Exploring the role of Nerfin-1 and Cph transcription factors in Drosophila melanogaster intestinal stem cell regulation

The adult Drosophila melanogaster midgut serves as a powerful model for studying how intestinal stem cell (ISC) self-renewal and differentiation are balanced to maintain tissue homeostasis. Notch signaling pathway is known to act as the primary switch with regards to ISC fate determination since high Notch activity induces an enterocyte (EC) phenotype while low Notch activity induces an enteroendocrine (EE) phenotype. In this model, high Notch activity in enteroblasts (EB) (EC progenitor) induces Klumpfuss (Klu), which appears to maintain the absorptive lineage. Specifically, Klu represses the expression of the transcription factor Chronophage (Cph) via direct binding. Cph was found to play a key role in promoting ISC-proliferation and EE-differentiation (King et al.2024). Among the downstream effectors of Cph is the transcription factor Nervous fingers 1 (Nerfin-1). This study focused on Cph and Nerfin-1, in order to elucidate their specific roles in regulating ISC proliferation and differentiation. The results presented here confirm that Cph and Nerfin-1 are genetic gatekeepers that partake in the stabilisation of the Drosophila intestinal progenitor pool. While Klu acts as a gradual repressor of Cph to manage lineage differentiation, Nerfin-1 functions as a dose dependent regulator downstream of Cph to maintain stem cell (SC) identity and prevent the exhaustion of the stem cell pool. Ultimately, this network of TF’s ensures a balanced transition from a self-renewing progenitor state to terminal differentiation, particularly within the secretory (EE) lineage. Further replications of these experiments in combination with orthogonal validation as well as the implementation of next generation sequencing and functional studies will shed light in the tightly regulated process of asymmetric SC division taking place in the Drosophila melongaster midgut.