Study reveals key role of mRNA's 'fifth nucleotide' in determining sex in fruit flies

A team of scientists has shown how a common mRNA modification, N6-methyladenosine (m6A), regulates gene expression to determine the sex of fruit flies. The function of m6A, an mRNA modification known as the 'fifth nucleotide', has long been a mystery. But a new study has revealed that m6A plays a key role in the regulation of the Sex-lethal (Sxl) gene, which controls sex determination of the fruit fly Drosophila.