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Biology subjects

Massani, B. B.

Publications and source records attributed to Massani, B. B..

2 recordsLinked to original sources

Chemical probes to interrogate the extreme environment of mosquito larval guts

Mosquito control methods are vital for the spread of life-threatening illnesses such as dengue fever, malaria, and yellow fever. Vector control technologies must be selective to minimize deleterious effects to our ecosystem. Successful methods that control mosquito larva populations utilize the uniquely high alkaline nature of the midgut. Here, we present novel protected triazabutadienes (pTBD) which are deprotected under basic conditions of the larval midgut, releasing an aryl diazonium ion (ADI) that results in protein modification. The probes contain a bioorthogonal terminal alkyne handle, enabling a selective Cu-click reaction with an azido-fluorophore for quantification by SDS PAGE and visualization using fluorescence microscopy. A control TBD, unable to release an ADI, did not label the midgut. We envision our chemical probes will aid in the development of new selective mosquito control methods thus preventing the spread of mosquito-borne illnesses with minimal impact on other organisms in the ecosystem.

biochemistry↗

Characterization of essential eggshell proteins from Aedes aegypti mosquitoes

Up to 40% of the world population now live in areas where dengue mosquito vectors coexist with humans. Aedes aegypti are vectors for zoonotic diseases that affect hundreds of millions of individuals per year globally. We recently identified the eggshell organizing factor 1 (EOF1) protein using systematic RNA interference (RNAi) screening of mosquito lineage-specific genes. It was shown that eggs deposited by RNAi-EOF1 A. aegypti and A. albopictus mosquitoes were non-melanized, fragile, and contained nonviable embryos. Motivated by this discovery, we performed RNAi screening of eggshell proteins to determine putative downstream target proteins of intracellular EOF1. We identified several eggshell proteins as essential for eggshell formation in A. aegypti and characterized their phenotypes in detail by molecular and biochemical approaches. We found that Nasrat, Closca, and Polehole structural proteins, together with the Nudel serine protease, are indispensable for eggshell melanization and egg viability. While all four proteins are predominantly expressed in ovaries of adult females, Nudel mRNA expression is highly upregulated in response to blood feeding. Furthermore, we identified four secreted eggshell enzymes as important factors for controlling the processes of mosquito eggshell formation and melanization. These enzymes included three dopachrome converting enzymes and one cysteine protease. All eight characterized eggshell proteins were required for intact eggshell formation. However, their surface topologies in response to RNAi did not phenocopy the effect of RNAi-EOF1. Still, it remains unclear how EOF1 influences eggshell formation and melanization. The use of proteomic analysis of eggshell proteins from RNAi-EOF1 assisted in the identification of additional proteins that could be regulated in EOF1 deficient eggshells.

developmental biology↗