Mutations in the desat1 gene reduces the production of courtship stimulatory pheromones through a marked effect on fatty acids in Drosophila melanogaster.
ABSTRACT In Drosophila melanogaster, desat1 is involved in the synthesis of fatty acids (FAs), some of which are precursors in the production of unsaturated hydrocarbons (HCs) in position 7 (7-HC) that play an important role in mating behaviour. Three GS lines with P-element insertion in the desat1 promoter showed more or less decrease in 7-HC, depending on the site of insertion. The forced transcription of genomic 5'P-flanking sequence led to opposite effects upon 7-HC, depending on the orientation of the insertions. Homozygous GS12251 flies showed particularly low 7-HC levels and severely affected courtship parameters (courtship latency doubled, number of copulation attempts decreased by half). After transposon excision, the HC phenotype was reversed in most lines, showing that the location of the transposon was responsible for the mutant phenotype. In homozygous GS12251 flies, the amounts of FAs and desat1 transcripts were reduced by half, compared to the amounts in heterozygous or wild-type flies. Relative proportions among FAs were quite similar to those of wild-type, with the exception of a slight decrease in myristoleic, palmitoleic and vaccenic acid. As the reduction of desat1 activity in the mutant resulted in a large decrease in both unsaturated and saturated FAs, it could impair FA and lipid metabolism, as it is known in vertebrates.
- SourceAvailable from: Jennifer L Watts[Show abstract] [Hide abstract]
ABSTRACT: Polyunsaturated fatty acids (PUFAs) exhibit a diverse range of critical functions in biological systems. PUFAs modulate the biophysical properties of membranes and, along with their derivatives, the eicosanoids and endocannabinoids, form a wide array potent lipid signaling molecules. Much of our early understanding of PUFAs and PUFA-derived signaling stems from work in mammals; however, technological advances have made comprehensive lipid analysis possible in small genetic models such as Caenorhabditis elegans and Drosophila melanogaster. These models have a number of advantages, such as simple anatomy and genome-wide genetic screening techniques, which can broaden our understanding of fatty-acid derived signaling in biological systems. Here we review what is known about PUFAs, eicosanoids, and endocannabinoids in the development and reproduction of C. elegans and D. melanogaster. Fatty acid signaling appears to be fundamental for multicellular organisms, and simple invertebrates often employ functionally similar pathways. In particular, studies in C. elegans and Drosophila are providing insight into the roles of PUFAs and PUFA-derived signaling in early developmental processes, such as meiosis, fertilization, and early embryonic cleavage. Mol. Reprod. Dev. © 2013 Wiley Periodicals, Inc.Molecular Reproduction and Development 02/2013; · 2.81 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Upon encountering a conspecific in the wild, males have to rapidly detect, integrate and process the most relevant signals to evoke an appropriate behavioral response. Courtship and aggression are the most important social behaviors in nature for procreation and survival: for males, making the right choice between the two depends on the ability to identify the sex of the other individual. In flies as in most species, males court females and attack other males. Although many sensory modalities are involved in sex recognition, chemosensory communication mediated by specific molecules that serve as pheromones plays a key role in helping males distinguish between courtship and aggression targets. The chemosensory signals used by flies include volatile and non-volatile compounds, detected by the olfactory and gustatory systems. Recently, several putative olfactory and gustatory receptors have been identified that play key roles in sex recognition, allowing investigators to begin to map the neuronal circuits that convey this sensory information to higher processing centers in the brain. Here, we describe how Drosophila melanogaster males use taste and smell to make correct behavioral choices.Journal of Comparative Physiology 09/2013; · 1.86 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Chrysomya megacephala (Fabricius), a prevalent necrophagous blowfly that is easily mass reared, is noted for being a mechanical vector of pathogenic microorganisms, a pollinator of numerous crops, and a resource insect in forensic investigation in the postmortem interval. In the present study, in order to comprehensively understand the physiological and biochemical functions of C. megacephala, we performed RNA-sequencing and digital gene expression (DGE) profiling using Solexa/Illumina sequencing technology. A total of 39,098,662 clean reads were assembled into 27,588 unigenes with a mean length of 768 nt. All unigenes were searched against the Nt database, Nr database, Swiss-Prot, Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genome (KEGG) with the BLASTn or BLASTx algorithm (E-value<0.00001) for annotations. In total, 7,081 unigenes and 14,099 unigenes were functionally classified into 25 COG categories and 240 KEGG pathways, respectively. Furthermore, 20,216 unigenes were grouped into 48 sub-categories belonging to 3 main Gene Ontology (GO) categories (ontologies). Using the transcriptome data as references, we analyzed the differential gene expressions between a soybean oil-fed group (SOF) and a lard oil-fed group (LOF), compared to the negative control group (NC), using the DGE approach. We finally obtained 1,566 differentially expressed genes in SOF/NC, and 1,099 genes in LOF/NC. For further analysis, GO and KEGG functional enrichment were performed on all differentially expressed genes, and a group of differentially expressed candidate genes related to lipometabolism were identified. This study provides a global survey of C. megacephala and provides the basis for further research on the functional genomics of this insect.PLoS ONE 01/2013; 8(5):e63168. · 3.53 Impact Factor