Biology subjects

Zaada, D. S. Y.

Publications and source records attributed to Zaada, D. S. Y..

3 recordsLinked to original sources

bioRxiv2026

Cholesterol links blood feeding to mosquito development and reproduction

Mosquitoes undergo major metabolic remodeling as they transition from aquatic larvae to terrestrial, blood-feeding adults, yet the biochemical principles supporting these life cycle transitions remain poorly understood1. Early metabolic studies established that mosquitoes are sterol auxotrophs2,3; however, the extent to which this auxotrophy influences developmental progression and stage transitions remains unknown. Here, using sterol-defined culture systems, we uncover a central and stage-specific role for sterol metabolism in mosquitoes. We show that eggs of multiple mosquito species, from Anopheles gambiae (Giles 1902; hereafter A. gambiae) to Aedes species in both wild and laboratory settings, are enriched in cholesterol consistent with maternal provisioning. In the Asian tiger mosquito Aedes albopictus (Skuse, 1894; hereafter Ae. albopictus), egg cholesterol supports early larval development, after which larvae depend on the acquisition of dietary sterols to complete development. Like cholesterol, dietary plant- and fungal-derived sterols support late larval development; however, their utilization is associated with the accumulation of the intermediate sterol desmosterol. Using biochemical assays, we showed that desmosterol is converted to cholesterol through the activity of the Ae. albopictus DHCR-24 enzyme. This metabolic axis of desmosterol-to-cholesterol conversion supports late larval development when mosquitoes rely on plant- and fungal-derived sterols for development. dhcr-24 expression is upregulated during the developmental window of dietary sterol acquisition and is selectively induced by its substrate desmosterol, revealing a diet-encoded regulatory mechanism that coordinates metabolic conversion capacity. Extending the analysis to adulthood, we developed a sterol-defined artificial blood-feeding system that enables precise manipulation of dietary sterols in reproductive females and show that cholesterol availability in the diet of females is an essential metabolic driver of egg laying. These findings reveal a developmentally coordinated sterol-use strategy in the life cycle of Aedes mosquitoes, identifying sterol utilization as a central physiological axis linking development, blood feeding, and reproduction, and revealing a sterol-dependent metabolic vulnerability in mosquitoes. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=178 SRC="FIGDIR/small/725405v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@13c7843org.highwire.dtl.DTLVardef@fb9203org.highwire.dtl.DTLVardef@2f0db8org.highwire.dtl.DTLVardef@12db355_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2025

3D-Feedy: An open and portable membrane feeder for mosquito research

Female mosquitoes must feed on blood to produce eggs, a natural behavior that also drives disease transmission. Vector biology research and the development of novel control tools depend on reliable methods for blood feeding of laboratory-reared mosquitoes. Artificial membrane feeders have provided a practical alternative to live animals for decades. However, commercial systems are typically expensive, difficult to repair and are tethered to external water baths or bench-top power supplies. Their limited capacity, usually only a few cages at once, further restricts their use, making them impractical in field settings or large insectaries where dozens of experimental crosses must be fed daily. Here we describe 3D-Feedy, an open-hardware, inexpensive membrane feeder that delivers electrically heated membrane feeding using simple, readily available parts. Powered via USB-C, including smartphone powerbanks, it is portable and straightforward to assemble with only basic tools and skills. In direct comparison with the widely used Hemotek feeder in Anopheles gambiae and Aedes albopictus, the 3D-Feedy achieved equal or higher feeding rates and significantly greater egg production while maintaining comparable larval hatching rates. These results validate 3D-Feedy as a practical and accessible tool for mosquito rearing and experimental studies. All design files and instructions are provided as open hardware resources.

zoology↗

bioRxiv2018

The host fruit amplifies mutualistic interactions between Ceratitis capitata larvae and associated bacteria.

Background:\n\nThe Mediterranean fruit fly Ceratitis capitata is a major pest in horticulture. The development of fly larvae is mediated by bacterial decay in the fruit tissue. Despite the importance of bacteria on larval development, very little is known about the interaction between bacteria and larvae in their true ecological context. Understanding their relationship and inter-dependence in the host fruit is important for the development of new pest control interfaces to deal with this pest.\n\nResults:\n\nWe find no negative effects on egg hatch or larval development brought about by the bacterial isolates tested. The various symbionts inhabiting the flys digestive system differ in their degree of contribution to the development of fly larvae depending on the given host and their sensitivity to induced inhibition caused by female produced antimicrobial peptides. These differences were observed not only at the genus or species level but also between isolates of the same species. We demonstrate how the microbiota from the mothers gut supports the development of larvae in the fruit host and show that larvae play a major role in spreading the bacterial contagion in the infected fruit itself. In addition, we present (for the first time) evidence for horizontal transfer of bacteria between larvae of different maternal origin that develop together in the same fruit.\n\nConclusions:\n\nLarvae play a major role in the spread and shaping of the microbial population in the fruit. The transfer of bacteria between different individuals developing in the same fruit suggests that the infested fruit serves as a microbial hub for the amplification and spread of bacterial strains between individuals.

ecology↗