Project description:This experiment contains the subset of data corresponding to gray short-tailed opossum RNA-Seq data from experiment E-GEOD-30352 (http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-30352/), which goal is to understand the dynamics of mammalian transcriptome evolution. To study mammalian transcriptome evolution at high resolution, we generated RNA-Seq data (∼3.2 billion Illumina Genome Analyser IIx reads of 76 base pairs) for the polyadenylated RNA fraction of brain (cerebral cortex or whole brain without cerebellum), cerebellum, heart, kidney, liver and testis (usually from one male and one female per somatic tissue and two males for testis) from nine mammalian species: placental mammals (great apes, including humans; rhesus macaque; mouse), marsupials (gray short-tailed opossum) and monotremes (platypus). Corresponding data (∼0.3 billion reads) were generated for a bird (red jungle fowl, a non-domesticated chicken) and used as an evolutionary outgroup.
Project description:Newcastle disease (ND) affects a few hundred avian species including chicken, and the clinical outcome of Newcastle disease virus (NDV) infection ranges from mild to severe fatal disease depending on the NDV pathotype and the host species involved. Japanese quails serve as natural reservoirs of NDV and play important role in NDV epidemiology. While infection of chicken with velogenic NDV results in severe often fatal illness, the same infection in Japanese quails is results in in apparent infection. The molecular basis of this contrasting clinical outcomes of NDV infection is not yet known. We compared global gene expression in spleens of chicken and Japanese quails infected with a lentogenic or velogenic NDVs. We found contrasting regulation of key genes associated with NF-κB pathway and T-cell activation between chicken and Japanese quails. Our data suggests association of NDV resistance in Japanese quails to activation of NF-κB pathway and T cell proliferation.
Project description:Since Japanese quail and chicken belong to the same order Galliforms, DNA sequence of both species are highly conserved and proved to be applicable for various analyses each other. Quail are commonly used to address physiological questions for reasons of economy. To test whether chicken microarrays are useful to quail samples, we compared hybridization signals of chicken and quail genomic DNA on Affymetrix chicken genome array. Keywords: comparative genomic hybridization
Project description:The molecular mechanism of photoperiodic time measurement remains unknown in animals. Japanese quail is an excellent model for studying these phenomena because of their rapid and dramatic response to photoperiod. When quail are transferred from short to long day conditions, increase in plasma gonadotrophin (luteinising hormone: LH) can be observed by the end of the first long day and this phenomenon is called “first day release model”. To dissect the system dynamics and network structure regulating photoperiodism, we examined global gene expression using high-density oligonucleotide microarray for chicken (Affymetrix Chicken Genome Array). Keywords: time course
Project description:The genomes of many vertebrates show a characteristic variation in GC content. To explain its origin and evolution mainly three mechanisms have been proposed, selection for GC content, mutation bias and GC-biased gene conversion. At present the mechanism of GC-biased gene conversion, i.e. short-scale, unidirectional exchanges between homologous chromosomes in the neighborhood of recombination-initiating double-strand breaks in favor for GC nucleotides, is the most widely accepted hypothesis. We here suggest that DNA methylation also plays an important role in the evolution of GC content in vertebrate genomes. To test this hypothesis we investigated one mammalian (human; GSE30340) and one avian (chicken) genome. We used bisulfite sequencing to generate a whole-genome methylation map of chicken sperm. Human processed data files (spermdonor1, #reads>=1) were downloaded from the NGSmethDB database (http://bioinfo2.ugr.es/NGSmethDB/database.php). Inclusion of these methylation maps into a model of GC content evolution provided significant support for the impact of DNA methylation on the local equilibrium GC content. Moreover, two different estimates of equilibrium GC content, one which neglects and one which incorporates the impact of DNA methylation and the concomitant CpG hypermutability, give estimates that differ about 15% in both genomes, arguing for a strong impact of DNA methylation on the evolution of GC content. Thus, our results put forward that previous estimates of equilibrium GC content, which neglect the hypermutability of CpG dinucleotides, need to be reevaluated. Genomic DNA from chicken mature sperm was isolated, bisulfite converted and sequenced on a Illumina HiSeq instrument
Project description:The molecular mechanism of photoperiodic time measurement remains unknown in animals. Japanese quail is an excellent model for studying these phenomena because of their rapid and dramatic response to photoperiod. When quail are transferred from short to long day conditions, increase in plasma gonadotrophin (luteinising hormone: LH) can be observed by the end of the first long day and this phenomenon is called âfirst day release modelâ. To dissect the system dynamics and network structure regulating photoperiodism, we examined global gene expression using high-density oligonucleotide microarray for chicken (Affymetrix Chicken Genome Array). Experiment Overall Design: The mediobasal hypothalamus (MBH) of quail was collected from 6 birds for each time point during the photoinduction process. Pooled total RNA from three MBHs was labelled and hybridized to each Affymetrix chicken genome array. Samples were analyzed in duplicate set of array (two biological replicate).
Project description:Changes in gene expression are thought to underlie many of the phenotypic differences between species. However, large-scale analyses of gene expression evolution were until recently prevented by technological limitations. Here we report the sequencing of polyadenylated RNA from six organs across ten species that represent all major mammalian lineages (placentals, marsupials and monotremes) and birds (the evolutionary outgroup), with the goal of understanding the dynamics of mammalian transcriptome evolution. We show that the rate of gene expression evolution varies among organs, lineages and chromosomes, owing to differences in selective pressures: transcriptome change was slow in nervous tissues and rapid in testes, slower in rodents than in apes and monotremes, and rapid for the X chromosome right after its formation. Although gene expression evolution in mammals was strongly shaped by purifying selection, we identify numerous potentially selectively driven expression switches, which occurred at different rates across lineages and tissues and which probably contributed to the specific organ biology of various mammals. Our transcriptome data provide a valuable resource for functional and evolutionary analyses of mammalian genomes. To study mammalian transcriptome evolution at high resolution, we generated RNA-Seq data (∼3.2 billion Illumina Genome Analyser IIx reads of 76 base pairs) for the polyadenylated RNA fraction of brain (cerebral cortex or whole brain without cerebellum), cerebellum, heart, kidney, liver and testis (usually from one male and one female per somatic tissue and two males for testis) from nine mammalian species: placental mammals (great apes, including humans; rhesus macaque; mouse), marsupials (gray short-tailed opossum) and monotremes (platypus). Corresponding data (∼0.3 billion reads) were generated for a bird (red jungle fowl, a non-domesticated chicken) and used as an evolutionary outgroup.