bioRxiv Science⌕ Search

Biology subjects

Rojas-Rios, P.

Publications and source records attributed to Rojas-Rios, P..

3 recordsLinked to original sources

A high-throughput assay quantifies thermal scaling of Drosophila development with minute-scale precision

Precise regulation of developmental timing is essential for coordinated growth and robust development, yet staging remains technically challenging in many model systems. In Drosophila melanogaster, developmental timing has traditionally been assessed using low-throughput or coarse staging methods, limiting insight into how individual larval stages respond to environmental and genetic perturbations. Here, we present a high-throughput, real-time luminometry assay that enables continuous, automated measurement of postembryonic development in individual Drosophila larvae. By monitoring feeding-dependent luciferase activity, this method reliably detects transitions between larval instars and molts of individual larvae with minute-scale temporal resolution. Using this platform, we provide a quantitative, minute-precision, stage-resolved description of larval development across large cohorts, revealing distinct patterns of variability and weak temporal coupling between stages. We next examine how temperature shapes developmental timing across a broad thermal range. Increasing temperature uniformly accelerates larval development while preserving the proportional contribution of each stage, indicating that the temporal architecture of development is maintained as overall pace changes. Developmental rate follows predictable thermodynamic scaling within a defined temperature window, enabling precise estimation of thermal parameters at both whole-organism and stage-specific levels. Finally, we demonstrate that the assay is compatible with genetic perturbations. This work establishes a scalable, high-precision framework for measuring postembryonic development in Drosophila melanogaster. By revealing the modular and coordinated nature of larval growth, it enables systematic dissection of genetic, metabolic, and environmental control of developmental timing and provides a platform to explore fundamental principles of development and robustness across species.

developmental biology↗

piRNAs are regulators of metabolic reprogramming in stem cells

Stem cells preferentially use glycolysis instead of oxidative phosphorylation and this metabolic rewiring plays an instructive role in their fate; however, the underlying molecular mechanisms remain largely unexplored. PIWI-interacting RNAs (piRNAs) and PIWI proteins have essential functions in a range of adult stem cells across species. Here, we show that piRNAs and the PIWI protein Aubergine (Aub) are instrumental in activating glycolysis in Drosophila germline stem cells (GSCs). High glycolysis is required for GSC self-renewal and aub loss-of-function induces a metabolic switch in GSCs leading to their differentiation. Aub directly binds glycolytic mRNAs and Enolase mRNA regulation by Aub depends on its 5UTR. Furthermore, deletion of a piRNA target site in Enolase 5UTR leads to GSC loss. These data reveal an Aub/piRNA function in translational activation of glycolytic mRNAs in GSCs, and pinpoint a new mode of regulation of metabolic reprogramming in stem cells based on small RNAs.

developmental biology↗

Aubergine And piRNAs Repress The Proto-Oncogene Cbl For Germline Stem Cell Self-Renewal

PIWI proteins have essential roles in germ cells and stem cell lineages. In Drosophila, Piwi is required in somatic niche cells and germline stem cells (GSCs) for GSC self-renewal and differentiation. Whether and how other PIWI proteins are involved in GSC biology remains unknown. Here, we show that Aubergine (Aub), another PIWI protein, is intrinsically required in GSCs for their self-renewal and differentiation. Aub loading with piRNAs is essential for these functions. The major role of Aub is in self-renewal and depends on mRNA regulation. We identify the Cbl proto-oncogene, a regulator of mammalian hematopoietic stem cells, as a novel GSC differentiation factor. Aub represses Cbl mRNA translation for GSC self-renewal, and does so through recruitment of the CCR4-NOT complex. This study reveals the role of piRNAs and PIWI proteins in translational repression for stem cell homeostasis and highlights piRNAs as major post-transcriptional regulators in key developmental decisions.

developmental biology↗