Iron and Ferritin Deposition in the Ovarian Tissues of the Yellow Fever Mosquito (Diptera: Culicidae)

Abstract

Dengue, yellow fever, and Zika are viruses transmitted by yellow fever mosquito, Aedes aegypti [Linnaeus (Diptera: Culicidae)], to thousands of people each year. Mosquitoes transmit these viruses while consuming a blood meal that is required for oogenesis. Iron, an essential nutrient from the blood meal, is required for egg development. Mosquitoes receive a high iron load in the meal; although iron can be toxic, these animals have developed mechanisms for dealing with this load. Our previous research has shown iron from the blood meal is absorbed in the gut and transported by ferritin, the main iron transport and storage protein, to the ovaries. We now report the distribution of iron and ferritin in ovarian tissues before blood feeding and 24 and 72 h post-blood meal. Ovarian iron is observed in specific locations. Timing post-blood feeding influences the location and distribution of the ferritin heavy-chain homolog, light-chain homolog 1, and light-chain homolog 2 in ovaries. Understanding iron deposition in ovarian tissues is important to the potential use of interference in iron metabolism as a vector control strategy for reducing mosquito fecundity, decreasing mosquito populations, and thereby reducing transmission rates of vector-borne diseases.

Mosquito metallomics reveal copper and iron as critical factors for Plasmodium infection

“…Ae . aegypti embryos show, as expected [ 24 , 25 ], substantive accumulation of iron, averaging at 0.38 mg per g dry weight, however An . albimanus embryos only accumulated 0.05 mg per g dry weight ( Fig 2A ).…”

“…Likewise, iron chelation's additive inhibitory effect on oogenesis observed in both ws and bs phenotypes were not unexpected given what is known for the role of iron in oogenesis in Ae. aegypti [24,25]. Two further findings are presented here.…”

“…This result is consistent with the previously shown requirement of iron for oogenesis in Ae . aegypti [ 24 , 25 ]. Each individual female either had fully-developed or immature ovaries, meaning that the response was of an "all-or-none" type ( S3 Fig ).…”

“…This result is consistent with the previously shown requirement of iron for oogenesis in Ae. aegypti [24,25]. Each individual female either had fully-developed or immature ovaries, meaning that the response was of an "all-or-none" type (S3 Fig) . In contrast to iron, copper availability did not alter follicular development in response to infection, as judged from the application of BCS to either phenotype (Fig 4A; p = 0.287 for ws and p = 0.076 for bs comparisons, respectively).…”

“…In Ae . aegypti , the fate of blood meal iron was traced showing iron accumulation in female ovaries [ 24 , 25 ]. It is also worth noting that Wolbachia interferes with insect iron metabolism [ 26 , 27 ].…”