Highlight organism

Displaying 1 - 8 of 8

Anopheles stephensi

Image: 
Anopheles stephensi
Community contact: 
Jake Tu (Indian), Nora Besansky and Dan Neafsey (SDA-500)
Body: 

Range

Anopheles stephensi Liston is a major malaria vector with a geographical range from the Middle East through the Indian subcontinent and China. Throughout its natural range, Anopheles stephensi is an important vector for both Plasmodium falciparum and Plasmodium vivax. The strain used for this genome sequencing project is the Indian Wild Type strain originally established at the Walter Reed Army Institute of Research. It belongs to the "type" biological form and has a segregating 2Rb inversion.

Habitats

Larvae of An. stephensi breed in various artificial containers in homes and collections of water associated with construction sites and other industrial locations. In rural areas, An. stephensi larvae utilise fresh-water pools, stream margins and stream beds, catch basins, seepage canals, wells and domestic water-storage containers. Larvae have also been found in domestic wells, overhead water tanks, room coolers, cisterns and roof gutters in the city of Delhi, but greater numbers of larvae are typically found outdoors compared with indoors. Larvae of the mysorensis form (distinguishable by egg morphology) appear to exclusively inhabit stone pots and earthenware containers. In rural areas of Gujarat, An. stephensi is associated with canal-irrigated, non-irrigated and riverine villages all year round, but generally in low densities. In urban areas, An. stephensi is found throughout the year, but is most abundant in the summer months (between June and August), which coincides with the peak period of malaria transmission.

Resting and feeding preferences

An. stephensi is generally considered to be an endophilic and endophagic species even though it will bite outdoors during the warmer summer months due to greater outdoor activity of humans and domestic animals. This species rests primarily in temporary or poorly constructed human and animal shelters rather than brick structures. Outdoor blood-feeding activity varies seasonally, with females feeding later in the night during the summer months compared to the winter months. However, indoor biting frequencies of An. stephensi appear to show no marked seasonal variation during different months of the year. Blood-meal analyses of An. stephensi females collected in urban areas indicated an increased tendency to feed on humans rather than cattle and other indications of variable anthropophily have been observed, depending on the availability of alternative hosts.

Vectorial capacity

An. stephensi is recognised as an important vector of malaria in urban areas bordering the Persian Gulf, including western and northwestern India. There are three known forms of An. stephensi including the typical form which is an efficient vector of urban malaria, the intermediate form, which is typically found in rural villages and peri-urban areas, but very little is known about its vector status, and the mysorensis form which is restricted to rural areas with poor vectorial capacity due to its highly zoophilic behaviour. The mysorensis form is, however, considered an important vector in Iran.

This text was modified from Sinka ME et al. (2011) The dominant Anopheles vectors of human malaria in Asia-Pacific: occurrence data, distribution maps and bionomic précis Parasites & Vectors 4:89.

Short Name: 
astephensi
Organism taxonomy: 

Anopheles cluster sequencing underway

Samples are now in sequencing at the Broad Institute for the NHGRI/NIAID-supported project, Genome Analysis of Vectorial Capacity in Major Anopheles Vectors of Malaria Parasites.

Category: 
General

Anopheles darlingi

Body: 

Range

Anopheles darlingi is one of the most important vectors of malaria in the Neotropics (Mexico, Central and South America), with populations from southern Mexico to Argentina.

Habitat

An. darlingi is a riverine mosquito, generally confined to rural, lowland forested locations. Deforestation and other human driven environmental change can create habitats which are favourable, with An. darlingi reportedly found at higher densities in areas with limited forest cover than in those predominated by forest. The larval habitats of An. darlingi can be characterized as natural water bodies such as lagoons, lakes and particularly slow flowing streams or rivers with shaded, clear water associated with submersed vegetation such as bamboo roots from overhanging spiny bamboo. Larvae are encountered most frequently in patches of floating debris along river margins. There are examples of larvae being found in uncharacteristic locations, such as in slightly brackish water; in low numbers in turbid, polluted water (brick pits); and in abandoned gold mine dugouts in southern Venezuela, further suggesting a level of adaptability to areas altered by humans. Moreover, An. darlingi appears to be adapting to higher altitude habitats with specimens recently collected at altitudes above 800m in Venezuela, close to the Brazilian border (Roraima).

Resting and feeding preferences

An. darlingi tends to rest outdoors regardless of where it has taken its blood meal. Adults will bite throughout the night and the degree of endo- and exophagy of this species varies from one place to another as does its host preference. It has been suggested that the biting pattern of An. darlingi may represent an adaptation to human behaviour, for example, the all night activity of An. darlingi in the gold mining areas of southern Venezuela may be a response to the all night activity of the miners. Furthermore, a number of studies that report exophagy in this species may be linked to sites where indoor insecticide spraying is or has recently been used for vector control.

Vectorial capacity

An. darlingi is considered to be one of the most efficient malaria vectors in the Neotropical region.

Short Name: 
adarlingi
Organism taxonomy: 

Anopheles stephensi released

Anopheles stephensi Liston is a major malaria vector with a geographical range from the Middle East through the Indian subcontinent and China. Throughout its natural range, Anopheles stephensi is an important vector for both Plasmodium falciparum and Plasmodium vivax. Further, Anopheles stephensi can transmit Plasmodium knowlesi, a virulent parasite that is vectored from non-human primates to humans. The strain used for this genome sequencing project is the Indian Wild Type strain originally established at the Walter Reed Army Institute of Research. It belongs to the ''type'' biological form and has a segregating 2Rb inversion.

The genome assembly presented here is preliminary. It represents a whole genome shotgun assembly of Roche 454 sequences generated in the laboratories of Zhijian Tu and Igor Sharakhov at Virginia Tech, USA. Dr. Yogesh Shouche at the National Centre for Cell Science, India, is also involved in this collaborative effort. The assembly totals 158Mb of sequence in 33,024 contigs and 6,150 scaffolds. As this version of the assembly is being annotated by VectorBase, an improved assembly was obtained at Virginia Tech and this has been submitted it to GenBank. Future annotation refinement will be made using the new assembly.

Annotation of the Anopheles stephensi assembly was carried out by VectorBase using MAKER informed by protein similarities and 18K ESTs and both Illumina and Roche 454 RNA-seq transcriptomics data. The resulting gene set is preliminary and will be refined in the future.

Use of the data
As a public service to the biological research community, these data are being made available by the sequence producers before scientific publication. We elect to follow the NHGRI policy for Release and Database Deposition of Sequence Data (link): ''The producing laboratories intend to publish the sequence of the genome and certain large-scale analyses of the sequence in a timely manner. The sole exception to the unrestricted use of these unpublished data is that the data may not be used for the initial publication of the complete genome sequence assembly or other large-scale analyses. In this context, 'large-scale' refers to regions the size of the whole genome or individual chromosomes and examples of 'large-scale analyses' include identification of regions of evolutionary conservation across an entire genome and identification of complete sets of genomic features such as genes, repeat structures, GC content, etc. The producing laboratories will, however, be open to the possibility of collaboration on such assemblies or analyses.'' Any redistribution of the data should carry this notice.

The genome, transcripts and proteins sequences are now available from our VectorBase downloads page.

Category: 
Release

Initial release of Anopheles darlingi at VectorBase

The Anopheles darlingi genome and annotations have been included in the VB-2012-06 release:

The following data are currently available on the genome browser:

  • 11,430 transcripts
  • 48,277 exons
  • 84,550 protein features from InterProScan
  • repeats from Dust and RepeatMasker

Database cross references will be run for subsequence VectorBase release. Also RNA-seq data will be integrated in the form of BAM files.

Organisms: 
Category: 
General
lawson's picture

ncRNA predictions for Aedes aegypti

The ncRNA pipeline has been used to predict RNA genes from the Ae. aegypti Liverpool assembly AaegL2. This generated 1,658 predictions which have been included in the AaegL2.2 geneset.

Organisms: 
Category: 
General
lawson's picture

ncRNA predictions for Anopheles albimanus

The ncRNA pipeline has been used to predict RNA genes from the An. albimanus STECLA assembly AalbS1. This generated 424 predictions which have been included in the AalbS1.1 geneset.

Category: 
General
lawson's picture

ncRNA predictions for Anopheles arabiensis

The ncRNA pipeline has been used to predict RNA genes from the An. arabiensis Dongola assembly AaraD1. This generated 516 predictions which have been included in the AaraD1.1 geneset.

Category: 
General
Subscribe to Highlight organism