Anopheles gambiae
Encyclopedia
Anopheles gambiae is a complex
of at least seven morphologically distinguishable species of mosquitoes in the genus Anopheles
. This complex was recognised in the 1960s and includes the most important vectors of malaria
in sub-Saharan Africa
and the most efficient malaria
vectors known.
This species complex consists of:
Despite being morphologically
indistinguishable, individual species of Anopheles gambiae complex exhibit different behavioural traits. For example, the Anopheles quadriannulatus, is generally considered to be zoophilic, (taking its blood meal from animals) whereas Anopheles gambiae sensu stricto is generally anthropophilic (taking its blood meal from humans). Identification to the individual species level using the molecular methods of Scott et al. (1993) can have important implications in subsequent control measures.
Recently a new cryptic subgroup - the Goundry subgroup- of Anopheles gambiae sensu stricto has been described.
.
The mechanism of species recognition appears to be sounds emitted by the wings and identified by Johnston's organ
.
in 1930, which lead to a malaria epidemic in 1938/1939. The Brazilian government assisted by the Rockfeller Foundation in a programme spearheaded by Fredrick Soper eradicated these mosquitoes from this area. This effort was modeled on the earlier success in eradication of Aedes aegypti
elimination as part of the yellow fever
control program. The exact species involved in this epidemic has been identified as An. arabiensis.
Cryptic species complex
In biology, a cryptic species complex is a group of species which satisfy the biological definition of species—that is, they are reproductively isolated from each other—but whose morphology is very similar ....
of at least seven morphologically distinguishable species of mosquitoes in the genus Anopheles
Anopheles
Anopheles is a genus of mosquito. There are approximately 460 recognized species: while over 100 can transmit human malaria, only 30–40 commonly transmit parasites of the genus Plasmodium, which cause malaria in humans in endemic areas...
. This complex was recognised in the 1960s and includes the most important vectors of malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
in sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...
and the most efficient malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
vectors known.
This species complex consists of:
- Anopheles arabiensis
- Anopheles bwambae
- Anopheles merus
- Anopheles melas
- Anopheles quadriannulatus
- Anopheles gambiae sensu stricto
Despite being morphologically
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...
indistinguishable, individual species of Anopheles gambiae complex exhibit different behavioural traits. For example, the Anopheles quadriannulatus, is generally considered to be zoophilic, (taking its blood meal from animals) whereas Anopheles gambiae sensu stricto is generally anthropophilic (taking its blood meal from humans). Identification to the individual species level using the molecular methods of Scott et al. (1993) can have important implications in subsequent control measures.
Recently a new cryptic subgroup - the Goundry subgroup- of Anopheles gambiae sensu stricto has been described.
Anopheles gambiae in the strict sense
A. gambiae s.str. has been discovered to be currently in a state of diverging into two different species — the Mopti (M) and Savannah (S) strains — though as of 2007, the two strains are still considered to be a single species. The A. gambiae s.str. genome has been sequenced, though there is controversy over the choice of strain used, which is considered a hybrid of two different strains. Currently, ~90 miRNA have been predicted in the literature (38 miRNA officially listed in miRBase) for A. gambiae s.str. based upon conserved sequences to miRNA found in DrosophilaDrosophila
Drosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...
.
The mechanism of species recognition appears to be sounds emitted by the wings and identified by Johnston's organ
Johnston's organ
Johnston's organ is a collection of sensory cells found in the pedicel of the antennae in the Class Insecta. Johnston's organ detects motion in the flagellum . It consists of over 200 scolopidia arrayed in a bowl shape, each of which contains a mechanosensory chordotonal neuron...
.
Historical note
An. gambiense invaded northeastern BrazilBrazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
in 1930, which lead to a malaria epidemic in 1938/1939. The Brazilian government assisted by the Rockfeller Foundation in a programme spearheaded by Fredrick Soper eradicated these mosquitoes from this area. This effort was modeled on the earlier success in eradication of Aedes aegypti
Aedes aegypti
The yellow fever mosquito, Aedes aegypti is a mosquito that can spread the dengue fever, Chikungunya and yellow fever viruses, and other diseases. The mosquito can be recognized by white markings on legs and a marking in the form of a lyre on the thorax...
elimination as part of the yellow fever
Yellow fever
Yellow fever is an acute viral hemorrhagic disease. The virus is a 40 to 50 nm enveloped RNA virus with positive sense of the Flaviviridae family....
control program. The exact species involved in this epidemic has been identified as An. arabiensis.