A dengue receptor as possible genetic marker of vector competence in Aedes aegypti

Abstract

Background: Vector competence refers to the intrinsic permissiveness of an arthropod vector for infection, replication and transmission of a virus. Notwithstanding studies of Quantitative Trait Loci (QTL) that influence the ability of Aedes aegypti midgut (MG) to become infected with dengue virus (DENV), no study to date has been undertaken to identify genetic markers of vector competence. Furthermore, it is known that mosquito populations differ greatly in their susceptibility to flaviviruses. Differences in vector competence may, at least in part, be due to the presence of specific midgut epithelial receptors and their identification would be a significant step forward in understanding the interaction of the virus with the mosquito. The first interaction of DENV with the insect is through proteins in the apical membrane of the midgut epithelium resulting in binding and receptormediated endocytosis of the virus, and this determines cell permissiveness to infection. The susceptibility of mosquitoes to infection may therefore depend on their specific virus receptors. To study this interaction in Ae. aegypti strains that differ in their vector competence for DENV, we investigated the DS3 strain (susceptible to DENV), the IBO-11 strain (refractory to infection) and the membrane escape barrier strain, DMEB, which is infected exclusively in the midgut epithelial cells.

Larval Environmental Temperature and the Susceptibility ofAedes albopictusSkuse (Diptera: Culicidae) to Chikungunya Virus

“…Vector competence, which is the capacity of an arthropod to acquire an infection and transmit it to a subsequent host, can greatly vary among individuals and between populations (Lorenz et al 1984, Turell et al 1992 and is influenced by genetics (Mercado-Curiel et al 2008) as well as by climate variables, such as temperature (Davis 1932, Turell 1993, Dohm et al 2002). An increase in environmental temperature for adult mosquitoes reduces the EIP (Davis 1932, Chamberlain andSudia 1955), most likely due to an increase in the metabolism of the adult mosquito and the replication speed of the virus.…”

Can Horton Hear the Whos? The Importance of Scale in Mosquito-Borne Disease

“…For example, recent studies have shown that an individual mosquito’s susceptibility to infection with a pathogen can be affected by small changes in environmental factors (e.g., Kilpatrick et al 2008, Richards et al 2009) and within-individual factors (e.g., binding of viruses to midgut proteins, Mercado-Curiel et al 2008), likely influencing population- and species-level variation in vector competence. However, how this individual variation affects transmission dynamics beyond the individual level is not known.…”

Dengue Virus Cellular Receptors and Tropism

“…Interestingly, the presence of the 67 kDa protein in midgut cells of three varieties of Ae. aegypti mosquitoes correlated with their susceptibility to DENV infection, thus, it has been proposed as a vector competence marker [95]. Finally, proteins ranging in molecular weight from 77 to 37 kDa obtained from Ae.…”