Fig. 1: desat1 knockdown of newly-emerged female mosquitoes leads to blood-induced lethality, reduced fecundity, and absence of the peritrophic matrix.

a Schematic of the experimental design. Female mosquitoes were injected with dsdesat1 or dsGFP (control) at either 18 h or 72 h post-eclosion (PE). After a 3-day recovery period, a blood meal was provided and mosquito survival was recorded. Pre- and post-blood-feeding survival of female mosquitoes injected with dsdesat1 or dsGFP at 18 h PE (b) and 72 h PE (c) (n = 40). Statistics were performed using the Log-rank (Mantel-Cox) test. Similar results were obtained from three biological repeats. d Average ovarian follicle size of females injected with dsdesat1 or dsGFP at different PE times. Ovaries from surviving females were dissected at 24 h post-blood meal (PBM), and lengths of 6 ovarian follicles per female were measured (n = 15). The follicles of female mosquitoes injected with dsdesat1 at 18 h PE underwent complete developmental arrest and were recorded as 0 μm. Similar results were obtained from two biological repeats. Violin plots display the full distribution: center line: median; upper/lower hinges: 75th and 25th percentiles. e Egg numbers per female at 3d PBM, comparing dsdesat1- and dsGFP-treated individuals at different PE stages (n = 18). Similar results were obtained from two biological repeats. f Representative images of whole mosquitoes and dissected midguts at 24 h PBM from females injected with dsGFP or dsdesat1 at 18 h PE. g Quantification of total midgut bacteria at 24 h PBM in mosquitoes injected with dsdesat1 at 18 h PE (see panel a). h Transmission electron microscope (TEM) images of midguts dissected from sugar-fed mosquitoes and at 24 h PBM following dsGFP or dsdesat1injection at 18 h PE. Scale bars on the left and center panels = 2 μm; the right panel shows an enlarged view of the center images with scale bars = 1 μm. EC, epithelial cell; Mv, microvilli; PM, peritrophic matrix; BM, blood meal; Nu, nucleus; Sr, storage reservoir with several granules; Mt, mitochondrion. All error bars represent SEM. In d and g, statistics were performed with Student’s t test. In e, significant difference was analyzed using the Mann-Whitney test. *, p < 0.05; ***, p < 0.001, ****, p < 0.0001. Source data are provided as a Source Data file.