@article {38583, title = {Enhancer networks revealed by correlated DNAse hypersensitivity states of enhancers}, journal = {Nucleic Acids ResNucleic Acids ResNucleic Acids Res}, volume = {41}, number = {14}, year = {2013}, note = {Malin, Justin
Aniba, Mohamed Radhouane
Hannenhalli, Sridhar
eng
R01 GM100335/GM/NIGMS NIH HHS/
R01GM100335/GM/NIGMS NIH HHS/
Research Support, N.I.H., Extramural
England
2013/05/24 06:00
Nucleic Acids Res. 2013 Aug;41(14):6828-38. doi: 10.1093/nar/gkt374. Epub 2013 May 21.}, month = {Aug}, pages = {6828-38}, abstract = {Mammalian gene expression is often regulated by distal enhancers. However, little is known about higher order functional organization of enhancers. Using approximately 100 K P300-bound regions as candidate enhancers, we investigated their correlated activity across 72 cell types based on DNAse hypersensitivity. We found widespread correlated activity between enhancers, which decreases with increasing inter-enhancer genomic distance. We found that correlated enhancers tend to share common transcription factor (TF) binding motifs, and several chromatin modification enzymes preferentially interact with these TFs. Presence of shared motifs in enhancer pairs can predict correlated activity with 73\% accuracy. Also, genes near correlated enhancers exhibit correlated expression and share common function. Correlated enhancers tend to be spatially proximal. Interestingly, weak enhancers tend to correlate with significantly greater numbers of other enhancers relative to strong enhancers. Furthermore, strong/weak enhancers preferentially correlate with strong/weak enhancers, respectively. We constructed enhancer networks based on shared motif and correlated activity and show significant functional enrichment in their putative target gene clusters. Overall, our analyses show extensive correlated activity among enhancers and reveal clusters of enhancers whose activities are coordinately regulated by multiple potential mechanisms involving shared TF binding, chromatin modifying enzymes and 3D chromatin structure, which ultimately co-regulate functionally linked genes.}, keywords = {*Deoxyribonucleases, *Enhancer Elements, Genetic, Chromatin/chemistry, Gene expression, Gene Regulatory Networks, HUMANS, Transcription Factors/metabolism}, isbn = {1362-4962 (Electronic)
0305-1048 (Linking)}, author = {Malin, J. and Aniba, M. R. and Sridhar Hannenhalli} } @article {38421, title = {The partitioned LASSO-patternsearch algorithm with application to gene expression data}, journal = {BMC bioinformaticsBMC Bioinformatics}, volume = {13}, year = {2012}, note = {http://www.ncbi.nlm.nih.gov/pubmed/22587526?dopt=Abstract}, type = {10.1186/1471-2105-13-98}, abstract = {BACKGROUND: In systems biology, the task of reverse engineering gene pathways from data has been limited not just by the curse of dimensionality (the interaction space is huge) but also by systematic error in the data. The gene expression barcode reduces spurious association driven by batch effects and probe effects. The binary nature of the resulting expression calls lends itself perfectly to modern regularization approaches that thrive in high-dimensional settings. RESULTS: The Partitioned LASSO-Patternsearch algorithm is proposed to identify patterns of multiple dichotomous risk factors for outcomes of interest in genomic studies. A partitioning scheme is used to identify promising patterns by solving many LASSO-Patternsearch subproblems in parallel. All variables that survive this stage proceed to an aggregation stage where the most significant patterns are identified by solving a reduced LASSO-Patternsearch problem in just these variables. This approach was applied to genetic data sets with expression levels dichotomized by gene expression bar code. Most of the genes and second-order interactions thus selected and are known to be related to the outcomes. CONCLUSIONS: We demonstrate with simulations and data analyses that the proposed method not only selects variables and patterns more accurately, but also provides smaller models with better prediction accuracy, in comparison to several alternative methodologies.}, keywords = {algorithms, Breast Neoplasms, Computer simulation, Female, Gene expression, Gene Expression Profiling, Genomics, HUMANS, Models, Genetic}, author = {Shi, Weiliang and Wahba, Grace and Irizarry, Rafael A. and H{\'e}ctor Corrada Bravo and Wright, Stephen J.} } @article {38472, title = {Role of transposable elements in trypanosomatids}, journal = {Microbes and InfectionMicrobes and Infection}, volume = {10}, year = {2008}, type = {16/j.micinf.2008.02.009}, abstract = {Transposable elements constitute 2-5\% of the genome content in trypanosomatid parasites. Some of them are involved in critical cellular functions, such as the regulation of gene expression in Leishmania spp. In this review, we highlight the remarkable role extinct transposable elements can play as the source of potential new functions.}, keywords = {Cellular function, Domestication, Evolution, Gene expression, Leishmania, Regulation of mRNA stability, Retroposon, Transposable element, Trypanosoma}, isbn = {1286-4579}, author = {Bringaud, Frederic and Ghedin, Elodie and Najib M. El-Sayed and Papadopoulou, Barbara} } @article {49643, title = {Schistosoma mansoni: Microarray analysis of gene expression induced by host sex.}, journal = {Exp Parasitol}, volume = {120}, year = {2008}, month = {2008 Dec}, pages = {357-63}, abstract = {

Schistosoma mansoni is a digenetic trematode and a human parasite responsible for high social and economic impact. Although some authors have studied the effect of host hormones on parasites, not much is known about the effects of host sex on gene expression in Schistosomes. In order to study gene transcripts associated with the host sex, we compared the gene expression profiles of both male and female unisexual adult S. mansoni parasites raised on either male or female hosts, using DNA microarrays. Our results show that host sex caused differential expression of at least 11 genes in female parasites and of 134 in male parasites. Of the differentially expressed genes in female worms, 10 were preferentially expressed in female worms from male mice, while of the 134 differentially expressed genes in male parasites, 79 (59\%) were preferentially expressed in worms from female mice. Further investigation of the role of each of those genes will help understand better their importance in the pathogenesis of Schistosomiasis.

}, keywords = {Animals, Biomphalaria, Female, Gene expression, Host-Parasite Interactions, Male, Mice, Oligonucleotide Array Sequence Analysis, Reverse Transcriptase Polymerase Chain Reaction, RNA, Helminth, Schistosoma mansoni, Schistosomiasis mansoni, Sex Factors}, issn = {1090-2449}, doi = {10.1016/j.exppara.2008.09.005}, author = {Waisberg, M and Lobo, F P and Cerqueira, G C and Passos, L K J and Carvalho, O S and El-Sayed, N M and Franco, G R} } @article {38287, title = {Genome analysis of multiple pathogenic isolates of Streptococcus agalactiae: implications for the microbial "pan-genome"}, journal = {Proceedings of the National Academy of Sciences of the United States of AmericaProceedings of the National Academy of Sciences of the United States of America}, volume = {102}, year = {2005}, note = {http://www.ncbi.nlm.nih.gov/pubmed/16172379?dopt=Abstract}, type = {10.1073/pnas.0506758102}, abstract = {The development of efficient and inexpensive genome sequencing methods has revolutionized the study of human bacterial pathogens and improved vaccine design. Unfortunately, the sequence of a single genome does not reflect how genetic variability drives pathogenesis within a bacterial species and also limits genome-wide screens for vaccine candidates or for antimicrobial targets. We have generated the genomic sequence of six strains representing the five major disease-causing serotypes of Streptococcus agalactiae, the main cause of neonatal infection in humans. Analysis of these genomes and those available in databases showed that the S. agalactiae species can be described by a pan-genome consisting of a core genome shared by all isolates, accounting for approximately 80\% of any single genome, plus a dispensable genome consisting of partially shared and strain-specific genes. Mathematical extrapolation of the data suggests that the gene reservoir available for inclusion in the S. agalactiae pan-genome is vast and that unique genes will continue to be identified even after sequencing hundreds of genomes.}, keywords = {Amino Acid Sequence, Bacterial Capsules, Base Sequence, Gene expression, Genes, Bacterial, Genetic Variation, Genome, Bacterial, Molecular Sequence Data, Phylogeny, sequence alignment, Sequence Analysis, DNA, Streptococcus agalactiae, virulence}, author = {Tettelin, Herv{\'e} and Masignani, Vega and Cieslewicz, Michael J. and Donati, Claudio and Medini, Duccio and Ward, Naomi L. and Angiuoli, Samuel V. and Crabtree, Jonathan and Jones, Amanda L. and Durkin, A. Scott and DeBoy, Robert T. and Davidsen, Tanja M. and Mora, Marirosa and Scarselli, Maria and Margarit y Ros, Immaculada and Peterson, Jeremy D. and Hauser, Christopher R. and Sundaram, Jaideep P. and Nelson, William C. and Madupu, Ramana and Brinkac, Lauren M. and Dodson, Robert J. and Rosovitz, Mary J. and Sullivan, Steven A. and Daugherty, Sean C. and Haft, Daniel H. and J. Selengut and Gwinn, Michelle L. and Zhou, Liwei and Zafar, Nikhat and Khouri, Hoda and Radune, Diana and Dimitrov, George and Watkins, Kisha and O{\textquoteright}Connor, Kevin J. B. and Smith, Shannon and Utterback, Teresa R. and White, Owen and Rubens, Craig E. and Grandi, Guido and Madoff, Lawrence C. and Kasper, Dennis L. and Telford, John L. and Wessels, Michael R. and Rappuoli, Rino and Fraser, Claire M.} } @proceedings {38218, title = {Dynamic querying for pattern identification in microarray and genomic data}, volume = {3}, year = {2003}, month = {2003}, publisher = {IEEE}, type = {10.1109/ICME.2003.1221346}, abstract = {Data sets involving linear ordered sequences are a recurring theme in bioinformatics. Dynamic query tools that support exploration of these data sets can be useful for identifying patterns of interest. This paper describes the use of one such tool - timesearcher - to interactively explore linear sequence data sets taken from two bioinformatics problems. Microarray time course data sets involve expression levels for large numbers of genes over multiple time points. Timesearcher can be used to interactively search these data sets for genes with expression profiles of interest. The occurrence frequencies of short sequences of DNA in aligned exons can be used to identify sequences that play a role in the pre-mRNA splicing. Timesearcher can be used to search these data sets for candidate splicing signals.}, keywords = {Bioinformatics, data sets, Displays, dynamic querying, expression profiles, Frequency, Gene expression, genes, Genetics, genomic data, Genomics, linear ordered sequences, macromolecules, medical signal processing, Mice, Microarray, pattern identification, pattern recognition, premRNA splicing, Query processing, sequences, Signal processing, splicing, TimeSearcher}, isbn = {0-7803-7965-9}, author = {Hochheiser, H. and Baehrecke, E. H. and Stephen M. Mount and Shneiderman, Ben} } @article {49629, title = {Analysis of stage-specific gene expression in the bloodstream and the procyclic form of Trypanosoma brucei using a genomic DNA-microarray.}, journal = {Mol Biochem Parasitol}, volume = {123}, year = {2002}, month = {2002 Aug 28}, pages = {115-23}, abstract = {

A microarray comprising 21,024 different PCR products spotted on glass slides was constructed for gene expression studies on Trypanosoma brucei. The arrayed fragments were generated from a T. brucei shotgun clone library, which had been prepared from randomly sheared and size-fractionated genomic DNA. For the identification of stage-specific gene activity, total RNA from in vitro cultures of the human, long slender form and the insect, procyclic form of the parasite was labelled and hybridised to the microarray. Approximately 75\% of the genomic fragments produced a signal and about 2\% exhibited significant differences between the transcript levels in the bloodstream and procyclic forms. A few results were confirmed by Northern blot analysis or reverse-transcription and PCR. Three hundred differentially regulated clones have been selected for sequencing. So far, of 33 clones that showed about 2-fold or more over-expression in bloodstream forms, 15 contained sequences similar to those of VSG expression sites and at least six others appeared non-protein-coding. Of 29 procyclic-specific clones, at least eight appeared not to be protein-coding. A surprisingly large proportion of known regulated genes was already identified in this small sample, and some new ones were found, illustrating the utility of genomic arrays.

}, keywords = {Animals, Blotting, Northern, Escherichia coli, Gene expression, Gene Expression Profiling, Genes, Protozoan, HUMANS, Life Cycle Stages, Molecular Sequence Data, Oligonucleotide Array Sequence Analysis, Polymerase Chain Reaction, Transcription, Genetic, Trypanosoma brucei brucei}, issn = {0166-6851}, author = {Diehl, Susanne and Diehl, Frank and El-Sayed, Najib M and Clayton, Christine and Hoheisel, J{\"o}rg D} } @article {49706, title = {Structure and expression of the Drosophila melanogaster gene for the U1 small nuclear ribonucleoprotein particle 70K protein.}, journal = {Mol Cell Biol}, volume = {10}, year = {1990}, month = {1990 Jun}, pages = {2492-502}, abstract = {

A genomic clone encoding the Drosophila U1 small nuclear ribonucleoprotein particle 70K protein was isolated by hybridization with a human U1 small nuclear ribonucleoprotein particle 70K protein cDNA. Southern blot and in situ hybridizations showed that this U1 70K gene is unique in the Drosophila genome, residing at cytological position 27D1,2. Polyadenylated transcripts of 1.9 and 3.1 kilobases were observed. While the 1.9-kilobase mRNA is always more abundant, the ratio of these two transcripts is developmentally regulated. Analysis of cDNA and genomic sequences indicated that these two RNAs encode an identical protein with a predicted molecular weight of 52,879. Comparison of the U1 70K proteins predicted from Drosophila, human, and Xenopus cDNAs revealed 68\% amino acid identity in the most amino-terminal 214 amino acids, which include a sequence motif common to many proteins which bind RNA. The carboxy-terminal half is less well conserved but is highly charged and contains distinctive arginine-rich regions in all three species. These arginine-rich regions contain stretches of arginine-serine dipeptides like those found in transformer, transformer-2, and suppressor-of-white-apricot proteins, all of which have been identified as regulators of mRNA splicing in Drosophila melanogaster.

}, keywords = {Amino Acid Sequence, Animals, Base Sequence, Blotting, Northern, Blotting, Southern, Cloning, Molecular, DNA, Drosophila melanogaster, Gene expression, Gene Library, genes, HUMANS, Molecular Sequence Data, Molecular Weight, Oligonucleotide Probes, Poly A, Ribonucleoproteins, Ribonucleoproteins, Small Nuclear, RNA, RNA, Messenger, Sequence Homology, Nucleic Acid, Xenopus}, issn = {0270-7306}, author = {Mancebo, R and Lo, P C and Mount, S M} }