ABSTRACT: D. yakuba, D. simulans, and D. sechellia gDNA competitively hybridized against D. melanogaster to evaluate aCGH as a means to identify diverged orthologs.
Project description:D. yakuba, D. simulans, and D. sechellia gDNA competitively hybridized against D. melanogaster to evaluate aCGH as a means to identify diverged orthologs. 2 D. sechellia vs D. melanogaster hybs - with dye swap, 2 D. simulans vs D. melanogaster hybs with dye swap, and 8 D. yakuba vs D. melanogaster hybs with balanced dye swaps. D. yakuba vs. D. melanogaster were then analyzed in all 2,4,6,8 possible combinations that incorporated dye-swap to asses sources of variation.
Project description:D. yakuba, D. simulans, and D. melanogaster female gDNA hybridized with D. melanogaster male gDNA to assess aCGH as a means of identification of duplicated genes
Project description:D. yakuba, D. simulans, and D. melanogaster female gDNA hybridized with D. melanogaster male gDNA to assess aCGH as a means of identification of duplicated genes 6 D. melanogaster female vs D. melanogaster male hybs, 6 D. simulans female vs D. melanogaster male hybs, and 4 D. yakuba female vs D. melanogaster male hybs, all with balanced dye swaps
Project description:We identified 6,975 insertion/deletion events of between 10 and 100 bp in length from the Drosophila simulans and Drosophila sechellia Mercator/MAVID genomic sequence alignment. Replicate pure samples of Drosophila simulans and Drosophila sechellia gDNA were competitively hybridized to measure the expected relative hybridization intensity of alleles from each species. We used these measured intensities to assess the likelihood that the hybridization signal at each probe in an experimental animal reflected homozygosity or heterozygosity at that locus.
Project description:We identified 6,975 insertion/deletion events of between 10 and 100 bp in length from the Drosophila simulans and Drosophila sechellia Mercator/MAVID genomic sequence alignment. Replicate pure samples of Drosophila simulans and Drosophila sechellia gDNA were competitively hybridized to measure the expected relative hybridization intensity of alleles from each species. We used these measured intensities to assess the likelihood that the hybridization signal at each probe in an experimental animal reflected homozygosity or heterozygosity at that locus. Indel array Agilent-022089 sim-sech.v.1.3
Project description:Curration of small RNAs from four melanogaster-subgroup species (Drosophila simulans, Drosophila sechellia, Drosophila erecta, and Drosophila yakuba) for the purpose of non-coding RNA annotation and comparative genomics assessment.
Project description:Curration of small RNAs from four melanogaster-subgroup species (Drosophila simulans, Drosophila sechellia, Drosophila erecta, and Drosophila yakuba) for the purpose of non-coding RNA annotation and comparative genomics assessment. Non-replicated small RNA samples from four melanogaster-subgroup species.
Project description:Drosophila sechellia relies exclusively on the fruits of Morinda citrifolia, which are toxic to most insects, including its sibling species D. melanogaster and D. simulans. Although several odorant binding protein (Obp) genes and olfactory receptor (Or) genes were suggested to be associated with the D. sechellia host shift, a broad view of how chemosensory genes have contributed to this shift is still lacking. We therefore studied the antennal transcriptomes, the main organ responsible for detecting food resource and oviposition, of D. sechellia and its two sibling species. We wanted to know whether gene expression, particularly chemosensory genes, has diverged between D. sechellia and its two sibling species. Using a very stringent definition of differential gene expression, we found 147 genes (including 11 chemosensory genes) were up-regulated while only 81 genes (including 5 chemosensory genes) were down-regulated in D. sechellia. Interestingly, Obp50a exhibited the highest up-regulation, a ~100 fold increase, and Or85c – previously reported to be a larva-specific gene– showed ~20 fold up-regulation in D. sechellia. Furthermore, Ir84a, proposed to be associated with male courtship behavior, is significantly up-regulated in D. sechellia. We also found expression divergence in most of the receptor gene families between D. sechellia and the two sibling species. Our observations suggest that the host shift of D. sechellia is associated with expression profile divergence in all chemosensory gene families and is achieved mostly by up-regulation of chemosensory genes.
Project description:Drosophila sechellia relies exclusively on the fruits of Morinda citrifolia, which are toxic to most insects, including its sibling species D. melanogaster and D. simulans. Although several odorant binding protein (Obp) genes and olfactory receptor (Or) genes were suggested to be associated with the D. sechellia host shift, a broad view of how chemosensory genes have contributed to this shift is still lacking. We therefore studied the antennal transcriptomes, the main organ responsible for detecting food resource and oviposition, of D. sechellia and its two sibling species. We wanted to know whether gene expression, particularly chemosensory genes, has diverged between D. sechellia and its two sibling species. Using a very stringent definition of differential gene expression, we found 147 genes (including 11 chemosensory genes) were up-regulated while only 81 genes (including 5 chemosensory genes) were down-regulated in D. sechellia. Interestingly, Obp50a exhibited the highest up-regulation, a ~100 fold increase, and Or85c – previously reported to be a larva-specific gene– showed ~20 fold up-regulation in D. sechellia. Furthermore, Ir84a, proposed to be associated with male courtship behavior, is significantly up-regulated in D. sechellia. We also found expression divergence in most of the receptor gene families between D. sechellia and the two sibling species. Our observations suggest that the host shift of D. sechellia is associated with expression profile divergence in all chemosensory gene families and is achieved mostly by up-regulation of chemosensory genes.
Project description:Here we show that Drosophila sechellia—a specialist on the fruit of Morinda citrifolia that recently diverged from its generalist sister-species, D. simulans—has rapidly accumulated loss-of-function alleles and reduced gene expression at genes affecting olfaction, detoxification, and metabolism. While D. sechellia increases expression of genes involved with oogenesis and fatty acid metabolism when on its host, many more genes show reduced expression in D. sechellia. For several functionally related genes, this decrease in expression is associated with loss-of-function alleles. The rapid accumulation of these alleles potentially affected D. sechellia’s initial adaptation to M. citrifolia, likely contributes to D. sechellia’s poor competitive ability off of its host, and increases ecological isolation between D. sechellia and its sister species. Keywords: comparative hybridization, gene expression