TheAedes aegyptilarval transcriptome: a comparative perspective with emphasis on trypsins and the domain structure of peritrophins
| Autor: | Clélia Ferreira, Sergio Verjovski-Almeida, Thiago M. Venancio, Walter R. Terra, Plinio T. Cristofoletti |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Glycosylation
animal structures Gene prediction Aedes aegypti Biology Aedes Genetics Melanogaster Animals Trypsin Molecular Biology Gene Phylogeny Expressed sequence tag Gene Expression Profiling fungi Gene Expression Regulation Developmental Midgut biology.organism_classification Molecular biology Protein Structure Tertiary Drosophila melanogaster Ion homeostasis Larva Insect Science Insect Proteins |
| Zdroj: | Insect Molecular Biology. 18:33-44 |
| ISSN: | 1365-2583 0962-1075 |
| Popis: | The genome sequence of Aedes aegypti was recently reported. A significant amount of Expressed Sequence Tags (ESTs) were sequenced to aid in the gene prediction process. In the present work we describe an integrated analysis of the genomic and EST data, focusing on genes with preferential expression in larvae (LG), adults (AG) and in both stages (SG). A total of 913 genes (5.4% of the transcript complement) are LG, including ion transporters and cuticle proteins that are important for ion homeostasis and defense. From a starting set of 245 genes encoding the trypsin domain, we identified 66 putative LG, AG, and SG trypsins by manual curation. Phylogenetic analyses showed that AG trypsins are divergent from their larval counterparts (LG), grouping with blood-induced trypsins from Anopheles gambiae and Simulium vittatum. These results support the hypothesis that blood-feeding arose only once, in the ancestral Culicomorpha. Peritrophins are proteins that interlock chitin fibrils to form the peritrophic membrane (PM) that compartmentalizes the food in the midgut. These proteins are recognized by having chitin-binding domains with 6 conserved Cys and may also present mucin-like domains (regions expected to be highly O-glycosylated). PM may be formed by a ring of cells (type 2, seen in Ae. aegypti larvae and Drosophila melanogaster) or by most midgut cells (type 1, found in Ae. aegypti adult and Tribolium castaneum). LG and D. melanogaster peritrophins have more complex domain structures than AG and T. castaneum peritrophins. Furthermore, mucin-like domains of peritrophins from T. castaneum (feeding on rough food) are lengthier than those of adult Ae. aegypti (blood-feeding). This suggests, for the first time, that type 1 and type 2 PM may have variable molecular architectures determined by different peritrophins and/or ancillary proteins, which may be partly modulated by diet. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|