Conditional knockdown protocol for studying cellular communication using Drosophila melanogaster wing imaginal disc.

Apicobasal polarity determinants are potential tumor suppressors that have been extensively studied. However, the precise mechanisms by which their misregulation disrupts tissue homeostasis are not fully understood. Here, we present a comprehensive protocol for establishing a conditional RNAi knockdown of scribble in Drosophila wing imaginal disc. We describe steps for generating fly lines, conditional knockdown in host stocks, and sample preparation. We then detail procedures for imaging, image analysis, and verification of wing disc phenotypes by various antibodies. For complete details on the use and execution of this protocol, please refer to Huang et al.1.

Coordination of tissue homeostasis and growth by the Scribble-α-Catenin-Septate junction complex.

Maintaining apicobasal polarity (ABP) is crucial for epithelial integrity and homeostasis during tissue development. Although intracellular mechanisms underlying ABP establishment have been well studied, it remains to be addressed how the ABP coordinates tissue growth and homeostasis. By studying Scribble, a key ABP determinant, we address molecular mechanisms underlying ABP-mediated growth control in the Drosophila wing imaginal disc. Our data reveal that genetic and physical interactions between Scribble, Septate junction complex and α-Catenin appear to be key for sustaining ABP-mediated growth control. Cells with conditional scribble knockdown instigate the loss of α-Catenin, ultimately leading to the formation of neoplasia accompanying with activation of Yorkie. In contrast, cells expressing wild type scribble progressively restore ABP in scribble hypomorphic mutant cells in a non-autonomous manner. Our findings provide unique insights into cellular communication among optimal and sub-optimal cells to regulate epithelial homeostasis and growth.

Social Work in Funeral Homes, a Unique Chinese Practice?

Social workers were introduced to funeral homes in China amid the transition and expansion of both the funeral home industry and the social work profession and are proving to play a valuable, though under-researched role in serving not just clients but also communities and funeral home staff. Funeral home social work fills gaps in after-death care and mental health and is distinct from palliative, hospice, end-of-life, and bereavement social work. Based on the experiences of funeral homes that employ social workers, this article argues that this innovation may bring new ideas to bridge some of the service gaps in after-death care in China and globally. This article outlines the support that will be needed from funeral homes, social work service agencies, and educational and research institutes to facilitate further development of funeral home mental health and social services and to promote the professionalization of funeral home social workers in China.

Scribbled Optimizes BMP Signaling through Its Receptor Internalization to the Rab5 Endosome and Promote Robust Epithelial Morphogenesis.

Epithelial cells are characterized by apical-basal polarity. Intrinsic factors underlying apical-basal polarity are crucial for tissue homeostasis and have often been identified to be tumor suppressors. Patterning and differentiation of epithelia are key processes of epithelial morphogenesis and are frequently regulated by highly conserved extrinsic factors. However, due to the complexity of morphogenesis, the mechanisms of precise interpretation of signal transduction as well as spatiotemporal control of extrinsic cues during dynamic morphogenesis remain poorly understood. Wing posterior crossvein (PCV) formation in Drosophila serves as a unique model to address how epithelial morphogenesis is regulated by secreted growth factors. Decapentaplegic (Dpp), a conserved bone morphogenetic protein (BMP)-type ligand, is directionally trafficked from longitudinal veins (LVs) into the PCV region for patterning and differentiation. Our data reveal that the basolateral determinant Scribbled (Scrib) is required for PCV formation through optimizing BMP signaling. Scrib regulates BMP-type I receptor Thickveins (Tkv) localization at the basolateral region of PCV cells and subsequently facilitates Tkv internalization to Rab5 endosomes, where Tkv is active. BMP signaling also up-regulates scrib transcription in the pupal wing to form a positive feedback loop. Our data reveal a unique mechanism in which intrinsic polarity genes and extrinsic cues are coupled to promote robust morphogenesis.