Figure 1.
Intravital micrographs illustrating different steps in the blood meal.
A and B: flexibility of the labrum; C: mouthparts within the skin, showing the labrum and maxillae in particular; D: damage due to the passage of the proboscis through a blood vessel during probing, triggering blood extravasation.
Figure 2.
Intravital micrographs illustrating probing with salivation.
Series of bubbles were observed at each movement of the proboscis (A to D), as shown by arrows.
Figure 3.
Intravital micrographs showing different blood meal types.
A: The proboscis is inserted into the blood vessel and follows its lumen; B, C, D and E: the proboscis is inserted perpendicular to the blood vessel. The images were recorded at several time points after the start of blood feeding. The strength of suction decreases over time, as demonstrated by the gradual increase in blood vessel diameter until withdrawal of the proboscis; F and G: illustration of two types of pool feeding. In F, the proboscis is located in the pool of blood, whereas in G, the proboscis is sucking up blood from a blood pool some distance away. The proboscis is showed by an arrow.
Table 1.
Influence of female mosquito's age on various parameters of probing and blood feeding observed using intravital microscopy.
Table 2.
Role of Plasmodium berghei infection on probing and blood meal of Anopheles gambiae using the second protocol.
Figure 4.
Intravital micrograph of a blood vessel after blood feeding.
The mouse was immunized with saliva. A white area enlarged around the tip of the proboscis and remained visible after the withdrawal of the mouthparts.
Table 3.
Comparison between mosquitoes feeding on saliva-immunized and non-immunized mice.
Table 4.
Comparison between the various types of immunization.
Figure 5.
Intravital fluorescence micrograph showing several deposits of sporozoites in the mouse skin.
A: Global view of mouse skin bitten by a mosquito infected with GFP-labeled sporozoites. Small arrows indicate sporozoite deposits; B and C: enlargement of two pools of sporozoites indicated by large arrows.
Figure 6.
Local tissue damage on the inner surface of the skin after uninfected mosquito bites.
Mice were exposed to the bites of 50 mosquitoes for 15 minutes and were killed at various time points: A) 1 h; B) 3 h; C) 5 h; D) 8 h; E) 24 h; F) control. Thirty minutes before the mice were killed, they were injected with Evans Blue, for the monitoring of capillary extravasation.
Figure 7.
Local tissue damage on the inner surface of the skin after Plasmodium berghei-infected mosquito bites.
Infected mosquitoes were selected by the visualization of fluorescent sporozoites in the salivary glands of cold-anesthetized insects under a fluorescence microscope. Mice were exposed to the bites of 50 infected mosquitoes for 15 minutes and killed at various time points: A) 1 h; B) 3 h; C) 16 h; D) 24 h; E) control. Thirty minutes before the mice were killed, they were injected with Evans Blue for the monitoring of capillary extravasation.
Figure 8.
Photomicrographs of skin sections and underlying tissues of naive mice bitten by uninfected Anopheles gambiae mosquitoes.
These observations were made on mice killed one hour after the bite. A, B, C: HE staining; D: Giemsa staining; B. The magnification was ×20 for A and B and ×40 for C and D.
Figure 9.
Observation of areas of hemorrhage at high magnification.
Skin sections from mice killed at the times indicated were stained with HE 1 h (A), 3 h (B), 8 h (C) and 24 h (D) after the bite. Magnification ×100.
Figure 10.
Localization of saliva in the dermis of mice bitten by Anopheles gambiae.
Saliva was detected with rabbit anti-saliva antibodies 30 minutes, 1 h, 3 h and 18 h after the bite. A: Giemsa staining, B: saliva staining. Magnification: ×20.
Figure 11.
Localization of polynuclear cells and saliva in the dermis.
Saliva was detected with rabbit anti-saliva antibodies A) 30 minutes, B) 1 h, and C) 3 h Saliva was stained with rabbit anti-saliva antibodies. Magnification: ×40.
Figure 12.
Localization of mast cells (A) and sporozoites (B) on skin sections from mice bitten by Plasmodium berghei-infected mosquitoes.
Mast cells were localized by Giemsa staining 1 h after bite. Sporozoites were stained with a monoclonal anti-CS antibody. Magnification: ×40.
Figure 13.
Detection of sporozoites (A) and saliva (B) deposits in the dermis after Plasmodium berghei-infected mosquito bites.
Sporozoites were identified with a monoclonal anti-CSP antibody and saliva was characterized with rabbit anti-saliva antibodies. Magnification: ×40.