Project description:Geographical and host plant influences on transcriptional variation in Drosophila mojavensis: mapping gene expression differences in both sexes
Project description:Investigation of whole genome transcription expression level changes in Drosophila mojavensis wild-type populations (1 Punta Onah: PO, 2 Organ Pipe National Monument: OPNM, 3 Punta Prieta:PP, and 4 San Quintin: SQ). The experiment was designed to investigate functional genomic responses to temperature variation (15, 25, and 35 °C) in adult Drosophila mojavensis wild populations. For each treatment 1-5 replicates were used (R1, R2, R3, R4 & R5). SO and BC represents Sonora deserts and Baja California region respectively.
Project description:In the presence of environmental change, natural selection can shape the transcriptome. Under a scenario of environmental change, genotypes that are better able to modulate gene expression to maximize fitness will tend to be favored. Therefore, it is important to examine gene expression at the population level in order to distinguish random or neutral gene expression variation from the pattern produced by natural selection. This study investigates the natural variation in transcriptional response to a cactus host shift utilizing the mainland Sonora population of Drosophila mojavensis. Drosophila mojavensis is a cactophilic species composed of four cactus host populations endemic to the deserts of North America. Overall, the change in cactus host was associated with a significant reduction in larval viability, as well as the differential expression of 21% of the genome (3,109 genes). Among the genes identified were a set of genes previously known to be involved in xenobiotic metabolism, as well as genes involved in cellular energy production, oxidoreductase/carbohydrate metabolism, structural components and mRNA binding. Interestingly, of the 3,109 genes whose expression was affected by host use, there was a significant overrepresentation of genes that lacked an orthologous call to the D. melanogaster genome, suggesting the possibility of an accelerated rate of evolution in these genes. Of the genes with a significant cactus effect, the majority, 2,264 genes, did not exhibit a significant cactus-by-line interaction. This population level approach facilitated the identification of genes involved in past cactus host shifts. Dataset from Population transcriptomics of cactus host shifts in Drosophila mojavensis, Matzkin, LM. Molecular Ecology.
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 preadult life history affects over adult transcriptome expression.
Project description:Investigation of whole genome transcription expression level changes in Drosophila mojavensis wild-type populations (1 Punta Onah: PO, 2 Organ Pipe National Monument: OPNM, 3 Punta Prieta:PP, and 4 San Quintin: SQ). The experiment was designed to investigate functional genomic responses to temperature variation (15, 25, and 35 °C) in adult Drosophila mojavensis wild populations. For each treatment 1-5 replicates were used (R1, R2, R3, R4 & R5). SO and BC represents Sonora deserts and Baja California region respectively. A total of 97 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 four populations (Punta Onah:PO; Organ Pipe National Manument:OPNM, Punta Prieta:PP and San Quintin:SQ), two host diets (Agria:AG and Organ pipe:OP) and three temperature treatments (15, 25 and 35 °C). Each chip measures the expression level of 14528 transcripts. One to 5 replicates were used for each type (R1, R2, R3, R4 and R5). Fly source details are as follows: Punta Onah 2007:PO07; Organ Pipe National Monument 2008:OPNM08; Punta Prieta 2008:PP08; San Quintin 2008:SQ08.
Project description:Geographical and host plant influences on transcriptional variation in Drosophila mojavensis: mapping gene expression differences in both sexes. (1. Punta Onah:PO07; 2. Organ Pipe National Monument:OPNM08; 3. Punta Prieta:PP08; & 4. San Quintin:SQ08). The experiment was designed to investigate effects of host plant (diet), mating status (mated:M or nonmated:V) and sex (male:male or Female:F) on transcriptome.
Project description:Local adaptation can play a fundamental role in the isolation of populations. While less well-studied than differentiation in sequence variation, changes in transcriptional variation during speciation also are fundamental to the evolutionary process. Drosophila mojavensis offers an unprecedented opportunity to examine the role of transcriptional differentiation in local adaptation. Drosophila mojavensis is a cactophilic fly composed of four ecologically distinct subspecies that inhabit the deserts of western North America. Each of the four subspecies utilizes necrotic tissue of different cactus host species characterized by distinct chemical profiles. The subspecies in Baja California, Mexico uses Stenocereus gummosus (Agria), in mainland Sonora it uses S. thurberi (Organ Pipe), in the Mojave Desert the host is Ferocactus cylindraceus (Red Barrel) and in Santa Catalina Island, USA, Opuntia littoralis (Prickly Pear) is the host. In this chapter we examine how the adaptation to the different environmental conditions across the four subspecies have shaped their transcriptional profiles. Using complete D. mojavensis genome microarrays we examined the transcriptome of third instar larvae from all four subspecies reared in standard laboratory media free of necrotic cactus-derived compounds. This experimental strategy focused on differences between constitutively expressed genes and not genes induced by necrotic cactus-derived compounds. The subspecies exhibited significant differential expression of genes that likely underlie the adaptation to different cactus hosts, such as detoxification genes (Glutathione S-transferases, Cytochrome P450s and UDP-Glycosyltransferases) and chemosensory genes (Odorant Receptors, Gustatory Receptors and Odorant Binding Proteins). Dataset from Matzkin, L. M. and Markow, T.A. Transcriptional differentiation across the four cactus host races of Drosophila mojavensis. In Speciation: Natural Processes, Genetics and Biodiversity. Edited by Michalak, P. Nova Science Publishers, Inc.
Project description:Migration is essential for the reproduction and survival of many animals, yet little is understood about its underlying molecular mechanisms. We used the salmonid Oncorhynchus mykiss to gain mechanistic insight into smoltification, which is a morphological, physiological, and behavioral transition undertaken by some juveniles that culminates in a seaward migration. This species is experimentally tractable and, unlike common model species, displays intra- and inter-population variation in migration propensity. Migratory individuals can produce non-migratory progeny and vice versa, indicating a high degree of phenotypic plasticity. One potential way that phenotypic plasticity might be linked to variation in migration-related life history tactics is through epigenetic regulation of gene expression. To explore this, we quantitatively measured genome-scale DNA methylation in fin tissue using reduced representation bisulfite sequencing of F2 siblings produced from a cross between steelhead (migratory) and rainbow trout (non-migratory) lines. We identified 57 differentially methylated regions (DMRs) between smolt and resident O. mykiss juveniles. DMRs were of high magnitude, ranging from 20-62% differential methylation between life history types, and over half of the gene-associated DMRs were in transcriptional regulatory regions. Many of the DMRs encode proteins with activity relevant to migration-related transitions (e.g. circadian rhythm pathway, nervous system development, protein kinase activity). This study provides the first evidence of a relationship between epigenetic variation and life history divergence associated with a migration-related transition in any species. Comparing global DNA methyldation profiles (via RRBS) of resident and smolt O. mykiss siblings using caudal fin tissue.