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Lewin, A. R.

Publications and source records attributed to Lewin, A. R..

2 recordsLinked to original sources

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↗

An OpIE2-DsRed marker disrupts female blood-feeding and shortens lifespan in the malaria vector Anopheles gambiae.

Anopheles gambiae is one of the principal vectors of human malaria. Over the past two decades, transgenic mosquito strains have been essential tools for studying mosquito biology and developing genetic control strategies such as gene drives. Mosquito transformants are typically identified using fluorescent markers, which are assumed to be phenotypically neutral. While generating CRISPR-based gene drive strains carrying an OpIE2-DsRed marker we unexpectedly found that transgenic females were unable to blood-feed and were consequently sterile, whereas males initially appeared normal and fertile. Given the potential utility of dominant, female-specific sterility for mosquito control, we established additional strains controlling for transgene content and integration site, confirming that the OpIE2-DsRed cassette caused the defect. Behavioral assays showed that females exhibited normal attraction to a membrane feeder but failed to initiate blood-feeding, performing repeated cycles of probing and proboscis grooming in rapid succession before ultimately leaving the feeder unfed. Microscopy showed that both sexes possessed a distally curved proboscis, providing a morphological explanation for the blood-feeding defect of females and the reduced male lifespan. A second promoter variant (OpIE2b), differing in flanking sequences at the IE-2 junction, drove strong marker expression without impairing blood-feeding or longevity. These findings demonstrate that minor differences in promoter architecture can produce major, unexpected phenotypic effects. OpIE2b provides a robust, phenotypically neutral marker for An. gambiae research, while OpIE2a highlights the need for rigorous validation of transgenic components intended for research and applied releases.

genetics↗