Ricostruzione ultrastrutturale dell'apparato pungitore nelle zanzare e meccanismi bio-molecolari del pasto ematico

The evolutionary success of insects is due to their extraordinary morphological variability, with highly spe- cialized mouthparts reflecting the dietary needs of each species. This diversity allows insects to occupy different ecological niches. In the case of mosquitoes, the proboscis plays a key role in the blood meal. During metamor- phosis, larvae develop in water with chewing mouthparts, while adults have a biting-sucking proboscis to feed on nectar and blood. Mosquitoes can transmit pathogens during blood feeding, making the study of the morphology and function of the mouthparts crucial for the development of control strategies. X-ray microcomputed tomography is a useful tool for studying the anatomy of the mouthparts of mosquitoes. This technique allows the visualization of the internal tissues and the three-dimensional reconstruction of the struc- tures, providing detailed information on the development of the mouthparts. To understand how the blood meal works, the knowledge of the structure of the proboscis is not sufficient, but we need to comprehend the role of the substances injected by the insect during the process. Mosquito saliva, a com- plex mixture of proteins, plays a crucial role in facilitating blood feeding. Biomolecular interactions during feeding include modulation of the host immune system and facilitation of blood vessel localization. Specifically, a salivary protein called LIPS-2 from the tiger mosquito Aedes albopictus affects blood feeding behavior. Inhibition of this protein showed a slowdown in the skin perforation process, highlighting its role in enhancing the efficacy of the blood meal. The interaction of LIPS-2 with the labrum, a part of the mouthparts, morphologically modifies this structure. This modification is mediated by the interaction of LIPS-2 with a cuticular protein (Cp19). Understanding the process of stylet development and the molecular interactions between salivary proteins and the cuticle can provide further insight into the biochemical and physiological mechanisms involved in mosquito blood feeding.