Biomedical subjects

Anupama Dahanukar

Publications and source records attributed to Anupama Dahanukar.

4 recordsLinked to original sources

PubMed2006

Insect odor and taste receptors.

Insect odor and taste receptors are highly sensitive detectors of food, mates, and oviposition sites. Following the identification of the first insect odor and taste receptors in Drosophila melanogaster, these receptors were identified in a number of other insects, including the malaria vector mosquito Anopheles gambiae; the silk moth, Bombyx mori; and the tobacco budworm, Heliothis virescens. The chemical specificities of many of the D. melanogaster receptors, as well as a few of the A. gambiae and B. mori receptors, have now been determined either by analysis of deletion mutants or by ectopic expression in in vivo or heterologous expression systems. Here we discuss recent advances in our understanding of the molecular and cellular basis of odor and taste coding in insects.

Animals↗

PubMed2005

Growth and cell survival are unevenly impaired in pixie mutant wing discs.

It is largely unknown how growth slows and then stops in vivo. Similar to most organs, Drosophila imaginal discs undergo a fast, near-exponential growth phase followed by a slow growth phase before final target size is reached. We have used a genetic approach to study the role of an ABC-E protein, Pixie, in wing disc growth. pixie mutants, like mutants in ribosomal proteins genes (known as Minutes), show severe developmental delay with relatively mild alterations in final body size. Intriguingly, pixie mutant wing imaginal discs show complex regional and temporal defects in growth and cell survival that are compensated to result in near-normal final size. In S2 cells, Pixie, like its yeast homolog RLI1, is required for translation. However, a comparison of the growth of eukaryotic translation initiation factor eIF4A and pixie mutant clones in wing discs suggests that only a subset of translation regulators, including pixie, mediate regional differences in growth and cell survival in wing discs. Interestingly, some of the regional effects on pixie mutant clone growth are enhanced in a Minute background. Our results suggest that the role of Pixie is not merely to allow growth, as might be expected for a translation regulator. Instead, Pixie also behaves as a target of putative constraining signals that slow disc growth during late larval life. We propose a model in which a balance of growth inhibitors and promoters determines tissue growth rates and cell survival. An alteration in this balance slows growth before final disc size is reached.

ATP-Binding Cassette Transporters↗

PubMed2005

Insect chemoreception.

Insect chemoreception is mediated by a large and diverse superfamily of seven-transmembrane domain receptors. These receptors were first identified in Drosophila, but have since been found in other insects, including mosquitoes and moths. Expression and functional analysis of these receptors have been used to identify receptor ligands and to map receptors to functional classes of neurons. Many receptors detect general odorants or tastants, whereas some detect pheromones. The non-canonical receptor Or83b, which is highly conserved across insect orders, dimerizes with odorant and pheromone receptors and is required for efficient localization of these proteins to dendrites of sensory neurons. These studies provide a foundation for understanding the molecular and cellular basis of olfactory and gustatory coding.

Animals↗

PubMed2003

Drosophila Gr5a encodes a taste receptor tuned to trehalose.

Recent studies have suggested that Drosophila taste receptors are encoded by a family of G protein-coupled receptor genes comprising at least 56 members. One of these genes, Gr5a, has been shown by genetic analysis to be required by the fly for behavioral and sensory responses to a sugar, trehalose. Here, we show that Gr5a is expressed in neurons of taste sensilla located on the labellum and legs. Expression is observed in most if not all labellar sensilla and suggests that many taste neurons express more than one receptor. We demonstrate by heterologous expression in a Drosophila S2 cell line that Gr5a encodes a receptor tuned to trehalose. This is the first functional expression of an invertebrate taste receptor.

Animals↗