotechnology and co-author of the research, concludes from the results “that Gadd45g is the only member of the family that plays a key role in determining sex and developing testicles” . For the Spanish scientist, it was “surprising to discover that in his absence all mouse offspring were phenotypically female, even though they were genetically male, having the Y chromosome .”
Gadd45g is a positive regulator of the SRY gene, which is located on the Y chromosome. According to the work, the absence of Gadd45g prevents the expression of SRY, which slows the development of male gonads.
Less than one in 4,500 newborns in the world has abnormalities of sexual differentiation . Their low frequency classifies them as rare pathologies. They are caused by different alterations during some stage of fetal development. Salvador explains that, although some mutations associated with these pathologies have been described, most of them do not have a defined diagnosis.
