Adultstem cellscoordinate intrinsic and extrinsic, local and systemic, cues to maintain the proper balance between self-renewal and differentiation. However, the precise mechanisms stem cells use to integrate these signals remain elusive. Here, we show that Escargot (Esg), a member of the Snail family of transcription factors, regulates the maintenance of somatic cyst stem cells (CySCs) in theDrosophilatestisby attenuating the activity of the pro-differentiationinsulin receptor(InR) pathway. Esg positively regulates the expression of an antagonist ofinsulin signaling,ImpL2, while also attenuating the expression ofInR. Furthermore, Esg-mediated repression of the InR pathway is required to suppress CySC loss in response to starvation. Given the conservation of Snail-family transcription factors, characterizing the mechanisms by which Esg regulates cell-fate decisions duringhomeostasisand a decline in nutrient availability is likely to provide insight into themetabolic regulationof stem cell behavior in other tissues and organisms.

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Escargot controls somatic stem cell maintenance through the attenuation of the insulin receptor pathway in Drosophila - Newswise