Project description:Long noncoding RNAs (lncRNAs) are a diverse class of RNAs that are critical for gene regulation, DNA repair and splicing, and have been implicated in cancer, stress response, and development. However, the function of many lncRNAs remains unknown. In Drosophila melanogaster, U snoRNA host gene 4 (Uhg4) encodes an antisense long noncoding RNA that is host to seven small nucleolar RNAs (snoRNAs). Uhg4 is expressed ubiquitously during development and in all adult fly tissues with maximal expression in ovaries; however, it has no annotated function(s). Here, we used CRISPR-Cas9 germline gene editing to generate multiple deletions spanning the promoter region and first exon of Uhg4. Mutant flies were sterile, showed delayed development and decreased viability, and changes in sleep and responses to stress. Whole genome RNA sequencing of Uhg4 deletion flies and their controls identified coregulated genes and genetic interaction networks. Gene ontology analyses highlighted a broad spectrum of biological processes, including morphogenesis, stress response, and regulation of transcription and translation. Thus, Uhg4 is a lncRNA essential for reproduction with pleiotropic effects on multiple fitness traits.
Project description:The abundance of transposable elements and DNA repeat sequences in mammalian genomes raises the question whether such insertions represent passive evolutionary baggage or may influence the expression of complex traits. We addressed this question in Drosophila melanogaster where the effects of single transposable elements on complex traits can be assessed in genetically identical individuals reared in controlled environments. Here we demonstrate that single P-element insertions in the intergenic region between the Gustatory receptor 5a (Gr5a) and Trapped in endoderm 1 (Tre1), which encodes an orphan receptor, exert complex pleiotropic effects on fitness traits, including selective nutrient intake, resistance to starvation and heat stress, and life span. Mutations in this region interact epistatically with downstream components of the insulin signaling pathway. Transposon-induced sex-specific and sex-antagonistic effects further accentuate the complex influences intergenic transposable elements can contribute to complex phenotypes. Keywords: Transcriptional profiles of P-element insertion lines in the Tre1/GR5a region of Drosophila
Project description:The abundance of transposable elements and DNA repeat sequences in mammalian genomes raises the question whether such insertions represent passive evolutionary baggage or may influence the expression of complex traits. We addressed this question in Drosophila melanogaster where the effects of single transposable elements on complex traits can be assessed in genetically identical individuals reared in controlled environments. Here we demonstrate that single P-element insertions in the intergenic region between the Gustatory receptor 5a (Gr5a) and Trapped in endoderm 1 (Tre1), which encodes an orphan receptor, exert complex pleiotropic effects on fitness traits, including selective nutrient intake, resistance to starvation and heat stress, and life span. Mutations in this region interact epistatically with downstream components of the insulin signaling pathway. Transposon-induced sex-specific and sex-antagonistic effects further accentuate the complex influences intergenic transposable elements can contribute to complex phenotypes. SUBMITTER_CITATION: Rollmann SM, Magwire MM, Morgan TJ, Ozsoy ED, Yamamoto A, Mackay TF, Anholt RR. Pleiotropic fitness effects of the Tre1-Gr5a region in Drosophila melanogaster. Nat Genet. 2006 Jul;38(7):824-9. Experiment Overall Design: BG02514, BG02257 and Canton S (B) lines were reared simultaneously at 25 C under a 12 h light/dark cycle and 70% humidity. At 5-7 days post-eclosion, we removed the heads of two replicate groups of 100 males and 100 females for each line. Total RNA was isolated from each replicate and biotinylated cRNA probes were hybridized to high density oligonucleotide microarrays (Affymetrix, Inc.) and visualized with a streptavidin-phycoerythrin conjugate, as described in the Affymetrix GeneChip Expression Analysis Technical Manual (2000), using internal references for quantification. The quantitative estimate of expression of each probe set is the Signal (Sig) metric, as described in the Affymetrix Microarray Suite, Version 5.0. Sig values were analyzed by two-way ANOVA according to the model Y = μ + L + S + LxS + E, where L is the effect of line, S is the effect of sex and E the error variance
Project description:Variation in gene expression arises from cis- and trans-regulatory mutations, which contribute differentially to expression divergence. Here, we compare the impacts on gene expression and fitness for cis- and trans-regulatory mutations affecting expression of the TDH3 gene in Saccharomyces cerevisiae. We use the effects of cis-regulatory mutations to isolate effects of trans-regulatory mutations caused by impacts on TDH3 from pleiotropic impacts on other genes, providing a rare distribution of pleiotropic effects. These pleiotropic effects were often, but not always, deleterious. For cis- and trans-regulatory mutations with similar effects on TDH3, trans-regulatory mutations had more widespread effects on gene expression, with distinct impacts on expression of genes downstream of TDH3. These differences between cis-and trans-regulatory mutations help explain their different contributions to regulatory evolution.
Project description:Differences in the selective pressures experienced by males and females are believed to be ubiquitous in dioecious organisms and are expected to result in the evolution of sexually antagonistic alleles, thereby driving the evolution of sexual dimorphism. Negative genetic correlation for fitness between the sexes has been documented, however, the identity, number and location of loci causing this relationship are unknown. Here we show that a large proportion of Drosophila melanogaster transcripts are associated with the interaction between genomic haplotype and gender and that at least 8% of loci in the fly genome are currently evolving under sexually antagonistic selection. We measured gene expression of adult males and females of Drosophila melanogaster from 15 hemiclone lines, showing either high-male/low-female fitness, high-female/lowmale fitness or average fitness in both sexes. Data from four replicates for each sex/line are presented, giving a total of 120 arrays.
Project description:Royal Jelly (RJ) is a product made by honey bee workers and is required for queen differentiation and accompanying changes in queen body size, development time, lifespan and reproductive output relative to workers. Previous studies have reported similar changes in Drosophila melanogaster in response to RJ. Here, we quantified viability, development time, body size, productivity, lifespan and genome wide transcript abundance of D. melanogaster reared on standard culture medium supplemented with increasing concentrations of RJ. We found that lower concentrations of RJ do induce significant differences in body size in both sexes; higher concentrations reduce size, increase mortality, shorten lifespan and reduce productivity. Increased concentrations of RJ also consistently lengthened development time in both sexes. RJ is associated with changes in expression of 1,581 probe sets assessed using Affymetrix Drosophila 2.0 microarrays, which were enriched for genes associated with metabolism and amino acid degradation. The transcriptional changes are consistent with alterations in cellular processes to cope with excess nutrients provided by RJ, including biosynthesis and detoxification, which might contribute to accelerated senescence and reduced lifespan.
Project description:Intralocus sexual conflict, where males and females have different fitness optima for the same trait, has been suggested to potentially be resolved by genomic imprinting, whereby expression in offspring is altered according to parent-of-origin. However, this idea has not yet been empirically tested. Here, we designed an experimental evolution protocol in Drosophila melanogaster which enabled us to look for imprinting effects on the X-chromosome. We enforced father-to-son transmission of the X-chromosome for many generations, and compared fitness and gene expression levels between control males, males with a control X-chromosome that had undergone one generation of father-son transmission (CDX), and males with an X-chromosome that had undergone many generations of father-son transmission (MLX). Although fitness differences were consistent with lowered fitness of males with a paternally inherited X-chromosome, expression differences suggested that this was due to deleterious maternal effects rather than imprinting. We conclude that imprinting is unlikely to resolve intralocus sexual conflict in Drosophila melanogaster.
Project description:Thermal acclimation study on Drosophila melanogaster reared at 3 different temperatures (12, 25, and 31oC). The proteomic profiles of D. melanogaster under these different temperatures were analyzed and compared using label-free tandem mass spectrometry.