Gaining Wings to FLY: Using Drosophila Oogenesis as an Entry Point for Citizen Scientists in Laboratory Research.

Citizen science is a productive approach to include non-scientists in research efforts that impact particular issues or communities. In most cases, scientists at advanced career stages design high-quality, exciting projects that enable citizen contribution, a crowdsourcing process that drives discovery forward and engages communities. The challenges of having citizens design their own research with no or limited training and providing access to laboratory tools, reagents, and supplies have limited citizen science efforts. This leaves the incredible life experiences and immersion of citizens in communities that experience health disparities out of the research equation, thus hampering efforts to address community health needs with a full picture of the challenges that must be addressed. Here, we present a robust and reproducible approach that engages participants from Grade 5 through adult in research focused on defining how diet impacts disease signaling. We leverage the powerful genetics, cell biology, and biochemistry of Drosophila oogenesis to define how nutrients impact phenotypes associated with genetic mutants that are implicated in cancer and diabetes. Participants lead the project design and execution, flipping the top-down hierarchy of the prevailing scientific culture to co-create research projects and infuse the research with cultural and community relevance.

Sequential events during the quiescence to proliferation transition establish patterns of follicle cell differentiation in the Drosophila ovary.

Stem cells cycle between periods of quiescence and proliferation to promote tissue health. In Drosophila ovaries, quiescence to proliferation transitions of follicle stem cells (FSCs) are exquisitely feeding-dependent. Here, we demonstrate feeding-dependent induction of follicle cell differentiation markers, eyes absent (Eya) and castor (Cas) in FSCs, a patterning process that does not depend on proliferation induction. Instead, FSCs extend micron-scale cytoplasmic projections that dictate Eya-Cas patterning. We identify still life and sickie as necessary and sufficient for FSC projection growth and Eya-Cas induction. Our results suggest that sequential, interdependent events establish long-term differentiation patterns in follicle cell precursors, independently of FSC proliferation induction.

Cholesterol and CDON Regulate Sonic Hedgehog Release from Pancreatic Cancer Cells.

Background: Sonic Hedgehog (Shh) is a tightly regulated membrane-associated morphogen and a known driver of tumorigenesis in pancreatic ductal adenocarcinoma (PDAC). After processing, Shh remains at the plasma membrane of Shh producing cells, thereby limiting its distribution and signal strength. In PDAC, the release of Shh from tumor cells is necessary to promote a tumor-permissive microenvironment. Mechanisms regulating Shh sequestration and/or release from tumor cells to signal distant stromal cells are not well known. Previously, our laboratory demonstrated that the Drosophila transmembrane protein Boi, sequesters Hh at the membrane of Hh-producing cells. In response to dietary cholesterol or in the absence of boi, Hh is constitutively released to promote proliferation in distant cells. In this study, we investigated the conservation of this mechanism in mammals by exploring the role of the human boi homolog, CDON, in PDAC. Methods: Using PDAC cell-lines BxPC-3, Capan-2, and MIA PaCa-2, along with normal pancreatic epithelial cells (PDEC), we investigated Shh expression via Immunoblot and real-time, quantitative polymerase chain reaction in addition to Shh release via enzyme-linked immunoassay following cholesterol treatment and/or transfection with either RNA interference to reduce CDON expression or with human CDON to increase expression. Results: Consistent with our Boi model, CDON suppresses Shh release, which is alleviated in response to dietary cholesterol. However, over-expressing CDON suppresses cholesterol-mediated Shh release in some PDAC contexts, which may be relative to the mutational burden of the cells. Conclusion: Identifying mechanisms that either sequester or stimulate Shh release from the tumor cell membrane may provide new avenues to reduce signaling between the tumor and its surrounding environment, which may restrain tumor development.