Transvection regulates the sex-biased expression of a fly X-linked gene

Enhancer-gene interactions drive split In many species across the animal kingdom, male and female phenotypes differ. One such example is the wing spot seen in maleDrosophila biarmipes flies but not the female flies. Galouzis and Prud'homme investigate the X-linkedyellow gene and its enhancer. Investigating the genetics of the trait, they found evidence that the male-specific phenotype is caused by a trans interaction between the enhancer and gene that silences the gene when it is present in only one copy in the male (which only has a single X chromosome) versus the two copies found in the female. This gene thus appears to be regulated by differing genomic interactions in male and female flies and is an example of the phenomenon known as transvection.Science , this issue p.396