Smartt, C. T. | bioRxiv Science

bioRxiv2022

Assessment of mosquito longevity, fecundity, and dengue virus titer following exposure to plasma from a host with Type 2 diabetes mellitus - a pilot study

The mosquito Aedes aegypti (Linnaeus) prefers feeding on humans and will encounter many blood components that might influence mosquito physiology and vectorial capacity. The effects of dengue virus infection in patients with type-2 diabetes mellitus revealed an influence on platelet numbers in blood and diabetic persons are more likely to develop severe dengue. Infection with dengue virus (DENV) is known to impact diabetic patients but the impact of diabetic blood on mosquito vectorial capacity is not known. This pilot study investigated the effects of ingesting blood plasma from a patient with diabetes on mosquito fecundity, longevity, and vector competence for DENV-2 in the mosquito, Ae. aegypti. Female mosquitoes fed on plasma from a diabetic individual laid significantly more eggs. Diabetic plasma shortened overall mosquito life span. Vector competence was significantly different between extrinsic incubation periods at 7 (3.44{+/-}2.5 log PFUe DENV) and 14 days post-infection (4.28{+/-}2.4 log PFUe DENV) in mosquitoes fed DENV-2 in plasma from a diabetic individual. As this study is an initial investigation into the influence of diabetes plasma on mosquito life history traits, a more comprehensive study with more samples of diabetes plasma is underway and should yield more details about the impact of diabetes on mosquito biology.

ecology↗

bioRxiv2017

Spatial and temporal distribution of genome divergence among California populations of Aedes aegypti.

In the summer of 2013, Aedes aegypti Linnaeus was first detected in three cities in central California (Clovis, Madera and Menlo Park). It has now been detected in multiple locations in central and southern CA as far south as San Diego and Imperial Counties. A number of published reports suggest that CA populations have been established from multiple independent introductions. Here we report the first population genomics analyses of Ae. aegypti based on individual, field collected whole genome sequences. We analyzed 46 Ae. aegypti genomes to establish genetic relationships among populations from sites in California, Florida and South Africa. We identified 3 major genetic clusters within California; one that includes all sample sites in the southern part of the state (South of Tehachapi mountain range) plus the town of Exeter in central California and two additional clusters in central California. A lack of concordance between mitochondrial and nuclear genealogies suggests that the three founding populations were polymorphic for two main mitochondrial haplotypes prior to being introduced to California. One of these has been lost in the Clovis populations, possibly by a founder effect. Genome-wide comparisons indicate extensive differentiation between genetic clusters. Our observations support recent introductions of Ae. aegypti into California from multiple, genetically diverged source populations. Our data reveal signs of hybridization among diverged populations within CA. Genetic markers identified in this study will be of great value in pursuing classical population genetic studies which require larger sample sizes.

genomics↗