Project description:Investigation of whole genome transcription expression level changes in Drosophila mojavensis wild-type populations (Las Bocas:LB and Punta Prieta:PP). The experiment was designed to investigate life history transcriptomics in different environments.
Project description:Understanding the genetic basis of adaptation to novel environments remains one of the major challenges confronting evolutionary biologists. While newly developed genomic approaches hold considerable promise for addressing this overall question, the relevant tools have not often been available in the most ecologically interesting organisms. Our study organism, Drosophila mojavensis, is a cactophilic Sonoran Desert endemic utilizing four different cactus hosts across its geographic range. Its well-known ecology makes it an attractive system in which to study the evolution of gene expression during adaptation. As a cactophile, D. mojavensis oviposits in the necrotic tissues of cacti, therefore exposing larvae and even adults to the varied and toxic compounds of rotting cacti. We have developed a cDNA microarray of D. mojavensis to examine gene expression associated with cactus host use. Using a population from the Baja California population we examined gene expression differences of third instar larvae when reared in two chemically distinct cactus hosts, agria (Stenocereus gummosus, native host) vs. organpipe (S. thurberi, alternative host). We have observed differential gene expression associated with cactus host use in genes involved in metabolism and detoxification. Keywords: host adaptation, stress response, detoxification
Project description:Understanding the genetic basis of adaptation to novel environments remains one of the major challenges confronting evolutionary biologists. While newly developed genomic approaches hold considerable promise for addressing this overall question, the relevant tools have not often been available in the most ecologically interesting organisms. Our study organism, Drosophila mojavensis, is a cactophilic Sonoran Desert endemic utilizing four different cactus hosts across its geographic range. Its well-known ecology makes it an attractive system in which to study the evolution of gene expression during adaptation. As a cactophile, D. mojavensis oviposits in the necrotic tissues of cacti, therefore exposing larvae and even adults to the varied and toxic compounds of rotting cacti. We have developed a cDNA microarray of D. mojavensis to examine gene expression associated with cactus host use. Using a population from the Baja California population we examined gene expression differences of third instar larvae when reared in two chemically distinct cactus hosts, agria (Stenocereus gummosus, native host) vs. organpipe (S. thurberi, alternative host). We have observed differential gene expression associated with cactus host use in genes involved in metabolism and detoxification. The experiment was composed of 5 sets of dye-flips (rep1-5). Larvae were reared in either necrotic agria or organpipe cactus tissues. They were then collected at the third instar stage and its total RNA extracted.
Project description:BACKGROUND:Drosophila mojavensis has been a model system for genetic studies of ecological adaptation and speciation. However, despite its use for over half a century, no linkage map has been produced for this species or its close relatives. RESULTS:We have developed and mapped 90 microsatellites in D. mojavensis, and we present a detailed recombinational linkage map of 34 of these microsatellites. A slight excess of repetitive sequence was observed on the X-chromosome relative to the autosomes, and the linkage groups have a greater recombinational length than the homologous D. melanogaster chromosome arms. We also confirmed the conservation of Muller's elements in 23 sequences between D. melanogaster and D. mojavensis. CONCLUSIONS:The microsatellite primer sequences and localizations are presented here and made available to the public. This map will facilitate future quantitative trait locus mapping studies of phenotypes involved in adaptation or reproductive isolation using this species.
Project description:Investigation of whole genome transcription expression level changes in Drosophila mojavensis wild-type populations (Las Bocas:LB and Punta Prieta:PP). The experiment was designed to investigate life history transcriptomics in different environments. A total of 172 hybridizations were performed in this entire experiment. We used 135K 12-plex NimbleGen arrays. Total RNA was recovered from each sample listed below. The experimental design consisted a total of two populations (Las Bocas:LB; Punta Prieta:PP), two host diets (Agria:AG and Organ pipe:OP) and fourteen life stages (6 hr egg:E6; 1st instar larvae:L1; 2nd instar larvae:L2; 3rd instar larvae:L3; Early pupal stage:EP; Late pupal stage:LP; 0 Day old adult:0D; 3 Day old adult:3D; 4 Day old adult: 4D; 6 Day old adult:6D; 10 Day old adult:10D; 14 Day old adult:14D; 18 Day old adult:18D & 24 Day old adult:24D). Each chip measures the expression level of 14528 transcripts. Two to 5 replicates were used for each type (R1, R2, R3 etc.). Fly source details are as follows: Las Bocas 2009: LB09; Punta Prieta 2008:PP08.
Project description:In Drosophila, adaptation to xeric environments presents many challenges, greatest among them the maintenance of water balance. Drosophila mojavensis, a cactophilic species from the deserts of North America, is one of the most desiccation-resistant in the genus, surviving low humidity primarily by reducing its metabolic rate. Genetic control of reduced metabolic rate, however, has yet to be elucidated. We utilized the recently sequenced genome of D. mojavensis to create an oligonucleotide microarray in order to pursue the identities of the genes involved in metabolic regulation during desiccation. We observed large differences in gene expression between male and female D. mojavensis as well as both quantitative and qualitative sex differences in their ability to survive xeric conditions. As expected, genes associated with metabolic regulation and carbohydrate metabolism were differentially regulated between stress treatments. Most importantly, we identified four points in central metabolism (Glyceraldehyde 3-phosphate dehydrogenase, transaldolase, alcohol dehydrogenase and phosphoenolpyruvate carboxykinase) that indicate the potential mechanisms controlling metabolic rate reduction associated with desiccation resistance. Furthermore, a large number of genes associated with vision pathways also were differentially expressed between stress treatments, especially in females, that may underlie the initial detection of stressful environments and trigger subsequent metabolic changes. Dataset from Transcriptional regulation of metabolism associated with the increased desiccation resistance of the cactophilic Drosophila mojavensis Matzkin,LM and Markow, MA, Genetics.