Ecdysone signaling-induced dumpless1 expression controls nurse cell dumping in Drosophila oogenesis

Area of Science:

• Developmental Biology
• Cell Biology
• Genetics

Background:

• Nurse cell (NC) dumping is vital for oocyte development, involving cytoplasmic transfer from NCs to the oocyte.
• The precise regulatory mechanisms governing NC dumping remain largely unknown.

Purpose of the Study:

• To elucidate the regulatory mechanism of NC dumping in Drosophila oogenesis.
• To identify key molecular players and signaling pathways involved in this process.

Main Methods:

• Utilized CRISPR/Cas9 gene editing to knock out the dumpless1 gene and its functional domain.
• Investigated gene expression changes, protein localization, and cellular organization using molecular and imaging techniques.
• Performed rescue experiments by overexpressing or knocking down specific genes in relevant cell types.

Main Results:

• Ecdysone signaling in stretch follicle cells (SFCs) induces dumpless1 expression, a zinc finger transcription factor.
• Loss of dumpless1 function or its ZAD domain impairs NC dumping.
• Dumpless1 depletion affects integrin βPS expression, Rho1 signaling (p-MLC), and actin organization in NCs.
• Integrin βPS and Rho1 signaling pathway components mediate the effects of dumpless1 on NC dumping.

Conclusions:

• Dumpless1 acts as a crucial effector of ecdysone signaling in SFCs, regulating NC dumping.
• Identified a novel multicellular regulatory mechanism involving somatic-germline communication via the integrin βPS-Rho1-p-MLC axis.
• This study reveals a key pathway controlling cytoplasmic transfer during Drosophila oogenesis.