Honorable prize 2022: Dr. Charalampos Babis Galouzis

→ Prize 300 €

The honorable prize for the 2022 SFBD Thesis Prize has been awarded Dr. Charalampos ‘Babis’ GALOUZIS (Marseille Developmental Biology Institute, Marseille, director Dr. Benjamin Prud’homme) for his thesis entitled “Trans-homolog interaction of yellow controls its sex-biased expression pattern in the wing of Drosophila biarmipes”. His work was published in Current Opinion in Cell Biology and Science.

The work of the winner:

During his thesis, Babis Galouzis studied the sex-specific regulation of the X-linked gene yellow, which in Drosophila biarmipes, a species closely related to the better-known Drosophila melanogaster, is required for the formation of a pigmented spot only present on the wing of males.
Babis discovered that, contrary to the common-held belief, the sex-specific pattern of expression of yellow in D. biarmipes wing is not controlled by genes of the sex determination pathway, but by interallelic interaction, a regulatory mechanism known as transvection. The two yellow alleles can physically and functionally interact in XX females, thus leading to the silencing of a particular enhancer responsible for the wing spot expression pattern, but not in XY males, thereby creating a male-biased expression pattern of yellow.
These results, described in a paper entitled ‘Transvection regulates the sex-biased expression of a fly X-linked gene’, published in Science, are exciting for two reasons. First, they reveal for the first time the role of transvection in the regulation of a Drosophila gene under physiological conditions.  Second, this is the first example of sex-specific gene regulation that is independent of the sex determination pathway. The jury chose to reward the exceptional quality of Babis’ work with an accessit prize.