Histone demethylase Kdm5 and PIWI pathway proteins regulate sex-specific abdominal pigmentation in Drosophila

Researchers have posted a preprint to bioRxiv describing results from an RNAi screen conducted using the yellow-Gal4 driver system in Drosophila melanogaster, which expresses during the pupal stage when abdominal pigmentation genes are activated. The screen identified the histone demethylase Kdm5 — a KDM5 family chromatin regulator — and the ARGONAUTE/PIWI pathway proteins Piwi and Aubergine as components of the gene regulatory network controlling female-specific abdominal pigmentation.

In D. melanogaster, abdominal pigmentation is sexually dimorphic: males show fully pigmented posterior abdominal segments, while females display a characteristic posterior melanin stripe. The precise regulatory circuitry governing this dimorphism has been an active area of study in evo-devo (evolutionary developmental biology) research, as pigmentation provides a tractable model for understanding how gene regulatory networks generate morphological diversity.

The involvement of Piwi and Aubergine — proteins principally studied in the context of small RNA-mediated transposon silencing in the germline — in a somatic pigmentation context represents a potentially novel finding, though the preprint has not yet undergone peer review and further mechanistic dissection will be needed to establish causal links.

This work is relevant to researchers studying chromatin regulation, small RNA biology, and the genetic basis of sexually dimorphic traits. A cluster on Drosophila cuticle pigmentation and the Hippo pathway was published in Genetic Current on 22 August 2026; that prior cluster addressed a distinct signalling pathway and experimental system, so this preprint is treated as a separate story.