Alza, L. | Search bioRxiv

bioRxiv2025

Pro-tumoral Ca2+ signaling is dependent on Ca-alpha1T and Slowpoke channels in Drosophila melanogaster glioma

BackgroundIon channel-mediated cytosolic Ca2+ oscillations play a crucial role in promoting the growth of glioblastoma, a tumor of poor prognosis. Here, we have studied the roles of Ca-1T and Slowpoke ion channels in a Drosophila melanogaster glioblastoma model. Although their mammalian orthologs have been implicated in glioblastoma cell viability in vitro, their oncogenic potential remains uncharacterized in a complex in vivo context. ResultsWe show that glial-specific RNAi targeting Ca-1T and Slowpoke in gliomas reduces glioma cell number and membrane extension and decreases glioma cell Ca{superscript 2} activity and downstream activation of PI3K and pRIII/pERK signaling. Moreover, Slowpoke knockdown significantly extends glioma fly survival to near-control values and improves glioma-associated neurodegeneration. RNAseq transcriptomic analysis reveals shared regulation by both channels of pathways involved in metabolic rewiring, cell adhesion and excitatory neurotransmission, while uncovering distinct effects on synaptic function. ConclusionsBoth Ca-1T and Slowpoke are essential for pro-tumorigenic Ca{superscript 2}-dependent signaling in Drosophila gliomas. Common effects observed upon gene knockdown support a coordinated function for these channels at the plasma membrane. Nevertheless, their distinct impacts on survival and gene expression profiles highlight non-redundant roles. Notably, Slowpoke knockdown promotes increased survival and neuroprotection, associated with the repression of synaptic genes aberrantly upregulated in gliomas, thereby identifying Slowpoke as a promising therapeutic target in glioblastoma.

cancer biology↗

bioRxiv2017

Down Feather Structure Varies Between High And Low Elevation Male Andean Torrent Ducks (Merganetta armata)

Feathers are one of the defining characteristics of birds and serve a critical role in thermal insulation and physical protection against the environment. Feather structure is known to vary among individuals, and it has been suggested that populations exposed to different environmental conditions may exhibit different patterns in feather structure. We examined both down and contour feathers from two populations of male Torrent Ducks (Merganetta armata) from Lima, Peru, including one high-altitude population from the Chancay-Huaral River at approximately 3500 meters (m) elevation and one low-altitude population from the Chillon River at approximately 1500 m. Down feather structure differed significantly between the two populations. Ducks from the high-altitude population had longer, denser down compared with low-altitude individuals. Contour feather structure varied greatly among individuals but showed no significant difference between populations. These results suggest that the innermost, insulative layer of plumage (the down), may have developed in response to lower ambient temperatures at high elevations. The lack of observable differences in the contour feathers may be due to the general constraints of the waterproofing capability of this outer plumage layer.\n\nResumenEl plumaje es una caracteristica que define a las aves y cumple roles criticos en el aislamiento termico y proteccion fisica del ambiente. Se sabe que la estructura de las plumas varia ente individuos, y se ha sugerido que poblaciones expuestas a diferentes condiciones ambientales pueden exhibir diferentes patrones en la estructura de las plumas. En este estudio se examinaron tanto el plumon como las plumas de contorno de machos adultos del Pato de los Torrentes (Merganetta armata) de dos poblaciones, una en el rio Chancay-Huaral a 3,500 msnm y otra en el rio Chillon a 1,500 msnm, ubicadas en Lima, Peru. La estructura de los plumones difiere significativamente entre las dos poblaciones. Los patos de la poblacion a grandes elevaciones tienen plumones largos, y densos comparados con los individuos de las partes bajas. La estructura de las plumas de contorno varia ampliamente entre individuos pero no muestra diferencias significativas entre poblaciones. Estos resultados sugieren que las diferencias entre las capas interiores de aislamiento del plumaje (plumon), haberse desarrollado como respuesta en ambientes de bajas temperaturas a grandes elevaciones. En cambio la falta de detectables diferencias en las plumas de contorno puede ser debido a la constante seleccion en la capacidad impermeable de la capa de plumas exteriores.

zoology↗