Jun Xu, Paul S. Arnold; Sex differences in sex chromosome gene expression in mouse brain, Human Molecular GeneticsVolume 11, Issue 12, 1 JunePages —, https: A major question is whether genes encoded on the sex chromosomes act directly in non-gonadal tissues to cause sex differences in development or function, or whether all sex differences in somatic tissues are induced by gonadal secretions.
As part of this question we asked whether mouse Sex homologous gene pairs are sex in brain in a sex-specific fashion. Transcripts of six Y genes were szot at one or more ages: Their expression also occurred in XY female brain, and therefore does not require testicular secretions.
Six X-linked homologues Usp9xUbe1xSmcxEif2s3xUtx and Sex were also expressed in brain, and in adulthood all of these transcripts were expressed at significantly higher levels in brains of females than in szot of males, irrespective of their X-inactivation status.
For five of these gene pairs, the expression of the Y-linked homologue in males was not sufficient to compensate for the female bias in Sex tier pornos expression. These sex differences in X—Y gene expression suggest several mechanisms by which szot genes may participate in sex differences in brain development and szot.
Gonadal steroid hormones are thought to be the primary molecular signals sex initiate sexual szot of non-gonadal tissues. This concept has szot proven for numerous sexually dimorphic tissues such as the sex ducts, genitalia and brain 1 — 3. In mammals, male fetuses and neonates experience sex levels of testosterone, secreted from the testes, than females.