Project description:a robust comparative genomic hybridization (CGH) approach was used with three strains of different Thiomonas species and five different strains of the same species.
Project description:Peanut (Arachis hypogaea) has a large (~2.7 Gbp) allotetraploid genome with closely related component genomes making its genome very challenging to assemble. Here we report genome sequences of its diploid ancestors (A. duranensis and A. ipaënsis). We show they are similar to the peanutâs A- and B-genomes and use them use them to identify candidate disease resistance genes, create improved tetraploid transcript assemblies, and show genetic exchange between peanutâs component genomes. Based on remarkably high DNA identity and biogeography, we conclude that A. ipaënsis may be a descendant of the very same population that contributed the B-genome to cultivated peanut. Whole Genome Bisulphite Sequencing of the peanut species Arachis duranensis and Arachis ipaensis.
Project description:Haemophilus influenzae(Hi) is a gram-negative rod shaped bacterium that lives symbiotically in the upper respiratory tract of humans. Capsulated Hi, as well as non-capsulated strains are known to cause a number of significant infections. Recognizing and understanding the links between the phenotypic traits and the genetic background has paramount epidemiological and clinical importance. To date, a panoply of microbiological and molecular biology tools have been developed and utilized by researchers aimed at identifying the evolutionary links among strains and isolates. Comparative genomic hybridization (CGH) has been shown to be a useful tool for screening strains for their genetic content. However, there is a major limitation when CGH is conducted on a microarray based on a single reference genome. CGH results report which genes are present or absent relative to the genome. Hence the information about novel genetic content that the query strain possesses remains obscure. We report here the construction of the first Hi pan-genome microarray representing ca. 4600 features by 70-mers. In addition to those from the Rd strain, new features originate from the unfinished genome sequences present in NCBI database and from our novel gene discovery project efforts using strain HK1212. Genomes of 20strains belonging to different phylogenetic lineages were screened for their gene loss and gain utilizing the species microarray. The results obtained by employing the multistrain species microarray provide comprehensive information about the genomic content of uncharacterized strains. The trees generated by CGH, in general, do not reproduce the phylogeny of a species in terms of vertical evolution, but instead represents the overall relatedness of genomes to one another and provide an assessment about the species genome evolution. Keywords: Comparative Genomic Hybridization
Project description:Extensive sex-biased expression has been seen in multiple surveys D. melanogaster. We were interested in broadly sampling sex-biased expression of orthologs and species- or lineage-specific genes in the Drosophila genus. To appropriately assay gene expression in multiple species, we used custom microarrays designed against each of six species that broadly sample the phylogenetic space represented by the newly completed genomes (D. simulans, D. yakuba, D. ananassae, D. pseudoobscura, D. virilis and D. mojavensis) and an array designed against D. melanogaster to determine the overall patterns of sex-biased expression in those species and their chromosome linkage. Keywords: other PolyA+ mRNA in duplicate were isolated from 5-7 day old adult females and males of seven drosophila species. Male and female mRNA was labeled by Cy3 or Cy5 dye separately and hybridized simultaneously to the appropriate species-specific arrays. We performed at least four two-channel hybridizations for each species including two biological replicates and dye-swaps for each of them. Only single channels which passed stringent pre-processing quality control were used. A total of 67 channels of data were used in the final analysis.
Project description:Extensive sex-biased expression has been seen in multiple surveys D. melanogaster. We were interested in broadly sampling sex-biased expression of orthologs and species- or lineage-specific genes in the Drosophila genus. To appropriately assay gene expression in multiple species, we used custom microarrays designed against each of six species that broadly sample the phylogenetic space represented by the newly completed genomes (D. simulans, D. yakuba, D. ananassae, D. pseudoobscura, D. virilis and D. mojavensis) and an array designed against D. melanogaster to determine the overall patterns of sex-biased expression in those species and their chromosome linkage. Keywords: other
Project description:Background: Array comparative genomic hybridization (aCGH) is commonly used to screen different types of genetic variation in humans and model species. Here, we performed aCGH using an oligonucleotide gene-expression array for a non-model species, the intertidal snail Littorina saxatilis. First, we tested what types of genetic variation can be detected by this method using direct re-sequencing and comparison to the Littorina genome draft. Secondly, we performed a genome-wide comparison of four closely related Littorina species: L. fabalis, L. compressa, L. arcana and L. saxatilis and of populations of L. saxatilis found in Spain, Britain and Sweden. Finally, we tested whether we could identify genetic variation underlying “Crab” and “Wave” ecotypes of L. saxatilis. Results: We could reliably detect copy number variations, deletions and high sequence divergence (i.e. above 3%), but not single nucleotide polymorphisms. The overall hybridization pattern and number of significantly diverged genes were in close agreement with earlier phylogenetic reconstructions based on single genes. The trichotomy of L. arcana, L. compressa and L. saxatilis could not be resolved and we argue that these divergence events have occurred recently and very close in time. We found evidence for high levels of segmental duplication in the Littorina genome (10% of the transcripts represented on the array and up to 23% of the analyzed genomic fragments); duplicated genes and regions were mostly the same in all analyzed species. Finally, this method discriminated geographically distant populations of L. saxatilis, but we did not detect any significant genome divergence associated with ecotypes of L. saxatilis. Conclusions: The present study provides new information on the sensitivity and the potential use of oligonucleotide arrays for genotyping of non-model organisms. Applying this method to Littorina species yields insights into genome evolution following the recent species radiation and supports earlier single-gene based phylogenies. Genetic differentiation of L. saxatilis ecotypes was not detected in this study, despite pronounced innate phenotypic differences. The reason may be that these differences are due to single-nucleotide polymorphisms.
2014-07-29 | GSE59825 | GEO
Project description:Population genomic and phylogenetic analysis of three wireworm (Coleoptera: Elateridae) species
Project description:28 Streptomyces strains isolated from common scab lesions of potato tubers from a wide geographic range in Norway, were selected for microarray analysis. The selected strains were subjected to species identification by microarray, 16S phylogenetic analysis and PCR; and microarray-based comparative genome analysis. To our knowledge, this is the first report of S. turgidiscabies and S. europaeiscabiei in Norway.
Project description:Strain SM1988T is a Gram-negative, aerobic, oxidase- and catalase-positive, unipolar flagellated, and rod-shaped bacterium capable of hydrolyzing casein, gelatin and collagens. Phylogenetic analysis revealed that strain SM1988T formed a distinct phylogenetic lineage along with known genera within the family Pseudoalteromonadaceae, with 16S rRNA gene sequence similarity being less than 93.3% to all known species in the family. Based on the phylogenetic, genomic, chemotaxonomic and phenotypic data, strain SM1988T was considered to represent a novel species in a novel genus in the family Pseudoalteromonadaceae, for which the name Flocculibacter collagenilyticus gen. nov., sp. nov. is proposed, with the type strain being SM1988T (= MCCC 1K04279T = KCTC 72761T). Strain SM1988T showed a high production (236 U/mL) of extracellular collagenases, which had high activity against both bovine collagen and codfish collagen. Biochemical tests combined with genomic and secretomic analyses indicated that the collagenases secreted by strain SM1988T are serine proteases from the S8 family. These data suggest that strain SM1988T acts as an important player in marine collagen degradation and recycling and may have a promising potential in collagen resource utilization.