No accelerated rate of protein evolution in male biased Drosophila pseudoobscura genes
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ABSTRACT:
ORGANISM(S): Drosophila pseudoobscura
PROVIDER: GSE2840 | GEO | 2006/07/27
SECONDARY ACCESSION(S): PRJNA92475
REPOSITORIES: GEO
Similar Datasets
Project description:Sexually dimorphic traits are subject to diversifying selection. Also genes with a male biased gene expression are probably affected by sexual selection and have a high rate of protein evolution. We used SAGE to measure sex biased gene expression in Drosophila pseudoobscura. Consistent with previous results from D. melanogaster, a larger number of genes were male biased (402 genes) than female biased (138 genes). About 34% of the genes changed the sex related expression pattern between D. melanogaster and D. pseudoobscura. Combining gene expression with protein divergence between both species, we observed a striking difference in rate of evolution for genes with a male biased gene expression in one species only. Contrary to expectations, D. pseudoobscura genes in this category showed no accelerated rate of protein evolution, while D. melanogaster genes did. If sexual selection is driving molecular evolution of male biased genes, our data imply a radically different selection regime in D. pseudoobscura. Keywords: SAGE Male and female SAGE libraries of D. pseudoobscura were developed for analyzing the gene expression pattern.
2006-07-27 | E-GEOD-2840 | biostudies-arrayexpress
Project description:No accelerated rate of protein evolution in male biased Drosophila pseudoobscura genes
| PRJNA92475 | ENA
Project description:Recent studies have revealed key roles of non-coding RNAs in sex-related pathways, but little is known about the evolutionary forces acting on these non-coding RNAs. We used whole-genome tiling arrays to profile the transcriptome of Drosophila melanogaster tissues and found that 15% of male-biased transcribed fragments (transfrags) are intergenic non-coding RNAs (incRNAs), suggesting a potentially important role for incRNAs in sex-related biological processes. Statistical analysis revealed a paucity of male-biased incRNAs and coding genes on the X chromosome, suggesting that similar evolutionary forces could be affecting the genomic organization of both coding and non-coding genes. Expression profiling across germline and somatic tissues further suggests that both male meiotic sex chromosome inactivation (MSCI) and sexual antagonism contribute to the chromosomal distribution of male-biased incRNAs. Comparative sequence analysis shows that the evolutionary age of male-biased incRNAs is a significant predictor of their chromosomal locations. In addition to identifying abundant sex-biased incRNAs in fly genome, our work unveils a global picture of the complex interplay between non-coding RNAs and sexual chromosome evolution. We used whole-genome tiling arrays to assess sex-biased transcription in D. melanogaster adult whole bodies, and testis, ovary, and accessory gland samples. Gut and thorax, tissues expected to exhibit little or no sex-biased expression, were included as controls. Expression was measured in 2-4 replicates for each tissue.
2013-12-18 | E-GEOD-53421 | biostudies-arrayexpress
Project description:Recent studies have revealed key roles of non-coding RNAs in sex-related pathways, but little is known about the evolutionary forces acting on these non-coding RNAs. We used whole-genome tiling arrays to profile the transcriptome of Drosophila melanogaster tissues and found that 15% of male-biased transcribed fragments (transfrags) are intergenic non-coding RNAs (incRNAs), suggesting a potentially important role for incRNAs in sex-related biological processes. Statistical analysis revealed a paucity of male-biased incRNAs and coding genes on the X chromosome, suggesting that similar evolutionary forces could be affecting the genomic organization of both coding and non-coding genes. Expression profiling across germline and somatic tissues further suggests that both male meiotic sex chromosome inactivation (MSCI) and sexual antagonism contribute to the chromosomal distribution of male-biased incRNAs. Comparative sequence analysis shows that the evolutionary age of male-biased incRNAs is a significant predictor of their chromosomal locations. In addition to identifying abundant sex-biased incRNAs in fly genome, our work unveils a global picture of the complex interplay between non-coding RNAs and sexual chromosome evolution.
2013-12-18 | GSE53421 | GEO
Project description:A number of genes associated with sexual traits and reproduction evolve at the sequence level faster than the majority of genes coding for non-sex-related traits. Whole genome analyses allow this observation to be extended beyond the limited set of genes that have been studied thus far. We use cDNA microarrays to demonstrate that this pattern holds in Drosophila for the phenotype of gene expression as well, but in one sex only. Genes that are male-biased in their expression show more variation in relative expression levels between conspecific populations and two closely related species than do female-biased genes or genes with sexually monomorphic expression patterns. Additionally, elevated ratios of interspecific expression divergence to intraspecific expression variation among male-biased genes suggest that differences in rates of evolution may be due in part to natural selection. This finding has implications for our understanding of the importance of sexual dimorphism for speciation and rates of phenotypic evolution. Keywords: other
2003-07-19 | GSE539 | GEO
Project description:Early embryogenesis is a unique developmental stage where genetic control of development is handed off from mother to zygote. Yet the contribution of this transition to the evolution of gene expression is poorly understood. Here we study two aspects of gene expression specific to early embryogenesis in Drosophila: sex-biased gene expression prior to the onset of canonical X chromosomal dosage compensation, and the contribution of maternally supplied mRNAs. We sequenced mRNAs from individual unfertilized eggs, precisely staged and sexed blastoderm embryos and compared levels between D. melanogaster, D. yakuba, D. pseudoobscura and D. virilis. First, we find that mRNA content is highly conserved for a given stage and that studies relying on pooled embryos may systematically overstate the degree of gene expression divergence. Unlike studies done on larvae and adults, where most species show a larger proportion of genes with male-biased expression, we find that transcripts in Drosophila embryos are largely female-biased in all species, likely due to incomplete dosage compensation prior to the activation of the canonical dosage compensation mechanism. The divergence of sex-biased gene expression across species is observed to be often due to a decrease of expression, the most drastic example of which is the overall reduction of male expression from the neo-X chromosome in D. pseudoobscura, leading to a pervasive female-bias on this chromosome. We see no evidence for a faster evolution of expression on the X chromosome in embryos (no “faster X” effect), unlike in adults and contrary to a previous study on pooled non-sexed embryos. Finally, we find that most genes are conserved in regard to their maternal or zygotic origin of transcription, and present evidence that differences in maternal contribution to the blastoderm transcript pool may be due to species-specific divergence of transcript degradation rates We sequenced mRNA from D. melanogaser, D. yakuba, D. pseudoobscura and D. virilis single unfertilized eggs (1 to 2 per species) and from both single female and male embryos (3 per sex per species).
2015-04-21 | E-GEOD-68062 | biostudies-arrayexpress
Project description:Genes with sex-biased expression often show rapid molecular evolution between species. Previous population genetic and comparative genomic studies of Drosophila melanogaster and D. simulans revealed that male-biased genes have especially high rates of adaptive evolution. To test if this is also the case for other lineages within the melanogaster group, we investigated gene expression in D. ananassae, a species that occurs in structured populations in tropical and subtropical regions. We used custom-made microarrays and published microarray data to characterize the sex-biased expression of 129 D. ananassae genes whose D. melanogaster orthologs had been classified previously as male-biased, female-biased, or unbiased in their expression and had been studied extensively at the population-genetic level.
2009-11-21 | GSE19096 | GEO
Project description:Background: Stalk-eyed flies (family Diopsidae) are a model system for studying sexual selection due to the presence of elongated and sexually dimorphic eye-stalks in many species. Recent genomic studies on these flies have revealed a neo-X chromosome and evidence of gene movement onto or off of this X chromosome. To determine if sex linkage and gene movement are related to sexual dimorphism and sexual conflict, we compared gene expression between males and females using oligonucleotide microarrays and RNA from either developing eyestalk tissue or adult heads from a dimorphic species, Teleopsis dalmanni, or from developing eyestalk tissue in a congeneric monomorphic species, T. quinqueguttata. Results: Comparison of gene expression between the sexes for 3,748 genes indicates that dosage compensation is present due to elevated expression of X-linked genes in males. However, sex-biased expression was detected in 26% of the genes present in eye-antennal imaginal discs of larval T. dalmanni. Functional annotation reveals that female-biased genes are associated with transcription, anatomical development and cell communication in the nucleus, while male-biased genes are associated with metabolism and the mitochondria. Comparison of gene expression between experiments identified 140 genes with concordant sex-biased expression in the larval and adult tissues of T. dalmanni and 17 genes with identical sex-biased expression between species. There were only five reversals of sex-biased expression across experiments. In T. dalmanni, male-biased genes are more common on autosomes than on the X while female-biased genes are more common on the X in T. quinqueguttata. Female-biased expression is especially common among genes that moved onto the ancestral X while male-biased expression is more common among genes that moved onto an autosome. Conclusions: Genes with sex-biased expression exhibit different functions in each sex as expected if sexual conflict has influenced their evolution. The strong relationship between sex-biased expression and gene movement found in this study is consistent with resolution of sexual conflict by an RNA- or DNA-mediated process that moves genes between chromosomes. Measurement of gene expression in additional species should provide a more complete picture of how gene expression change occurs over evolutionary time in these extraordinary flies. Two-condition experiment, female vs. male RNA using larval eye discs for two species (Teleopsis dalmanni, Teleopsis quinqueguttata), and adult heads for one species (Teleopsis dalmanni).
2012-04-09 | E-GEOD-37121 | biostudies-arrayexpress
Project description:The extraordinary range in the degree of sexual dimorphism (SD) among animal species is widely perceived to be caused in part by differences in patterns of sexual selection, but sex-specific adaptations and sex chromosome differences also play a role. Studies in insects have discovered a substantial number of sex-biased genes, but little is known about the epigenetic basis of SD. The degree and genome-wide distribution of sex-biased expression become interesting questions in hymenoptera species with haplodiploid sex-determination. To study the genetic and epigenetic architecture of SD and understand the conservation and evolution of sex-biased expression in a haplodiploid system that lacks sex chromosomes, we performed RNA-seq and whole-genome bisulfite sequencing in female and male adult samples of two parasitoid wasp species, Nasonia vitripennis and Nasonia giraulti. More than 75% of the expressed genes displayed significantly sex-biased expression. Both the number and the degree of sex-biased genes are higher than insects like Drosophila melanogaster, which have sex-chromosome mediated sex determination. Females from the two Nasonia species have far more similar expression profiles than does the contrast between the two sexes within either species. Interestingly, the extremely male- and female-biased genes are enriched for totally different functional categories: male-biased genes are highly enriched for key enzymes in sex-pheromone synthesis; female-biased genes are enriched for nuclear-located genes that are responsible for epigenetic regulation of gene expression. Unlike gene expression profiles, DNA methylomes are more similar within species, and no stable differentially methylated genes have been found between the two sexes, suggesting that DNA methylation is not directly responsible for the molecular basis of SD. However, methylation status does influence sex-biased expression: 80% of female-biased genes are methylated, which is more than two-fold higher than the genome average (30%); almost all male-biased and sex-specific genes are non-methylated, which is consistent with the fact that methylated genes have house-keeping functions and a broader expression breadth. Evolutionarily, male-biased genes have greater sequence divergence between the two species, and they are more likely to have a functional paralog in the Nasonia genome. Sex-specific genes have significantly higher non-synonymous substitution rates and dN/dS ratios. In addition, local clusters of sex-biased genes in the genome may have epigenetic properties similar to the sex chromosome. In summary, Nasonia accomplish a striking degree of sex-differential expression through a difference in ploidy along with associated differences in methylations status. Profiling of expression levels in Nasonia vitripennis and Nasonia giraulti adult male and female samples using Illumina RNA-seq
2015-06-08 | E-GEOD-61156 | biostudies-arrayexpress
Project description:Although not all sex-dependent gene expression is adaptive, it is likely an important genomic mechanism that allows each sex to independently adapt to environmental changes. Among Drosophila species, sex-biased genes display remarkably consistent evolutionary patterns; male-biased genes evolve faster than unbiased genes in both coding sequence and expression level, suggesting sex-differences in selection through time. However, comparatively little is known of the evolutionary process shaping sex-biased expression within species. Latitudinal clines offer an opportunity to examine how changes in key ecological parameters also influence sex-specific selection and the evolution of sex-biased gene expression. We assayed male and female gene expression in Drosophila serrata along a latitudinal gradient in eastern Australia spanning most of its endemic distribution. Analysis of 11,631 genes across eight populations revealed strong sex differences in the frequency, mode, and strength of divergence. Divergence was far stronger in males than females and while latitudinal clines were evident in both sexes, male divergence was often population-specific, suggesting responses to localized selection pressures that do not covary predictably with latitude. While divergence was enriched for male-biased genes, there was no overrepresentation of X-linked genes in males. By contrast, X-linked divergence was elevated in females, especially for female biased genes. Many genes that diverged in D. serrata have homologs also showing latitudinal divergence in D. simulans and D. melanogaster on other continents, likely indicating parallel adaptation in these distantly related species. Our results suggest that sex differences in selection play an important role in shaping the evolution of gene expression over macro- and micro-ecological spatial scales.
2017-01-04 | GSE90733 | GEO