Aedes aegypti Assembly and Gene Annotation
About Aedes aegypti
Aedes aegypti exists in at least two forms (considered either subspecies or separate species according to different authors), namely Ae. aegypti formosus (the original wild type found in Africa) and Ae. aegypti aegypti (the worldwide urban form). The yellow fever mosquito, Ae. aegypti aegypti, has a worldwide distribution in the tropics and subtropics where it is the main vector of both dengue and yellow fever viruses.
Picture credit (public domain): James Gathany (CDC) 2006
The Aedes aegypti Liverpool LVP strain genome sequence is a joint effort between the Broad Institute and The Institute for Genomic Research (TIGR) . Assembly of 8x shotgun coverage was performed using the Broad's whole genome assembly package ARACHNE. The assembly presented here (AaegL3) consists of 4,756 supercontigs and a mitochondrial chromosome, totalling 1.3 gigabases.
The initial annotation of the Aedes aegypti genome is a collaboration between VectorBase and TIGR. Each group generated a set of gene predictions which were merged into a single canonical set (AaegL1.1). The geneset presented here (AaegL3.1, April 2014) represents the original set integrated with several rounds of community annotations; additional gene predictions that were excluded from the AaegL1.1 set but subsequently found to have supporting evidence (transcriptome, mapped protein domains); mitochondrial genes; and non-coding RNA genes from the Ensembl Genomes pipeline.
Starting with Ensembl Genomes release 23, SNP data is available for Aedes aegypti, derived from the Bonizzoni et al. study  and imported via VectorBase. The study used RNA-seq to characterise sequence variation in three laboratory strains of Aedes aegypti. An analysis of the transcriptomes from the Liverpool (LVP) reference strain, and two strains that exhibit differential susceptibility to Dengue-2 infection (Chetumal and Rexville D-Puerto Rico) was conducted, identifying many novel transcriptional units and polymorphisms in immunity related genes.
EST and Protein Alignments
WU-BlastX was used to map UniProtKB proteins onto the Aedes aegypti genome. The datasets used were: Aedes, mosquito, drosophilid, arthropod, metazoan, eukaryotic, and non-eukaryotic proteins. The wider taxonomic groups exclude any of the more specific groups, e.g. the arthropod dataset excludes mosquito and drosophilid proteins. (Example: supercont1.174:147000-580000).
Approximately 1300 community annotations are mapped to the genome (Example: supercont1.174:147000-580000).
- Genome sequence of Aedes aegypti, a major arbovirus vector.
Nene V, Wortman JR, Lawson D, Haas B, Kodira C, Tu ZJ, Loftus B, Xi Z, Megy K, Grabherr M et al. 2007. Science. 316:1718-1723.
- Probing functional polymorphisms in the dengue vector, Aedes aegypti.
Bonizzoni M, Britton M, Marinotti O, Dunn WA, Fass J, James AA. 2013. BMC Genomics. 14:739.
|Assembly:||AaegL3, INSDC Assembly GCA_000004015.1, Dec 2013|
|Golden Path Length:||1,383,974,186|
|Genebuild method:||Full genebuild|
Genes and/or transcript that contains an open reading frame (ORF).:
|Small non coding genes:||1,476|
|Long non coding genes
Long non coding genes are usually greater than 200 bases long. They may be transcribed but are not translated. In Ensembl, genes with the following biotypes are classed as long non coding genes: 3prime_overlapping_ncrna, ambiguous_orf, antisense, antisense_RNA, lincRNA, ncrna_host, non_coding, non_stop_decay, processed_transcript, retained_intron, sense_intronic, sense_overlapping. The majority of the long non coding genes in Ensembl are annotated manually by HAVANA.:
A pseudogene shares an evolutionary history with a functional protein-coding gene but it has been mutated through evolution to contain frameshift and/or stop codon(s) that disrupt the open reading frame.:
|Gene transcriptsNucleotide sequence resulting from the transcription of the genomic DNA to mRNA. One gene can have different transcripts or splice variants resulting from the alternative splicing of different exons in genes.:||18,838|