Genome-wide identification of coding and non-coding conserved sequence tags in human and mouse genomes

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Maggi Giorgio P

2008-06-01

Full Text Available Abstract Background The accurate detection of genes and the identification of functional regions is still an open issue in the annotation of genomic sequences. This problem affects new genomes but also those of very well studied organisms such as human and mouse where, despite the great efforts, the inventory of genes and regulatory regions is far from complete. Comparative genomics is an effective approach to address this problem. Unfortunately it is limited by the computational requirements needed to perform genome-wide comparisons and by the problem of discriminating between conserved coding and non-coding sequences. This discrimination is often based (thus dependent on the availability of annotated proteins. Results In this paper we present the results of a comprehensive comparison of human and mouse genomes performed with a new high throughput grid-based system which allows the rapid detection of conserved sequences and accurate assessment of their coding potential. By detecting clusters of coding conserved sequences the system is also suitable to accurately identify potential gene loci. Following this analysis we created a collection of human-mouse conserved sequence tags and carefully compared our results to reliable annotations in order to benchmark the reliability of our classifications. Strikingly we were able to detect several potential gene loci supported by EST sequences but not corresponding to as yet annotated genes. Conclusion Here we present a new system which allows comprehensive comparison of genomes to detect conserved coding and non-coding sequences and the identification of potential gene loci. Our system does not require the availability of any annotated sequence thus is suitable for the analysis of new or poorly annotated genomes.

Deep sequencing discovery of novel and conserved microRNAs in trifoliate orange (Citrus trifoliata

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Yu Huaping

2010-07-01

Full Text Available Abstract Background MicroRNAs (miRNAs play a critical role in post-transcriptional gene regulation and have been shown to control many genes involved in various biological and metabolic processes. There have been extensive studies to discover miRNAs and analyze their functions in model plant species, such as Arabidopsis and rice. Deep sequencing technologies have facilitated identification of species-specific or lowly expressed as well as conserved or highly expressed miRNAs in plants. Results In this research, we used Solexa sequencing to discover new microRNAs in trifoliate orange (Citrus trifoliata which is an important rootstock of citrus. A total of 13,106,753 reads representing 4,876,395 distinct sequences were obtained from a short RNA library generated from small RNA extracted from C. trifoliata flower and fruit tissues. Based on sequence similarity and hairpin structure prediction, we found that 156,639 reads representing 63 sequences from 42 highly conserved miRNA families, have perfect matches to known miRNAs. We also identified 10 novel miRNA candidates whose precursors were all potentially generated from citrus ESTs. In addition, five miRNA* sequences were also sequenced. These sequences had not been earlier described in other plant species and accumulation of the 10 novel miRNAs were confirmed by qRT-PCR analysis. Potential target genes were predicted for most conserved and novel miRNAs. Moreover, four target genes including one encoding IRX12 copper ion binding/oxidoreductase and three genes encoding NB-LRR disease resistance protein have been experimentally verified by detection of the miRNA-mediated mRNA cleavage in C. trifoliata. Conclusion Deep sequencing of short RNAs from C. trifoliata flowers and fruits identified 10 new potential miRNAs and 42 highly conserved miRNA families, indicating that specific miRNAs exist in C. trifoliata. These results show that regulatory miRNAs exist in agronomically important trifoliate orange

Remarkable sequence conservation of the last intron in the PKD1 gene.

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Rodova, Marianna; Islam, M Rafiq; Peterson, Kenneth R; Calvet, James P

2003-10-01

The last intron of the PKD1 gene (intron 45) was found to have exceptionally high sequence conservation across four mammalian species: human, mouse, rat, and dog. This conservation did not extend to the comparable intron in pufferfish. Pairwise comparisons for intron 45 showed 91% identity (human vs. dog) to 100% identity (mouse vs. rat) for an average for all four species of 94% identity. In contrast, introns 43 and 44 of the PKD1 gene had average pairwise identities of 57% and 54%, and exons 43, 44, and 45 and the coding region of exon 46 had average pairwise identities of 80%, 84%, 82%, and 80%. Intron 45 is 90 to 95 bp in length, with the major region of sequence divergence being in a central 4-bp to 9-bp variable region. RNA secondary structure analysis of intron 45 predicts a branching stem-loop structure in which the central variable region lies in one loop and the putative branch point sequence lies in another loop, suggesting that the intron adopts a specific stem-loop structure that may be important for its removal. Although intron 45 appears to conform to the class of small, G-triplet-containing introns that are spliced by a mechanism utilizing intron definition, its high sequence conservation may be a reflection of constraints imposed by a unique mechanism that coordinates splicing of this last PKD1 intron with polyadenylation.

Extreme sequence divergence but conserved ligand-binding specificity in Streptococcus pyogenes M protein.

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2006-05-01

Full Text Available Many pathogenic microorganisms evade host immunity through extensive sequence variability in a protein region targeted by protective antibodies. In spite of the sequence variability, a variable region commonly retains an important ligand-binding function, reflected in the presence of a highly conserved sequence motif. Here, we analyze the limits of sequence divergence in a ligand-binding region by characterizing the hypervariable region (HVR of Streptococcus pyogenes M protein. Our studies were focused on HVRs that bind the human complement regulator C4b-binding protein (C4BP, a ligand that confers phagocytosis resistance. A previous comparison of C4BP-binding HVRs identified residue identities that could be part of a binding motif, but the extended analysis reported here shows that no residue identities remain when additional C4BP-binding HVRs are included. Characterization of the HVR in the M22 protein indicated that two relatively conserved Leu residues are essential for C4BP binding, but these residues are probably core residues in a coiled-coil, implying that they do not directly contribute to binding. In contrast, substitution of either of two relatively conserved Glu residues, predicted to be solvent-exposed, had no effect on C4BP binding, although each of these changes had a major effect on the antigenic properties of the HVR. Together, these findings show that HVRs of M proteins have an extraordinary capacity for sequence divergence and antigenic variability while retaining a specific ligand-binding function.

Comparative analyses of six solanaceous transcriptomes reveal a high degree of sequence conservation and species-specific transcripts

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Ouyang Shu

2005-09-01

Full Text Available Abstract Background The Solanaceae is a family of closely related species with diverse phenotypes that have been exploited for agronomic purposes. Previous studies involving a small number of genes suggested sequence conservation across the Solanaceae. The availability of large collections of Expressed Sequence Tags (ESTs for the Solanaceae now provides the opportunity to assess sequence conservation and divergence on a genomic scale. Results All available ESTs and Expressed Transcripts (ETs, 449,224 sequences for six Solanaceae species (potato, tomato, pepper, petunia, tobacco and Nicotiana benthamiana, were clustered and assembled into gene indices. Examination of gene ontologies revealed that the transcripts within the gene indices encode a similar suite of biological processes. Although the ESTs and ETs were derived from a variety of tissues, 55–81% of the sequences had significant similarity at the nucleotide level with sequences among the six species. Putative orthologs could be identified for 28–58% of the sequences. This high degree of sequence conservation was supported by expression profiling using heterologous hybridizations to potato cDNA arrays that showed similar expression patterns in mature leaves for all six solanaceous species. 16–19% of the transcripts within the six Solanaceae gene indices did not have matches among Solanaceae, Arabidopsis, rice or 21 other plant gene indices. Conclusion Results from this genome scale analysis confirmed a high level of sequence conservation at the nucleotide level of the coding sequence among Solanaceae. Additionally, the results indicated that part of the Solanaceae transcriptome is likely to be unique for each species.

Next generation sequencing and analysis of a conserved transcriptome of New Zealand's kiwi.

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Subramanian, Sankar; Huynen, Leon; Millar, Craig D; Lambert, David M

2010-12-15

Kiwi is a highly distinctive, flightless and endangered ratite bird endemic to New Zealand. To understand the patterns of molecular evolution of the nuclear protein-coding genes in brown kiwi (Apteryx australis mantelli) and to determine the timescale of avian history we sequenced a transcriptome obtained from a kiwi embryo using next generation sequencing methods. We then assembled the conserved protein-coding regions using the chicken proteome as a scaffold. Using 1,543 conserved protein coding genes we estimated the neutral evolutionary divergence between the kiwi and chicken to be ~45%, which is approximately equal to the divergence computed for the human-mouse pair using the same set of genes. A large fraction of genes was found to be under high selective constraint, as most of the expressed genes appeared to be involved in developmental gene regulation. Our study suggests a significant relationship between gene expression levels and protein evolution. Using sequences from over 700 nuclear genes we estimated the divergence between the two basal avian groups, Palaeognathae and Neognathae to be 132 million years, which is consistent with previous studies using mitochondrial genes. The results of this investigation revealed patterns of mutation and purifying selection in conserved protein coding regions in birds. Furthermore this study suggests a relatively cost-effective way of obtaining a glimpse into the fundamental molecular evolutionary attributes of a genome, particularly when no closely related genomic sequence is available.

Next generation sequencing and analysis of a conserved transcriptome of New Zealand's kiwi

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Huynen Leon

2010-12-01

Full Text Available Abstract Background Kiwi is a highly distinctive, flightless and endangered ratite bird endemic to New Zealand. To understand the patterns of molecular evolution of the nuclear protein-coding genes in brown kiwi (Apteryx australis mantelli and to determine the timescale of avian history we sequenced a transcriptome obtained from a kiwi embryo using next generation sequencing methods. We then assembled the conserved protein-coding regions using the chicken proteome as a scaffold. Results Using 1,543 conserved protein coding genes we estimated the neutral evolutionary divergence between the kiwi and chicken to be ~45%, which is approximately equal to the divergence computed for the human-mouse pair using the same set of genes. A large fraction of genes was found to be under high selective constraint, as most of the expressed genes appeared to be involved in developmental gene regulation. Our study suggests a significant relationship between gene expression levels and protein evolution. Using sequences from over 700 nuclear genes we estimated the divergence between the two basal avian groups, Palaeognathae and Neognathae to be 132 million years, which is consistent with previous studies using mitochondrial genes. Conclusions The results of this investigation revealed patterns of mutation and purifying selection in conserved protein coding regions in birds. Furthermore this study suggests a relatively cost-effective way of obtaining a glimpse into the fundamental molecular evolutionary attributes of a genome, particularly when no closely related genomic sequence is available.

Metazoan Remaining Genes for Essential Amino Acid Biosynthesis: Sequence Conservation and Evolutionary Analyses

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Igor R. Costa

2014-12-01

Full Text Available Essential amino acids (EAA consist of a group of nine amino acids that animals are unable to synthesize via de novo pathways. Recently, it has been found that most metazoans lack the same set of enzymes responsible for the de novo EAA biosynthesis. Here we investigate the sequence conservation and evolution of all the metazoan remaining genes for EAA pathways. Initially, the set of all 49 enzymes responsible for the EAA de novo biosynthesis in yeast was retrieved. These enzymes were used as BLAST queries to search for similar sequences in a database containing 10 complete metazoan genomes. Eight enzymes typically attributed to EAA pathways were found to be ubiquitous in metazoan genomes, suggesting a conserved functional role. In this study, we address the question of how these genes evolved after losing their pathway partners. To do this, we compared metazoan genes with their fungal and plant orthologs. Using phylogenetic analysis with maximum likelihood, we found that acetolactate synthase (ALS and betaine-homocysteine S-methyltransferase (BHMT diverged from the expected Tree of Life (ToL relationships. High sequence conservation in the paraphyletic group Plant-Fungi was identified for these two genes using a newly developed Python algorithm. Selective pressure analysis of ALS and BHMT protein sequences showed higher non-synonymous mutation ratios in comparisons between metazoans/fungi and metazoans/plants, supporting the hypothesis that these two genes have undergone non-ToL evolution in animals.

HMMerThread: detecting remote, functional conserved domains in entire genomes by combining relaxed sequence-database searches with fold recognition.

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Charles Richard Bradshaw

Full Text Available Conserved domains in proteins are one of the major sources of functional information for experimental design and genome-level annotation. Though search tools for conserved domain databases such as Hidden Markov Models (HMMs are sensitive in detecting conserved domains in proteins when they share sufficient sequence similarity, they tend to miss more divergent family members, as they lack a reliable statistical framework for the detection of low sequence similarity. We have developed a greatly improved HMMerThread algorithm that can detect remotely conserved domains in highly divergent sequences. HMMerThread combines relaxed conserved domain searches with fold recognition to eliminate false positive, sequence-based identifications. With an accuracy of 90%, our software is able to automatically predict highly divergent members of conserved domain families with an associated 3-dimensional structure. We give additional confidence to our predictions by validation across species. We have run HMMerThread searches on eight proteomes including human and present a rich resource of remotely conserved domains, which adds significantly to the functional annotation of entire proteomes. We find ∼4500 cross-species validated, remotely conserved domain predictions in the human proteome alone. As an example, we find a DNA-binding domain in the C-terminal part of the A-kinase anchor protein 10 (AKAP10, a PKA adaptor that has been implicated in cardiac arrhythmias and premature cardiac death, which upon stress likely translocates from mitochondria to the nucleus/nucleolus. Based on our prediction, we propose that with this HLH-domain, AKAP10 is involved in the transcriptional control of stress response. Further remotely conserved domains we discuss are examples from areas such as sporulation, chromosome segregation and signalling during immune response. The HMMerThread algorithm is able to automatically detect the presence of remotely conserved domains in

Conserved antigenic sites between MERS-CoV and Bat-coronavirus are revealed through sequence analysis.

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Sharmin, Refat; Islam, Abul B M M K

2016-01-01

MERS-CoV is a newly emerged human coronavirus reported closely related with HKU4 and HKU5 Bat coronaviruses. Bat and MERS corona-viruses are structurally related. Therefore, it is of interest to estimate the degree of conserved antigenic sites among them. It is of importance to elucidate the shared antigenic-sites and extent of conservation between them to understand the evolutionary dynamics of MERS-CoV. Multiple sequence alignment of the spike (S), membrane (M), enveloped (E) and nucleocapsid (N) proteins was employed to identify the sequence conservation among MERS and Bat (HKU4, HKU5) coronaviruses. We used various in silico tools to predict the conserved antigenic sites. We found that MERS-CoV shared 30 % of its S protein antigenic sites with HKU4 and 70 % with HKU5 bat-CoV. Whereas 100 % of its E, M and N protein's antigenic sites are found to be conserved with those in HKU4 and HKU5. This sharing suggests that in case of pathogenicity MERS-CoV is more closely related to HKU5 bat-CoV than HKU4 bat-CoV. The conserved epitopes indicates their evolutionary relationship and ancestry of pathogenicity.

Sequence recombination and conservation of Varroa destructor virus-1 and deformed wing virus in field collected honey bees (Apis mellifera.

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Hui Wang

Full Text Available We sequenced small (s RNAs from field collected honeybees (Apis mellifera and bumblebees (Bombuspascuorum using the Illumina technology. The sRNA reads were assembled and resulting contigs were used to search for virus homologues in GenBank. Matches with Varroadestructor virus-1 (VDV1 and Deformed wing virus (DWV genomic sequences were obtained for A. mellifera but not B. pascuorum. Further analyses suggested that the prevalent virus population was composed of VDV-1 and a chimera of 5'-DWV-VDV1-DWV-3'. The recombination junctions in the chimera genomes were confirmed by using RT-PCR, cDNA cloning and Sanger sequencing. We then focused on conserved short fragments (CSF, size > 25 nt in the virus genomes by using GenBank sequences and the deep sequencing data obtained in this study. The majority of CSF sites confirmed conservation at both between-species (GenBank sequences and within-population (dataset of this study levels. However, conserved nucleotide positions in the GenBank sequences might be variable at the within-population level. High mutation rates (Pi>10% were observed at a number of sites using the deep sequencing data, suggesting that sequence conservation might not always be maintained at the population level. Virus-host interactions and strategies for developing RNAi treatments against VDV1/DWV infections are discussed.

Relationships between residue Voronoi volume and sequence conservation in proteins.

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Liu, Jen-Wei; Cheng, Chih-Wen; Lin, Yu-Feng; Chen, Shao-Yu; Hwang, Jenn-Kang; Yen, Shih-Chung

2018-02-01

Functional and biophysical constraints can cause different levels of sequence conservation in proteins. Previously, structural properties, e.g., relative solvent accessibility (RSA) and packing density of the weighted contact number (WCN), have been found to be related to protein sequence conservation (CS). The Voronoi volume has recently been recognized as a new structural property of the local protein structural environment reflecting CS. However, for surface residues, it is sensitive to water molecules surrounding the protein structure. Herein, we present a simple structural determinant termed the relative space of Voronoi volume (RSV); it uses the Voronoi volume and the van der Waals volume of particular residues to quantify the local structural environment. RSV (range, 0-1) is defined as (Voronoi volume-van der Waals volume)/Voronoi volume of the target residue. The concept of RSV describes the extent of available space for every protein residue. RSV and Voronoi profiles with and without water molecules (RSVw, RSV, VOw, and VO) were compared for 554 non-homologous proteins. RSV (without water) showed better Pearson's correlations with CS than did RSVw, VO, or VOw values. The mean correlation coefficient between RSV and CS was 0.51, which is comparable to the correlation between RSA and CS (0.49) and that between WCN and CS (0.56). RSV is a robust structural descriptor with and without water molecules and can quantitatively reflect evolutionary information in a single protein structure. Therefore, it may represent a practical structural determinant to study protein sequence, structure, and function relationships. Copyright © 2017 Elsevier B.V. All rights reserved.

Discovery and profiling of novel and conserved microRNAs during flower development in Carya cathayensis via deep sequencing.

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Wang, Zheng Jia; Huang, Jian Qin; Huang, You Jun; Li, Zheng; Zheng, Bing Song

2012-08-01

Hickory (Carya cathayensis Sarg.) is an economically important woody plant in China, but its long juvenile phase delays yield. MicroRNAs (miRNAs) are critical regulators of genes and important for normal plant development and physiology, including flower development. We used Solexa technology to sequence two small RNA libraries from two floral differentiation stages in hickory to identify miRNAs related to flower development. We identified 39 conserved miRNA sequences from 114 loci belonging to 23 families as well as two novel and ten potential novel miRNAs belonging to nine families. Moreover, 35 conserved miRNA*s and two novel miRNA*s were detected. Twenty miRNA sequences from 49 loci belonging to 11 families were differentially expressed; all were up-regulated at the later stage of flower development in hickory. Quantitative real-time PCR of 12 conserved miRNA sequences, five novel miRNA families, and two novel miRNA*s validated that all were expressed during hickory flower development, and the expression patterns were similar to those detected with Solexa sequencing. Finally, a total of 146 targets of the novel and conserved miRNAs were predicted. This study identified a diverse set of miRNAs that were closely related to hickory flower development and that could help in plant floral induction.

A ChIP-Seq benchmark shows that sequence conservation mainly improves detection of strong transcription factor binding sites.

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Tony Håndstad

Full Text Available BACKGROUND: Transcription factors are important controllers of gene expression and mapping transcription factor binding sites (TFBS is key to inferring transcription factor regulatory networks. Several methods for predicting TFBS exist, but there are no standard genome-wide datasets on which to assess the performance of these prediction methods. Also, it is believed that information about sequence conservation across different genomes can generally improve accuracy of motif-based predictors, but it is not clear under what circumstances use of conservation is most beneficial. RESULTS: Here we use published ChIP-seq data and an improved peak detection method to create comprehensive benchmark datasets for prediction methods which use known descriptors or binding motifs to detect TFBS in genomic sequences. We use this benchmark to assess the performance of five different prediction methods and find that the methods that use information about sequence conservation generally perform better than simpler motif-scanning methods. The difference is greater on high-affinity peaks and when using short and information-poor motifs. However, if the motifs are specific and information-rich, we find that simple motif-scanning methods can perform better than conservation-based methods. CONCLUSIONS: Our benchmark provides a comprehensive test that can be used to rank the relative performance of transcription factor binding site prediction methods. Moreover, our results show that, contrary to previous reports, sequence conservation is better suited for predicting strong than weak transcription factor binding sites.

Sequence analysis of the L protein of the Ebola 2014 outbreak: Insight into conserved regions and mutations.

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Ayub, Gohar; Waheed, Yasir

2016-06-01

The 2014 Ebola outbreak was one of the largest that have occurred; it started in Guinea and spread to Nigeria, Liberia and Sierra Leone. Phylogenetic analysis of the current virus species indicated that this outbreak is the result of a divergent lineage of the Zaire ebolavirus. The L protein of Ebola virus (EBOV) is the catalytic subunit of the RNA‑dependent RNA polymerase complex, which, with VP35, is key for the replication and transcription of viral RNA. Earlier sequence analysis demonstrated that the L protein of all non‑segmented negative‑sense (NNS) RNA viruses consists of six domains containing conserved functional motifs. The aim of the present study was to analyze the presence of these motifs in 2014 EBOV isolates, highlight their function and how they may contribute to the overall pathogenicity of the isolates. For this purpose, 81 2014 EBOV L protein sequences were aligned with 475 other NNS RNA viruses, including Paramyxoviridae and Rhabdoviridae viruses. Phylogenetic analysis of all EBOV outbreak L protein sequences was also performed. Analysis of the amino acid substitutions in the 2014 EBOV outbreak was conducted using sequence analysis. The alignment demonstrated the presence of previously conserved motifs in the 2014 EBOV isolates and novel residues. Notably, all the mutations identified in the 2014 EBOV isolates were tolerant, they were pathogenic with certain examples occurring within previously determined functional conserved motifs, possibly altering viral pathogenicity, replication and virulence. The phylogenetic analysis demonstrated that all sequences with the exception of the 2014 EBOV sequences were clustered together. The 2014 EBOV outbreak has acquired a great number of mutations, which may explain the reasons behind this unprecedented outbreak. Certain residues critical to the function of the polymerase remain conserved and may be targets for the development of antiviral therapeutic agents.

Sequence and structural analysis of the chitinase insertion domain reveals two conserved motifs involved in chitin-binding.

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Hai Li

2010-01-01

Full Text Available Chitinases are prevalent in life and are found in species including archaea, bacteria, fungi, plants, and animals. They break down chitin, which is the second most abundant carbohydrate in nature after cellulose. Hence, they are important for maintaining a balance between carbon and nitrogen trapped as insoluble chitin in biomass. Chitinases are classified into two families, 18 and 19 glycoside hydrolases. In addition to a catalytic domain, which is a triosephosphate isomerase barrel, many family 18 chitinases contain another module, i.e., chitinase insertion domain. While numerous studies focus on the biological role of the catalytic domain in chitinase activity, the function of the chitinase insertion domain is not completely understood. Bioinformatics offers an important avenue in which to facilitate understanding the role of residues within the chitinase insertion domain in chitinase function.Twenty-seven chitinase insertion domain sequences, which include four experimentally determined structures and span five kingdoms, were aligned and analyzed using a modified sequence entropy parameter. Thirty-two positions with conserved residues were identified. The role of these conserved residues was explored by conducting a structural analysis of a number of holo-enzymes. Hydrogen bonding and van der Waals calculations revealed a distinct subset of four conserved residues constituting two sequence motifs that interact with oligosaccharides. The other conserved residues may be key to the structure, folding, and stability of this domain.Sequence and structural studies of the chitinase insertion domains conducted within the framework of evolution identified four conserved residues which clearly interact with the substrates. Furthermore, evolutionary studies propose a link between the appearance of the chitinase insertion domain and the function of family 18 chitinases in the subfamily A.

A unique genomic sequence in the Wolf-Hirschhorn syndrome [WHS] region of humans is conserved in the great apes.

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Tarzami, S T; Kringstein, A M; Conte, R A; Verma, R S

1996-10-01

The Wolf-Hirschhorn syndrome (WHS) is caused by a partial deletion in the short arm of chromosome 4 band 16.3 (4p 16.3). A unique-sequence human DNA probe (39 kb) localized within this region has been used to search for sequence homology in the apes' equivalent chromosome 3 by FISH-technique. The WHS loci are conserved in higher primates at the expected position. Nevertheless, a control probe, which detects alphoid sequences of the pericentromeric region of humans, is diverged in chimpanzee, gorilla, and orangutan. The conservation of WHS loci and divergence of DNA alphoid sequences have further added to the controversy concerning human descent.

Sample sequencing of vascular plants demonstrates widespread conservation and divergence of microRNAs.

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Chávez Montes, Ricardo A; de Fátima Rosas-Cárdenas, Flor; De Paoli, Emanuele; Accerbi, Monica; Rymarquis, Linda A; Mahalingam, Gayathri; Marsch-Martínez, Nayelli; Meyers, Blake C; Green, Pamela J; de Folter, Stefan

2014-04-23

Small RNAs are pivotal regulators of gene expression that guide transcriptional and post-transcriptional silencing mechanisms in eukaryotes, including plants. Here we report a comprehensive atlas of sRNA and miRNA from 3 species of algae and 31 representative species across vascular plants, including non-model plants. We sequence and quantify sRNAs from 99 different tissues or treatments across species, resulting in a data set of over 132 million distinct sequences. Using miRBase mature sequences as a reference, we identify the miRNA sequences present in these libraries. We apply diverse profiling methods to examine critical sRNA and miRNA features, such as size distribution, tissue-specific regulation and sequence conservation between species, as well as to predict putative new miRNA sequences. We also develop database resources, computational analysis tools and a dedicated website, http://smallrna.udel.edu/. This study provides new insights on plant sRNAs and miRNAs, and a foundation for future studies.

High-throughput sequencing, characterization and detection of new and conserved cucumber miRNAs.

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Germán Martínez

Full Text Available Micro RNAS (miRNAs are a class of endogenous small non coding RNAs involved in the post-transcriptional regulation of gene expression. In plants, a great number of conserved and specific miRNAs, mainly arising from model species, have been identified to date. However less is known about the diversity of these regulatory RNAs in vegetal species with agricultural and/or horticultural importance. Here we report a combined approach of bioinformatics prediction, high-throughput sequencing data and molecular methods to analyze miRNAs populations in cucumber (Cucumis sativus plants. A set of 19 conserved and 6 known but non-conserved miRNA families were found in our cucumber small RNA dataset. We also identified 7 (3 with their miRNA* strand not previously described miRNAs, candidates to be cucumber-specific. To validate their description these new C. sativus miRNAs were detected by northern blot hybridization. Additionally, potential targets for most conserved and new miRNAs were identified in cucumber genome.In summary, in this study we have identified, by first time, conserved, known non-conserved and new miRNAs arising from an agronomically important species such as C. sativus. The detection of this complex population of regulatory small RNAs suggests that similarly to that observe in other plant species, cucumber miRNAs may possibly play an important role in diverse biological and metabolic processes.

Identification of evolutionarily conserved non-AUG-initiated N-terminal extensions in human coding sequences.

LENUS (Irish Health Repository)

Ivanov, Ivaylo P

2011-05-01

In eukaryotes, it is generally assumed that translation initiation occurs at the AUG codon closest to the messenger RNA 5\\' cap. However, in certain cases, initiation can occur at codons differing from AUG by a single nucleotide, especially the codons CUG, UUG, GUG, ACG, AUA and AUU. While non-AUG initiation has been experimentally verified for a handful of human genes, the full extent to which this phenomenon is utilized--both for increased coding capacity and potentially also for novel regulatory mechanisms--remains unclear. To address this issue, and hence to improve the quality of existing coding sequence annotations, we developed a methodology based on phylogenetic analysis of predicted 5\\' untranslated regions from orthologous genes. We use evolutionary signatures of protein-coding sequences as an indicator of translation initiation upstream of annotated coding sequences. Our search identified novel conserved potential non-AUG-initiated N-terminal extensions in 42 human genes including VANGL2, FGFR1, KCNN4, TRPV6, HDGF, CITED2, EIF4G3 and NTF3, and also affirmed the conservation of known non-AUG-initiated extensions in 17 other genes. In several instances, we have been able to obtain independent experimental evidence of the expression of non-AUG-initiated products from the previously published literature and ribosome profiling data.

Genome-wide discovery and differential regulation of conserved and novel microRNAs in chickpea via deep sequencing.

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Jain, Mukesh; Chevala, V V S Narayana; Garg, Rohini

2014-11-01

MicroRNAs (miRNAs) are essential components of complex gene regulatory networks that orchestrate plant development. Although several genomic resources have been developed for the legume crop chickpea, miRNAs have not been discovered until now. For genome-wide discovery of miRNAs in chickpea (Cicer arietinum), we sequenced the small RNA content from seven major tissues/organs employing Illumina technology. About 154 million reads were generated, which represented more than 20 million distinct small RNA sequences. We identified a total of 440 conserved miRNAs in chickpea based on sequence similarity with known miRNAs in other plants. In addition, 178 novel miRNAs were identified using a miRDeep pipeline with plant-specific scoring. Some of the conserved and novel miRNAs with significant sequence similarity were grouped into families. The chickpea miRNAs targeted a wide range of mRNAs involved in diverse cellular processes, including transcriptional regulation (transcription factors), protein modification and turnover, signal transduction, and metabolism. Our analysis revealed several miRNAs with differential spatial expression. Many of the chickpea miRNAs were expressed in a tissue-specific manner. The conserved and differential expression of members of the same miRNA family in different tissues was also observed. Some of the same family members were predicted to target different chickpea mRNAs, which suggested the specificity and complexity of miRNA-mediated developmental regulation. This study, for the first time, reveals a comprehensive set of conserved and novel miRNAs along with their expression patterns and putative targets in chickpea, and provides a framework for understanding regulation of developmental processes in legumes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

JDet: interactive calculation and visualization of function-related conservation patterns in multiple sequence alignments and structures.

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Muth, Thilo; García-Martín, Juan A; Rausell, Antonio; Juan, David; Valencia, Alfonso; Pazos, Florencio

2012-02-15

We have implemented in a single package all the features required for extracting, visualizing and manipulating fully conserved positions as well as those with a family-dependent conservation pattern in multiple sequence alignments. The program allows, among other things, to run different methods for extracting these positions, combine the results and visualize them in protein 3D structures and sequence spaces. JDet is a multiplatform application written in Java. It is freely available, including the source code, at http://csbg.cnb.csic.es/JDet. The package includes two of our recently developed programs for detecting functional positions in protein alignments (Xdet and S3Det), and support for other methods can be added as plug-ins. A help file and a guided tutorial for JDet are also available.

How conserved are the conserved 16S-rRNA regions?

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Marcel Martinez-Porchas

2017-02-01

Full Text Available The 16S rRNA gene has been used as master key for studying prokaryotic diversity in almost every environment. Despite the claim of several researchers to have the best universal primers, the reality is that no primer has been demonstrated to be truly universal. This suggests that conserved regions of the gene may not be as conserved as expected. The aim of this study was to evaluate the conservation degree of the so-called conserved regions flanking the hypervariable regions of the 16S rRNA gene. Data contained in SILVA database (release 123 were used for the study. Primers reported as matches of each conserved region were assembled to form contigs; sequences sizing 12 nucleotides (12-mers were extracted from these contigs and searched into the entire set of SILVA sequences. Frequency analysis shown that extreme regions, 1 and 10, registered the lowest frequencies. 12-mer frequencies revealed segments of contigs that were not as conserved as expected (≤90%. Fragments corresponding to the primer contigs 3, 4, 5b and 6a were recovered from all sequences in SILVA database. Nucleotide frequency analysis in each consensus demonstrated that only a small fraction of these so-called conserved regions is truly conserved in non-redundant sequences. It could be concluded that conserved regions of the 16S rRNA gene exhibit considerable variation that has to be considered when using this gene as biomarker.

T-cell recognition is shaped by epitope sequence conservation in the host proteome and microbiome

DEFF Research Database (Denmark)

Bresciani, Anne Gøther; Paul, Sinu; Schommer, Nina

2016-01-01

or allergen with the conservation of its sequence in the human proteome or the healthy human microbiome. Indeed, performing such comparisons on large sets of validated T-cell epitopes, we found that epitopes that are similar with self-antigens above a certain threshold showed lower immunogenicity, presumably...... as a result of negative selection of T cells capable of recognizing such peptides. Moreover, we also found a reduced level of immune recognition for epitopes conserved in the commensal microbiome, presumably as a result of peripheral tolerance. These findings indicate that the existence (and potentially...

Sequence, structure and function relationships in flaviviruses as assessed by evolutive aspects of its conserved non-structural protein domains.

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da Fonseca, Néli José; Lima Afonso, Marcelo Querino; Pedersolli, Natan Gonçalves; de Oliveira, Lucas Carrijo; Andrade, Dhiego Souto; Bleicher, Lucas

2017-10-28

Flaviviruses are responsible for serious diseases such as dengue, yellow fever, and zika fever. Their genomes encode a polyprotein which, after cleavage, results in three structural and seven non-structural proteins. Homologous proteins can be studied by conservation and coevolution analysis as detected in multiple sequence alignments, usually reporting positions which are strictly necessary for the structure and/or function of all members in a protein family or which are involved in a specific sub-class feature requiring the coevolution of residue sets. This study provides a complete conservation and coevolution analysis on all flaviviruses non-structural proteins, with results mapped on all well-annotated available sequences. A literature review on the residues found in the analysis enabled us to compile available information on their roles and distribution among different flaviviruses. Also, we provide the mapping of conserved and coevolved residues for all sequences currently in SwissProt as a supplementary material, so that particularities in different viruses can be easily analyzed. Copyright © 2017 Elsevier Inc. All rights reserved.

Asymmetrical distribution of non-conserved regulatory sequences at PHOX2B is reflected at the ENCODE loci and illuminates a possible genome-wide trend

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McCallion Andrew S

2009-01-01

Full Text Available Abstract Background Transcriptional regulatory elements are central to development and interspecific phenotypic variation. Current regulatory element prediction tools rely heavily upon conservation for prediction of putative elements. Recent in vitro observations from the ENCODE project combined with in vivo analyses at the zebrafish phox2b locus suggests that a significant fraction of regulatory elements may fall below commonly applied metrics of conservation. We propose to explore these observations in vivo at the human PHOX2B locus, and also evaluate the potential evidence for genome-wide applicability of these observations through a novel analysis of extant data. Results Transposon-based transgenic analysis utilizing a tiling path proximal to human PHOX2B in zebrafish recapitulates the observations at the zebrafish phox2b locus of both conserved and non-conserved regulatory elements. Analysis of human sequences conserved with previously identified zebrafish phox2b regulatory elements demonstrates that the orthologous sequences exhibit overlapping regulatory control. Additionally, analysis of non-conserved sequences scattered over 135 kb 5' to PHOX2B, provides evidence of non-conserved regulatory elements positively biased with close proximity to the gene. Furthermore, we provide a novel analysis of data from the ENCODE project, finding a non-uniform distribution of regulatory elements consistent with our in vivo observations at PHOX2B. These observations remain largely unchanged when one accounts for the sequence repeat content of the assayed intervals, when the intervals are sub-classified by biological role (developmental versus non-developmental, or by gene density (gene desert versus non-gene desert. Conclusion While regulatory elements frequently display evidence of evolutionary conservation, a fraction appears to be undetected by current metrics of conservation. In vivo observations at the PHOX2B locus, supported by our analyses of in

A Potential Tool for Swift Fox (Vulpes velox) Conservation: Individuality of Long-Range Barking Sequences

DEFF Research Database (Denmark)

Darden, Safi-Kirstine Klem; Dabelsteen, Torben; Pedersen, Simon Boel

2003-01-01

Vocal individuality has been found in a number canid species. This natural variation can have applications in several aspects of species conservation, from behavioral studies to estimating population density or abundance. The swift fox (Vulpes velox) is a North American canid listed as endangered...... in Canada and extirpated, endangered, or threatened in parts of the United States. The barking sequence is a long-range vocalization in the species' vocal repertoire. It consists of a series of barks and is most common during the mating season. We analyzed barking sequences recorded in a standardized...

The Number, Organization, and Size of Polymorphic Membrane Protein Coding Sequences as well as the Most Conserved Pmp Protein Differ within and across Chlamydia Species.

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Van Lent, Sarah; Creasy, Heather Huot; Myers, Garry S A; Vanrompay, Daisy

2016-01-01

Variation is a central trait of the polymorphic membrane protein (Pmp) family. The number of pmp coding sequences differs between Chlamydia species, but it is unknown whether the number of pmp coding sequences is constant within a Chlamydia species. The level of conservation of the Pmp proteins has previously only been determined for Chlamydia trachomatis. As different Pmp proteins might be indispensible for the pathogenesis of different Chlamydia species, this study investigated the conservation of Pmp proteins both within and across C. trachomatis,C. pneumoniae,C. abortus, and C. psittaci. The pmp coding sequences were annotated in 16 C. trachomatis, 6 C. pneumoniae, 2 C. abortus, and 16 C. psittaci genomes. The number and organization of polymorphic membrane coding sequences differed within and across the analyzed Chlamydia species. The length of coding sequences of pmpA,pmpB, and pmpH was conserved among all analyzed genomes, while the length of pmpE/F and pmpG, and remarkably also of the subtype pmpD, differed among the analyzed genomes. PmpD, PmpA, PmpH, and PmpA were the most conserved Pmp in C. trachomatis,C. pneumoniae,C. abortus, and C. psittaci, respectively. PmpB was the most conserved Pmp across the 4 analyzed Chlamydia species. © 2016 S. Karger AG, Basel.

Some AFLP amplicons are highly conserved DNA sequences mapping to the same linkage groups in two F2 populations of carrot

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Santos Carlos A.F.

2002-01-01

Full Text Available Amplified fragment length polymorphism (AFLP is a fast and reliable tool to generate a large number of DNA markers. In two unrelated F2 populations of carrot (Daucus carota L., Brasilia x HCM and B493 x QAL (wild carrot, it was hypothesized that DNA 1 digested with the same restriction endonuclease enzymes and amplified with the same primer combination and 2 sharing the same position in polyacrylamide gels should be conserved sequences. To test this hypothesis AFLP fragments from polyacrylamide gels were eluted, reamplified, separated in agarose gels, purified, cloned and sequenced. Among thirty-one paired fragments from each F2 population, twenty-six had identity greater than 91% and five presented identity of 24% to 44%. Among the twenty-six conserved AFLPs only one mapped to different linkage groups in the two populations while four of the five less-conserved bands mapped to different linkage groups. Of eight SCAR (sequence characterized amplified regions primers tested, one conserved AFLP resulted in co-dominant markers in both populations. Screening among 14 carrot inbreds or cultivars with three AFLP-SCAR primers revealed clear and polymorphic PCR products, with similar molecular sizes on agarose gels. The development of co-dominant markers based on conserved AFLP fragments will be useful to detect seed mixtures among hybrids, to improve and to merge linkage maps and to study diversity and phylogenetic relationships.

Effects of temperature and mass conservation on the typical chemical sequences of hydrogen oxidation

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Nicholson, Schuyler B.; Alaghemandi, Mohammad; Green, Jason R.

2018-01-01

Macroscopic properties of reacting mixtures are necessary to design synthetic strategies, determine yield, and improve the energy and atom efficiency of many chemical processes. The set of time-ordered sequences of chemical species are one representation of the evolution from reactants to products. However, only a fraction of the possible sequences is typical, having the majority of the joint probability and characterizing the succession of chemical nonequilibrium states. Here, we extend a variational measure of typicality and apply it to atomistic simulations of a model for hydrogen oxidation over a range of temperatures. We demonstrate an information-theoretic methodology to identify typical sequences under the constraints of mass conservation. Including these constraints leads to an improved ability to learn the chemical sequence mechanism from experimentally accessible data. From these typical sequences, we show that two quantities defining the variational typical set of sequences—the joint entropy rate and the topological entropy rate—increase linearly with temperature. These results suggest that, away from explosion limits, data over a narrow range of thermodynamic parameters could be sufficient to extrapolate these typical features of combustion chemistry to other conditions.

PDL1 Signals through Conserved Sequence Motifs to Overcome Interferon-Mediated Cytotoxicity

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Maria Gato-Cañas

2017-08-01

Full Text Available PDL1 blockade produces remarkable clinical responses, thought to occur by T cell reactivation through prevention of PDL1-PD1 T cell inhibitory interactions. Here, we find that PDL1 cell-intrinsic signaling protects cancer cells from interferon (IFN cytotoxicity and accelerates tumor progression. PDL1 inhibited IFN signal transduction through a conserved class of sequence motifs that mediate crosstalk with IFN signaling. Abrogation of PDL1 expression or antibody-mediated PDL1 blockade strongly sensitized cancer cells to IFN cytotoxicity through a STAT3/caspase-7-dependent pathway. Moreover, somatic mutations found in human carcinomas within these PDL1 sequence motifs disrupted motif regulation, resulting in PDL1 molecules with enhanced protective activities from type I and type II IFN cytotoxicity. Overall, our results reveal a mode of action of PDL1 in cancer cells as a first line of defense against IFN cytotoxicity.

Optimal packaging of FIV genomic RNA depends upon a conserved long-range interaction and a palindromic sequence within gag.

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Rizvi, Tahir A; Kenyon, Julia C; Ali, Jahabar; Aktar, Suriya J; Phillip, Pretty S; Ghazawi, Akela; Mustafa, Farah; Lever, Andrew M L

2010-10-15

The feline immunodeficiency virus (FIV) is a lentivirus that is related to human immunodeficiency virus (HIV), causing a similar pathology in cats. It is a potential small animal model for AIDS and the FIV-based vectors are also being pursued for human gene therapy. Previous studies have mapped the FIV packaging signal (ψ) to two or more discontinuous regions within the 5' 511 nt of the genomic RNA and structural analyses have determined its secondary structure. The 5' and 3' sequences within ψ region interact through extensive long-range interactions (LRIs), including a conserved heptanucleotide interaction between R/U5 and gag. Other secondary structural elements identified include a conserved 150 nt stem-loop (SL2) and a small palindromic stem-loop within gag open reading frame that might act as a viral dimerization initiation site. We have performed extensive mutational analysis of these sequences and structures and ascertained their importance in FIV packaging using a trans-complementation assay. Disrupting the conserved heptanucleotide LRI to prevent base pairing between R/U5 and gag reduced packaging by 2.8-5.5 fold. Restoration of pairing using an alternative, non-wild type (wt) LRI sequence restored RNA packaging and propagation to wt levels, suggesting that it is the structure of the LRI, rather than its sequence, that is important for FIV packaging. Disrupting the palindrome within gag reduced packaging by 1.5-3-fold, but substitution with a different palindromic sequence did not restore packaging completely, suggesting that the sequence of this region as well as its palindromic nature is important. Mutation of individual regions of SL2 did not have a pronounced effect on FIV packaging, suggesting that either it is the structure of SL2 as a whole that is necessary for optimal packaging, or that there is redundancy within this structure. The mutational analysis presented here has further validated the previously predicted RNA secondary structure of FIV

Lariat sequencing in a unicellular yeast identifies regulated alternative splicing of exons that are evolutionarily conserved with humans.

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Awan, Ali R; Manfredo, Amanda; Pleiss, Jeffrey A

2013-07-30

Alternative splicing is a potent regulator of gene expression that vastly increases proteomic diversity in multicellular eukaryotes and is associated with organismal complexity. Although alternative splicing is widespread in vertebrates, little is known about the evolutionary origins of this process, in part because of the absence of phylogenetically conserved events that cross major eukaryotic clades. Here we describe a lariat-sequencing approach, which offers high sensitivity for detecting splicing events, and its application to the unicellular fungus, Schizosaccharomyces pombe, an organism that shares many of the hallmarks of alternative splicing in mammalian systems but for which no previous examples of exon-skipping had been demonstrated. Over 200 previously unannotated splicing events were identified, including examples of regulated alternative splicing. Remarkably, an evolutionary analysis of four of the exons identified here as subject to skipping in S. pombe reveals high sequence conservation and perfect length conservation with their homologs in scores of plants, animals, and fungi. Moreover, alternative splicing of two of these exons have been documented in multiple vertebrate organisms, making these the first demonstrations of identical alternative-splicing patterns in species that are separated by over 1 billion y of evolution.

Detecting remote sequence homology in disordered proteins: discovery of conserved motifs in the N-termini of Mononegavirales phosphoproteins.

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David Karlin

Full Text Available Paramyxovirinae are a large group of viruses that includes measles virus and parainfluenza viruses. The viral Phosphoprotein (P plays a central role in viral replication. It is composed of a highly variable, disordered N-terminus and a conserved C-terminus. A second viral protein alternatively expressed, the V protein, also contains the N-terminus of P, fused to a zinc finger. We suspected that, despite their high variability, the N-termini of P/V might all be homologous; however, using standard approaches, we could previously identify sequence conservation only in some Paramyxovirinae. We now compared the N-termini using sensitive sequence similarity search programs, able to detect residual similarities unnoticeable by conventional approaches. We discovered that all Paramyxovirinae share a short sequence motif in their first 40 amino acids, which we called soyuz1. Despite its short length (11-16aa, several arguments allow us to conclude that soyuz1 probably evolved by homologous descent, unlike linear motifs. Conservation across such evolutionary distances suggests that soyuz1 plays a crucial role and experimental data suggest that it binds the viral nucleoprotein to prevent its illegitimate self-assembly. In some Paramyxovirinae, the N-terminus of P/V contains a second motif, soyuz2, which might play a role in blocking interferon signaling. Finally, we discovered that the P of related Mononegavirales contain similarly overlooked motifs in their N-termini, and that their C-termini share a previously unnoticed structural similarity suggesting a common origin. Our results suggest several testable hypotheses regarding the replication of Mononegavirales and suggest that disordered regions with little overall sequence similarity, common in viral and eukaryotic proteins, might contain currently overlooked motifs (intermediate in length between linear motifs and disordered domains that could be detected simply by comparing orthologous proteins.

Structure-Related Roles for the Conservation of the HIV-1 Fusion Peptide Sequence Revealed by Nuclear Magnetic Resonance.

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Serrano, Soraya; Huarte, Nerea; Rujas, Edurne; Andreu, David; Nieva, José L; Jiménez, María Angeles

2017-10-17

Despite extensive characterization of the human immunodeficiency virus type 1 (HIV-1) hydrophobic fusion peptide (FP), the structure-function relationships underlying its extraordinary degree of conservation remain poorly understood. Specifically, the fact that the tandem repeat of the FLGFLG tripeptide is absolutely conserved suggests that high hydrophobicity may not suffice to unleash FP function. Here, we have compared the nuclear magnetic resonance (NMR) structures adopted in nonpolar media by two FP surrogates, wtFP-tag and scrFP-tag, which had equal hydrophobicity but contained wild-type and scrambled core sequences LFLGFLG and FGLLGFL, respectively. In addition, these peptides were tagged at their C-termini with an epitope sequence that folded independently, thereby allowing Western blot detection without interfering with FP structure. We observed similar α-helical FP conformations for both specimens dissolved in the low-polarity medium 25% (v/v) 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), but important differences in contact with micelles of the membrane mimetic dodecylphosphocholine (DPC). Thus, whereas wtFP-tag preserved a helix displaying a Gly-rich ridge, the scrambled sequence lost in great part the helical structure upon being solubilized in DPC. Western blot analyses further revealed the capacity of wtFP-tag to assemble trimers in membranes, whereas membrane oligomers were not observed in the case of the scrFP-tag sequence. We conclude that, beyond hydrophobicity, preserving sequence order is an important feature for defining the secondary structures and oligomeric states adopted by the HIV FP in membranes.

Multi-species sequence comparison reveals conservation of ghrelin gene-derived splice variants encoding a truncated ghrelin peptide.

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Seim, Inge; Jeffery, Penny L; Thomas, Patrick B; Walpole, Carina M; Maugham, Michelle; Fung, Jenny N T; Yap, Pei-Yi; O'Keeffe, Angela J; Lai, John; Whiteside, Eliza J; Herington, Adrian C; Chopin, Lisa K

2016-06-01

The peptide hormone ghrelin is a potent orexigen produced predominantly in the stomach. It has a number of other biological actions, including roles in appetite stimulation, energy balance, the stimulation of growth hormone release and the regulation of cell proliferation. Recently, several ghrelin gene splice variants have been described. Here, we attempted to identify conserved alternative splicing of the ghrelin gene by cross-species sequence comparisons. We identified a novel human exon 2-deleted variant and provide preliminary evidence that this splice variant and in1-ghrelin encode a C-terminally truncated form of the ghrelin peptide, termed minighrelin. These variants are expressed in humans and mice, demonstrating conservation of alternative splicing spanning 90 million years. Minighrelin appears to have similar actions to full-length ghrelin, as treatment with exogenous minighrelin peptide stimulates appetite and feeding in mice. Forced expression of the exon 2-deleted preproghrelin variant mirrors the effect of the canonical preproghrelin, stimulating cell proliferation and migration in the PC3 prostate cancer cell line. This is the first study to characterise an exon 2-deleted preproghrelin variant and to demonstrate sequence conservation of ghrelin gene-derived splice variants that encode a truncated ghrelin peptide. This adds further impetus for studies into the alternative splicing of the ghrelin gene and the function of novel ghrelin peptides in vertebrates.

Analysis of 90 Mb of the potato genome reveals conservation of gene structures and order with tomato but divergence in repetitive sequence composition

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O'Brien Kimberly

2008-06-01

Full Text Available Abstract Background The Solanaceae family contains a number of important crop species including potato (Solanum tuberosum which is grown for its underground storage organ known as a tuber. Albeit the 4th most important food crop in the world, other than a collection of ~220,000 Expressed Sequence Tags, limited genomic sequence information is currently available for potato and advances in potato yield and nutrition content would be greatly assisted through access to a complete genome sequence. While morphologically diverse, Solanaceae species such as potato, tomato, pepper, and eggplant share not only genes but also gene order thereby permitting highly informative comparative genomic analyses. Results In this study, we report on analysis 89.9 Mb of potato genomic sequence representing 10.2% of the genome generated through end sequencing of a potato bacterial artificial chromosome (BAC clone library (87 Mb and sequencing of 22 potato BAC clones (2.9 Mb. The GC content of potato is very similar to Solanum lycopersicon (tomato and other dicotyledonous species yet distinct from the monocotyledonous grass species, Oryza sativa. Parallel analyses of repetitive sequences in potato and tomato revealed substantial differences in their abundance, 34.2% in potato versus 46.3% in tomato, which is consistent with the increased genome size per haploid genome of these two Solanum species. Specific classes and types of repetitive sequences were also differentially represented between these two species including a telomeric-related repetitive sequence, ribosomal DNA, and a number of unclassified repetitive sequences. Comparative analyses between tomato and potato at the gene level revealed a high level of conservation of gene content, genic feature, and gene order although discordances in synteny were observed. Conclusion Genomic level analyses of potato and tomato confirm that gene sequence and gene order are conserved between these solanaceous species and that

Functional region prediction with a set of appropriate homologous sequences-an index for sequence selection by integrating structure and sequence information with spatial statistics

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2012-01-01

Background The detection of conserved residue clusters on a protein structure is one of the effective strategies for the prediction of functional protein regions. Various methods, such as Evolutionary Trace, have been developed based on this strategy. In such approaches, the conserved residues are identified through comparisons of homologous amino acid sequences. Therefore, the selection of homologous sequences is a critical step. It is empirically known that a certain degree of sequence divergence in the set of homologous sequences is required for the identification of conserved residues. However, the development of a method to select homologous sequences appropriate for the identification of conserved residues has not been sufficiently addressed. An objective and general method to select appropriate homologous sequences is desired for the efficient prediction of functional regions. Results We have developed a novel index to select the sequences appropriate for the identification of conserved residues, and implemented the index within our method to predict the functional regions of a protein. The implementation of the index improved the performance of the functional region prediction. The index represents the degree of conserved residue clustering on the tertiary structure of the protein. For this purpose, the structure and sequence information were integrated within the index by the application of spatial statistics. Spatial statistics is a field of statistics in which not only the attributes but also the geometrical coordinates of the data are considered simultaneously. Higher degrees of clustering generate larger index scores. We adopted the set of homologous sequences with the highest index score, under the assumption that the best prediction accuracy is obtained when the degree of clustering is the maximum. The set of sequences selected by the index led to higher functional region prediction performance than the sets of sequences selected by other sequence

Conservation and diversification of Msx protein in metazoan evolution.

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Takahashi, Hirokazu; Kamiya, Akiko; Ishiguro, Akira; Suzuki, Atsushi C; Saitou, Naruya; Toyoda, Atsushi; Aruga, Jun

2008-01-01

Msx (/msh) family genes encode homeodomain (HD) proteins that control ontogeny in many animal species. We compared the structures of Msx genes from a wide range of Metazoa (Porifera, Cnidaria, Nematoda, Arthropoda, Tardigrada, Platyhelminthes, Mollusca, Brachiopoda, Annelida, Echiura, Echinodermata, Hemichordata, and Chordata) to gain an understanding of the role of these genes in phylogeny. Exon-intron boundary analysis suggested that the position of the intron located N-terminally to the HDs was widely conserved in all the genes examined, including those of cnidarians. Amino acid (aa) sequence comparison revealed 3 new evolutionarily conserved domains, as well as very strong conservation of the HDs. Two of the three domains were associated with Groucho-like protein binding in both a vertebrate and a cnidarian Msx homolog, suggesting that the interaction between Groucho-like proteins and Msx proteins was established in eumetazoan ancestors. Pairwise comparison among the collected HDs and their C-flanking aa sequences revealed that the degree of sequence conservation varied depending on the animal taxa from which the sequences were derived. Highly conserved Msx genes were identified in the Vertebrata, Cephalochordata, Hemichordata, Echinodermata, Mollusca, Brachiopoda, and Anthozoa. The wide distribution of the conserved sequences in the animal phylogenetic tree suggested that metazoan ancestors had already acquired a set of conserved domains of the current Msx family genes. Interestingly, although strongly conserved sequences were recovered from the Vertebrata, Cephalochordata, and Anthozoa, the sequences from the Urochordata and Hydrozoa showed weak conservation. Because the Vertebrata-Cephalochordata-Urochordata and Anthozoa-Hydrozoa represent sister groups in the Chordata and Cnidaria, respectively, Msx sequence diversification may have occurred differentially in the course of evolution. We speculate that selective loss of the conserved domains in Msx family

Evolutionary conservation of nuclear and nucleolar targeting sequences in yeast ribosomal protein S6A

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Lipsius, Edgar; Walter, Korden; Leicher, Torsten; Phlippen, Wolfgang; Bisotti, Marc-Angelo; Kruppa, Joachim

2005-01-01

Over 1 billion years ago, the animal kingdom diverged from the fungi. Nevertheless, a high sequence homology of 62% exists between human ribosomal protein S6 and S6A of Saccharomyces cerevisiae. To investigate whether this similarity in primary structure is mirrored in corresponding functional protein domains, the nuclear and nucleolar targeting signals were delineated in yeast S6A and compared to the known human S6 signals. The complete sequence of S6A and cDNA fragments was fused to the 5'-end of the LacZ gene, the constructs were transiently expressed in COS cells, and the subcellular localization of the fusion proteins was detected by indirect immunofluorescence. One bipartite and two monopartite nuclear localization signals as well as two nucleolar binding domains were identified in yeast S6A, which are located at homologous regions in human S6 protein. Remarkably, the number, nature, and position of these targeting signals have been conserved, albeit their amino acid sequences have presumably undergone a process of co-evolution with their corresponding rRNAs

Optimizing multiple sequence alignments using a genetic algorithm based on three objectives: structural information, non-gaps percentage and totally conserved columns.

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Ortuño, Francisco M; Valenzuela, Olga; Rojas, Fernando; Pomares, Hector; Florido, Javier P; Urquiza, Jose M; Rojas, Ignacio

2013-09-01

Multiple sequence alignments (MSAs) are widely used approaches in bioinformatics to carry out other tasks such as structure predictions, biological function analyses or phylogenetic modeling. However, current tools usually provide partially optimal alignments, as each one is focused on specific biological features. Thus, the same set of sequences can produce different alignments, above all when sequences are less similar. Consequently, researchers and biologists do not agree about which is the most suitable way to evaluate MSAs. Recent evaluations tend to use more complex scores including further biological features. Among them, 3D structures are increasingly being used to evaluate alignments. Because structures are more conserved in proteins than sequences, scores with structural information are better suited to evaluate more distant relationships between sequences. The proposed multiobjective algorithm, based on the non-dominated sorting genetic algorithm, aims to jointly optimize three objectives: STRIKE score, non-gaps percentage and totally conserved columns. It was significantly assessed on the BAliBASE benchmark according to the Kruskal-Wallis test (P algorithm also outperforms other aligners, such as ClustalW, Multiple Sequence Alignment Genetic Algorithm (MSA-GA), PRRP, DIALIGN, Hidden Markov Model Training (HMMT), Pattern-Induced Multi-sequence Alignment (PIMA), MULTIALIGN, Sequence Alignment Genetic Algorithm (SAGA), PILEUP, Rubber Band Technique Genetic Algorithm (RBT-GA) and Vertical Decomposition Genetic Algorithm (VDGA), according to the Wilcoxon signed-rank test (P 0.05) with the advantage of being able to use less structures. Structural information is included within the objective function to evaluate more accurately the obtained alignments. The source code is available at http://www.ugr.es/~fortuno/MOSAStrE/MO-SAStrE.zip.

In Vivo Characterization of a Vertebrate Ultra-conserved Enhancer

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Poulin, Francis; Nobrega, Marcelo A.; Plajzer-Frick, Ingrid; Holt, Amy; Afzal, Veena; Rubin, Edward M.; Pennacchio, Len

2004-10-01

Genomic sequence comparisons between human, mouse and pufferfish (Takifugu rubripes (Fugu))have revealed a set of extremely conserved noncoding sequences. While this high degree of sequence conservation suggests severe evolutionary constraint and predicts a lack of tolerance to change in order to retain in vivo functionality, such elements have been minimally explored experimentally. In this study, we describe the in-depth characterization of an ancient conserved enhancer, Dc2 located near the dachshund gene, which displays a human-Fugu identity of 84 percent over 424 basepairs (bp). In addition to this large overall conservation, we find that Dc2 is characterized by the presence of a large block of sequence (144 bp) that is completely identical between human, mouse, chicken, zebrafish and Fugu. Through the testing of reporter vector constructs in transgenic mice, we observed that the 424 bp Dc2 conserved element is necessary and sufficient for brain tissue enhancer activity. In vivo analyses also revealed that the 144 bp 100 percent conserved sequence is necessary, but not sufficient, to replicate Dc2 enhancer function. However, the introduction of two separate 16 bp insertions into the highly conserved enhancer core did not cause any detectable modification of its in vivo activity. Our observations indicate that the 144 bp 100 percent conserved element is tolerant of change at least at the resolution of this transgenic mouse assay and suggest that purifying selection on Dc2 sequence might not be as strong as we predicted or that some unknown property also constrains this highly conserved enhancer sequence.

Transcriptional activation signals found in the Epstein-Barr virus (EBV) latency C promoter are conserved in the latency C promoter sequences from baboon and Rhesus monkey EBV-like lymphocryptoviruses (cercopithicine herpesviruses 12 and 15).

Science.gov (United States)

Fuentes-Pananá, E M; Swaminathan, S; Ling, P D

1999-01-01

The Epstein-Barr virus (EBV) EBNA2 protein is a transcriptional activator that controls viral latent gene expression and is essential for EBV-driven B-cell immortalization. EBNA2 is expressed from the viral C promoter (Cp) and regulates its own expression by activating Cp through interaction with the cellular DNA binding protein CBF1. Through regulation of Cp and EBNA2 expression, EBV controls the pattern of latent protein expression and the type of latency established. To gain further insight into the important regulatory elements that modulate Cp usage, we isolated and sequenced the Cp regions corresponding to nucleotides 10251 to 11479 of the EBV genome (-1079 to +144 relative to the transcription initiation site) from the EBV-like lymphocryptoviruses found in baboons (herpesvirus papio; HVP) and Rhesus macaques (RhEBV). Sequence comparison of the approximately 1,230-bp Cp regions from these primate viruses revealed that EBV and HVP Cp sequences are 64% conserved, EBV and RhEBV Cp sequences are 66% conserved, and HVP and RhEBV Cp sequences are 65% conserved relative to each other. Approximately 50% of the residues are conserved among all three sequences, yet all three viruses have retained response elements for glucocorticoids, two positionally conserved CCAAT boxes, and positionally conserved TATA boxes. The putative EBNA2 100-bp enhancers within these promoters contain 54 conserved residues, and the binding sites for CBF1 and CBF2 are well conserved. Cp usage in the HVP- and RhEBV-transformed cell lines was detected by S1 nuclease protection analysis. Transient-transfection analysis showed that promoters of both HVP and RhEBV are responsive to EBNA2 and that they bind CBF1 and CBF2 in gel mobility shift assays. These results suggest that similar mechanisms for regulation of latent gene expression are conserved among the EBV-related lymphocryptoviruses found in nonhuman primates.

SNPs in Multi-Species Conserved Sequences (MCS as useful markers in association studies: a practical approach

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Pericak-Vance Margaret A

2007-08-01

Full Text Available Abstract Background Although genes play a key role in many complex diseases, the specific genes involved in most complex diseases remain largely unidentified. Their discovery will hinge on the identification of key sequence variants that are conclusively associated with disease. While much attention has been focused on variants in protein-coding DNA, variants in noncoding regions may also play many important roles in complex disease by altering gene regulation. Since the vast majority of noncoding genomic sequence is of unknown function, this increases the challenge of identifying "functional" variants that cause disease. However, evolutionary conservation can be used as a guide to indicate regions of noncoding or coding DNA that are likely to have biological function, and thus may be more likely to harbor SNP variants with functional consequences. To help bias marker selection in favor of such variants, we devised a process that prioritizes annotated SNPs for genotyping studies based on their location within Multi-species Conserved Sequences (MCSs and used this process to select SNPs in a region of linkage to a complex disease. This allowed us to evaluate the utility of the chosen SNPs for further association studies. Previously, a region of chromosome 1q43 was linked to Multiple Sclerosis (MS in a genome-wide screen. We chose annotated SNPs in the region based on location within MCSs (termed MCS-SNPs. We then obtained genotypes for 478 MCS-SNPs in 989 individuals from MS families. Results Analysis of our MCS-SNP genotypes from the 1q43 region and comparison to HapMap data confirmed that annotated SNPs in MCS regions are frequently polymorphic and show subtle signatures of selective pressure, consistent with previous reports of genome-wide variation in conserved regions. We also present an online tool that allows MCS data to be directly exported to the UCSC genome browser so that MCS-SNPs can be easily identified within genomic regions of

Conserved PCR primer set designing for closely-related species to complete mitochondrial genome sequencing using a sliding window-based PSO algorithm.

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Cheng-Hong Yang

Full Text Available BACKGROUND: Complete mitochondrial (mt genome sequencing is becoming increasingly common for phylogenetic reconstruction and as a model for genome evolution. For long template sequencing, i.e., like the entire mtDNA, it is essential to design primers for Polymerase Chain Reaction (PCR amplicons which are partly overlapping each other. The presented chromosome walking strategy provides the overlapping design to solve the problem for unreliable sequencing data at the 5' end and provides the effective sequencing. However, current algorithms and tools are mostly focused on the primer design for a local region in the genomic sequence. Accordingly, it is still challenging to provide the primer sets for the entire mtDNA. METHODOLOGY/PRINCIPAL FINDINGS: The purpose of this study is to develop an integrated primer design algorithm for entire mt genome in general, and for the common primer sets for closely-related species in particular. We introduce ClustalW to generate the multiple sequence alignment needed to find the conserved sequences in closely-related species. These conserved sequences are suitable for designing the common primers for the entire mtDNA. Using a heuristic algorithm particle swarm optimization (PSO, all the designed primers were computationally validated to fit the common primer design constraints, such as the melting temperature, primer length and GC content, PCR product length, secondary structure, specificity, and terminal limitation. The overlap requirement for PCR amplicons in the entire mtDNA is satisfied by defining the overlapping region with the sliding window technology. Finally, primer sets were designed within the overlapping region. The primer sets for the entire mtDNA sequences were successfully demonstrated in the example of two closely-related fish species. The pseudo code for the primer design algorithm is provided. CONCLUSIONS/SIGNIFICANCE: In conclusion, it can be said that our proposed sliding window-based PSO

Comparison of C. elegans and C. briggsae genome sequences reveals extensive conservation of chromosome organization and synteny.

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LaDeana W Hillier

2007-07-01

Full Text Available To determine whether the distinctive features of Caenorhabditis elegans chromosomal organization are shared with the C. briggsae genome, we constructed a single nucleotide polymorphism-based genetic map to order and orient the whole genome shotgun assembly along the six C. briggsae chromosomes. Although these species are of the same genus, their most recent common ancestor existed 80-110 million years ago, and thus they are more evolutionarily distant than, for example, human and mouse. We found that, like C. elegans chromosomes, C. briggsae chromosomes exhibit high levels of recombination on the arms along with higher repeat density, a higher fraction of intronic sequence, and a lower fraction of exonic sequence compared with chromosome centers. Despite extensive intrachromosomal rearrangements, 1:1 orthologs tend to remain in the same region of the chromosome, and colinear blocks of orthologs tend to be longer in chromosome centers compared with arms. More strikingly, the two species show an almost complete conservation of synteny, with 1:1 orthologs present on a single chromosome in one species also found on a single chromosome in the other. The conservation of both chromosomal organization and synteny between these two distantly related species suggests roles for chromosome organization in the fitness of an organism that are only poorly understood presently.

Determination of 5 '-leader sequences from radically disparate strains of porcine reproductive and respiratory syndrome virus reveals the presence of highly conserved sequence motifs

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Oleksiewicz, M.B.; Bøtner, Anette; Nielsen, Jens

1999-01-01

We determined the untranslated 5'-leader sequence for three different isolates of porcine reproductive and respiratory syndrome virus (PRRSV): pathogenic European- and American-types, as well as an American-type vaccine strain. 5'-leader from European- and American-type PRRSV differed in length...... (220 and 190 nt, respectively), and exhibited only approximately 50% nucleotide homology. Nevertheless, highly conserved areas were identified in the leader of all 3 PRRSV isolates, which constitute candidate motifs for binding of protein(s) involved in viral replication. These comparative data provide...

The interplay of sequence conservation and T cell immune recognition

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Bresciani, Anne Gøther; Sette, Alessandro; Greenbaum, Jason

2014-01-01

examined the hypothesis that conservation of a peptide in bacteria that are part of the healthy human microbiome leads to a reduced level of immunogenicity due to tolerization of T cells to the commensal bacteria. This was done by comparing experimentally characterized T cell epitope recognition data from...... the Immune Epitope Database with their conservation in the human microbiome. Indeed, we did see a lower immunogenicity for conserved peptides conserved. While many aspects how this conservation comparison is done require further optimization, this is a first step towards a better understanding T cell...... recognition of peptides in bacterial pathogens is influenced by their conservation in commensal bacteria. If the further work proves that this approach is successful, the degree of overlap of a peptide with the human proteome or microbiome could be added to the arsenal of tools available to assess peptide...

Domain architecture conservation in orthologs

Science.gov (United States)

2011-01-01

Background As orthologous proteins are expected to retain function more often than other homologs, they are often used for functional annotation transfer between species. However, ortholog identification methods do not take into account changes in domain architecture, which are likely to modify a protein's function. By domain architecture we refer to the sequential arrangement of domains along a protein sequence. To assess the level of domain architecture conservation among orthologs, we carried out a large-scale study of such events between human and 40 other species spanning the entire evolutionary range. We designed a score to measure domain architecture similarity and used it to analyze differences in domain architecture conservation between orthologs and paralogs relative to the conservation of primary sequence. We also statistically characterized the extents of different types of domain swapping events across pairs of orthologs and paralogs. Results The analysis shows that orthologs exhibit greater domain architecture conservation than paralogous homologs, even when differences in average sequence divergence are compensated for, for homologs that have diverged beyond a certain threshold. We interpret this as an indication of a stronger selective pressure on orthologs than paralogs to retain the domain architecture required for the proteins to perform a specific function. In general, orthologs as well as the closest paralogous homologs have very similar domain architectures, even at large evolutionary separation. The most common domain architecture changes observed in both ortholog and paralog pairs involved insertion/deletion of new domains, while domain shuffling and segment duplication/deletion were very infrequent. Conclusions On the whole, our results support the hypothesis that function conservation between orthologs demands higher domain architecture conservation than other types of homologs, relative to primary sequence conservation. This supports the

Position-specific prediction of methylation sites from sequence conservation based on information theory.

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Shi, Yinan; Guo, Yanzhi; Hu, Yayun; Li, Menglong

2015-07-23

Protein methylation plays vital roles in many biological processes and has been implicated in various human diseases. To fully understand the mechanisms underlying methylation for use in drug design and work in methylation-related diseases, an initial but crucial step is to identify methylation sites. The use of high-throughput bioinformatics methods has become imperative to predict methylation sites. In this study, we developed a novel method that is based only on sequence conservation to predict protein methylation sites. Conservation difference profiles between methylated and non-methylated peptides were constructed by the information entropy (IE) in a wider neighbor interval around the methylation sites that fully incorporated all of the environmental information. Then, the distinctive neighbor residues were identified by the importance scores of information gain (IG). The most representative model was constructed by support vector machine (SVM) for Arginine and Lysine methylation, respectively. This model yielded a promising result on both the benchmark dataset and independent test set. The model was used to screen the entire human proteome, and many unknown substrates were identified. These results indicate that our method can serve as a useful supplement to elucidate the mechanism of protein methylation and facilitate hypothesis-driven experimental design and validation.

Linkage disequilibrium of evolutionarily conserved regions in the human genome

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Johnson Todd A

2006-12-01

Full Text Available Abstract Background The strong linkage disequilibrium (LD recently found in genic or exonic regions of the human genome demonstrated that LD can be increased by evolutionary mechanisms that select for functionally important loci. This suggests that LD might be stronger in regions conserved among species than in non-conserved regions, since regions exposed to natural selection tend to be conserved. To assess this hypothesis, we used genome-wide polymorphism data from the HapMap project and investigated LD within DNA sequences conserved between the human and mouse genomes. Results Unexpectedly, we observed that LD was significantly weaker in conserved regions than in non-conserved regions. To investigate why, we examined sequence features that may distort the relationship between LD and conserved regions. We found that interspersed repeats, and not other sequence features, were associated with the weak LD tendency in conserved regions. To appropriately understand the relationship between LD and conserved regions, we removed the effect of repetitive elements and found that the high degree of sequence conservation was strongly associated with strong LD in coding regions but not with that in non-coding regions. Conclusion Our work demonstrates that the degree of sequence conservation does not simply increase LD as predicted by the hypothesis. Rather, it implies that purifying selection changes the polymorphic patterns of coding sequences but has little influence on the patterns of functional units such as regulatory elements present in non-coding regions, since the former are generally restricted by the constraint of maintaining a functional protein product across multiple exons while the latter may exist more as individually isolated units.

Human T-cell recognition of synthetic peptides representing conserved and variant sequences from the merozoite surface protein 2 of Plasmodium falciparum

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Theander, T G; Hviid, L; Dodoo, D

1997-01-01

Merozoite surface protein 2 (MSP2) is a malaria vaccine candidate currently undergoing clinical trials. We analyzed the peripheral blood mononuclear cell (PBMC) response to synthetic peptides corresponding to conserved and variant regions of the FCQ-27 allelic form of MSP2 in Ghanaian individuals....... The findings are encouraging for the development of a vaccine based on these T-epitope containing regions of MSP2, as the peptides were broadly recognized suggesting that they can bind to diverse HLA alleles and also because they include conserved MSP2 sequences. Immunisation with a vaccine construct...

Mapping the transcription start points of the Staphylococcus aureus eap, emp, and vwb promoters reveals a conserved octanucleotide sequence that is essential for expression of these genes.

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Harraghy, Niamh; Homerova, Dagmar; Herrmann, Mathias; Kormanec, Jan

2008-01-01

Mapping the transcription start points of the eap, emp, and vwb promoters revealed a conserved octanucleotide sequence (COS). Deleting this sequence abolished the expression of eap, emp, and vwb. However, electrophoretic mobility shift assays gave no evidence that this sequence was a binding site for SarA or SaeR, known regulators of eap and emp.

Spatially conserved regulatory elements identified within human and mouse Cd247 gene using high-throughput sequencing data from the ENCODE project

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Pundhir, Sachin; Hannibal, Tine Dahlbæk; Bang-Berthelsen, Claus Heiner

2014-01-01

. In this study, we have utilized the wealth of high-throughput sequencing data produced during the Encyclopedia of DNA Elements (ENCODE) project to identify spatially conserved regulatory elements within the Cd247 gene from human and mouse. We show the presence of two transcription factor binding sites...

Cytoplasmic protein binding to highly conserved sequences in the 3' untranslated region of mouse protamine 2 mRNA, a translationally regulated transcript of male germ cells

International Nuclear Information System (INIS)

Kwon, Y.K.; Hecht, N.B.

1991-01-01

The expression of the protamines, the predominant nuclear proteins of mammalian spermatozoa, is regulated translationally during male germ-cell development. The 3' untranslated region (UTR) of protamine 1 mRNA has been reported to control its time of translation. To understand the mechanisms controlling translation of the protamine mRNAs, we have sought to identify cis elements of the 3' UTR of protamine 2 mRNA that are recognized by cytoplasmic factors. From gel retardation assays, two sequence elements are shown to form specific RNA-protein complexes. Protein binding sites of the two complexes were determined by RNase T1 mapping, by blocking the putative binding sites with antisense oligonucleotides, and by competition assays. The sequences of these elements, located between nucleotides + 537 and + 572 in protamine 2 mRNA, are highly conserved among postmeiotic translationally regulated nuclear proteins of the mammalian testis. Two closely linked protein binding sites were detected. UV-crosslinking studies revealed that a protein of about 18 kDa binds to one of the conserved sequences. These data demonstrate specific protein binding to a highly conserved 3' UTR of translationally regulated testicular mRNA

BlockLogo: Visualization of peptide and sequence motif conservation

DEFF Research Database (Denmark)

Olsen, Lars Rønn; Kudahl, Ulrich Johan; Simon, Christian

2013-01-01

BlockLogo is a web-server application for the visualization of protein and nucleotide fragments, continuous protein sequence motifs, and discontinuous sequence motifs using calculation of block entropy from multiple sequence alignments. The user input consists of a multiple sequence alignment, se...

The effects of sequence and type of chemotherapy and radiation therapy on cosmesis and complications after breast conservation therapy

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Markiewicz, Deborah A.; Schultz, Delray J.; Haas, Jonathan A.; Harris, Eleanor E. R.; Fox, Kevin R.; Glick, John H.; Solin, Lawrence J.

1996-01-01

Purpose: Chemotherapy plays an increasingly important role in the treatment of both node-negative and node-positive breast cancer patients, but the optimal sequencing of chemotherapy and radiation therapy is not well established. The purpose of this study is to evaluate the interaction of sequence and type of chemotherapy and hormonal therapy given with radiation therapy on the cosmetic outcome and the incidence of complications of Stage I and II breast cancer patients treated with breast-conserving therapy. Methods and Materials: The records of 1053 Stage I and II breast cancer patients treated with curative intent with breast-conserving surgery, axillary dissection, and radiation therapy between 1977-1991 were reviewed. Median follow-up after treatment was 6.7 years. Two hundred fourteen patients received chemotherapy alone, 141 patients received hormonal therapy alone, 86 patients received both, and 612 patients received no adjuvant therapy. Patients who received chemotherapy ± hormonal therapy were grouped according to sequence of chemotherapy: (a) concurrent = concurrent chemotherapy with radiation therapy followed by chemotherapy; (b) sequential = radiation followed by chemotherapy or chemotherapy followed by radiation; and (c) sandwich = chemotherapy followed by concurrent chemotherapy and radiation followed by chemotherapy. Compared to node negative patients, node-positive patients more commonly received chemotherapy (77 vs. 9%, p < 0.0001) and/or hormonal therapy (40 vs. 14%, p < 0.0001). Among patients who received chemotherapy, the majority (243 patients) received concurrent chemotherapy and radiation therapy with two cycles of cytoxan and 5-fluorouracil (5-FU) administered during radiation followed by six cycles of chemotherapy with cytoxan, 5-fluorouracil and either methotrexate(CMF) or doxorubicin(CAF). For analysis of cosmesis, patients included were relapse free with 3 years minimum follow-up. Results: The use of chemotherapy had an adverse effect

Sequence conservation between porcine and human LRRK2

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Larsen, Knud; Madsen, Lone Bruhn

2009-01-01

 Leucine-rich repeat kinase 2 (LRRK2) is a member of the ROCO protein superfamily (Ras of complex proteins (Roc) with a C-terminal Roc domain). Mutations in the LRRK2 gene lead to autosomal dominant Parkinsonism. We have cloned the porcine LRRK2 cDNA in an attempt to characterize conserved...... and expression patterns are conserved across species. The porcine LRRK2 gene was mapped to chromosome 5q25. The results obtained suggest that the LRRK2 gene might be of particular interest in our attempt to generate a transgenic porcine model for Parkinson's disease...

Conservation and variability of dengue virus proteins: implications for vaccine design.

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Asif M Khan

2008-08-01

Full Text Available Genetic variation and rapid evolution are hallmarks of RNA viruses, the result of high mutation rates in RNA replication and selection of mutants that enhance viral adaptation, including the escape from host immune responses. Variability is uneven across the genome because mutations resulting in a deleterious effect on viral fitness are restricted. RNA viruses are thus marked by protein sites permissive to multiple mutations and sites critical to viral structure-function that are evolutionarily robust and highly conserved. Identification and characterization of the historical dynamics of the conserved sites have relevance to multiple applications, including potential targets for diagnosis, and prophylactic and therapeutic purposes.We describe a large-scale identification and analysis of evolutionarily highly conserved amino acid sequences of the entire dengue virus (DENV proteome, with a focus on sequences of 9 amino acids or more, and thus immune-relevant as potential T-cell determinants. DENV protein sequence data were collected from the NCBI Entrez protein database in 2005 (9,512 sequences and again in 2007 (12,404 sequences. Forty-four (44 sequences (pan-DENV sequences, mainly those of nonstructural proteins and representing approximately 15% of the DENV polyprotein length, were identical in 80% or more of all recorded DENV sequences. Of these 44 sequences, 34 ( approximately 77% were present in >or=95% of sequences of each DENV type, and 27 ( approximately 61% were conserved in other Flaviviruses. The frequencies of variants of the pan-DENV sequences were low (0 to approximately 5%, as compared to variant frequencies of approximately 60 to approximately 85% in the non pan-DENV sequence regions. We further showed that the majority of the conserved sequences were immunologically relevant: 34 contained numerous predicted human leukocyte antigen (HLA supertype-restricted peptide sequences, and 26 contained T-cell determinants identified by

Comparative transcriptome analysis within the Lolium/Festuca species complex reveals high sequence conservation

DEFF Research Database (Denmark)

Czaban, Adrian; Sharma, Sapna; Byrne, Stephen

2015-01-01

species from the Lolium-Festuca complex, ranging from 52,166 to 72,133 transcripts per assembly. We have also predicted a set of proteins and validated it with a high-confidence protein database from three closely related species (H. vulgare, B. distachyon and O. sativa). We have obtained gene family...... clusters for the four species using OrthoMCL and analyzed their inferred phylogenetic relationships. Our results indicate that VRN2 is a candidate gene for differentiating vernalization and non-vernalization types in the Lolium-Festuca complex. Grouping of the gene families based on their BLAST identity...... enabled us to divide ortholog groups into those that are very conserved and those that are more evolutionarily relaxed. The ratio of the non-synonumous to synonymous substitutions enabled us to pinpoint protein sequences evolving in response to positive selection. These proteins may explain some...

An effective approach for annotation of protein families with low sequence similarity and conserved motifs: identifying GDSL hydrolases across the plant kingdom.

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Vujaklija, Ivan; Bielen, Ana; Paradžik, Tina; Biđin, Siniša; Goldstein, Pavle; Vujaklija, Dušica

2016-02-18

The massive accumulation of protein sequences arising from the rapid development of high-throughput sequencing, coupled with automatic annotation, results in high levels of incorrect annotations. In this study, we describe an approach to decrease annotation errors of protein families characterized by low overall sequence similarity. The GDSL lipolytic family comprises proteins with multifunctional properties and high potential for pharmaceutical and industrial applications. The number of proteins assigned to this family has increased rapidly over the last few years. In particular, the natural abundance of GDSL enzymes reported recently in plants indicates that they could be a good source of novel GDSL enzymes. We noticed that a significant proportion of annotated sequences lack specific GDSL motif(s) or catalytic residue(s). Here, we applied motif-based sequence analyses to identify enzymes possessing conserved GDSL motifs in selected proteomes across the plant kingdom. Motif-based HMM scanning (Viterbi decoding-VD and posterior decoding-PD) and the here described PD/VD protocol were successfully applied on 12 selected plant proteomes to identify sequences with GDSL motifs. A significant number of identified GDSL sequences were novel. Moreover, our scanning approach successfully detected protein sequences lacking at least one of the essential motifs (171/820) annotated by Pfam profile search (PfamA) as GDSL. Based on these analyses we provide a curated list of GDSL enzymes from the selected plants. CLANS clustering and phylogenetic analysis helped us to gain a better insight into the evolutionary relationship of all identified GDSL sequences. Three novel GDSL subfamilies as well as unreported variations in GDSL motifs were discovered in this study. In addition, analyses of selected proteomes showed a remarkable expansion of GDSL enzymes in the lycophyte, Selaginella moellendorffii. Finally, we provide a general motif-HMM scanner which is easily accessible through

Genome Analysis of Conserved Dehydrin Motifs in Vascular Plants

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Ahmad A. Malik

2017-05-01

Full Text Available Dehydrins, a large family of abiotic stress proteins, are defined by the presence of a mostly conserved motif known as the K-segment, and may also contain two other conserved motifs known as the Y-segment and S-segment. Using the dehydrin literature, we developed a sequence motif definition of the K-segment, which we used to create a large dataset of dehydrin sequences by searching the Pfam00257 dehydrin dataset and the Phytozome 10 sequences of vascular plants. A comprehensive analysis of these sequences reveals that lysine residues are highly conserved in the K-segment, while the amino acid type is often conserved at other positions. Despite the Y-segment name, the central tyrosine is somewhat conserved, but can be substituted with two other small aromatic amino acids (phenylalanine or histidine. The S-segment contains a series of serine residues, but in some proteins is also preceded by a conserved LHR sequence. In many dehydrins containing all three of these motifs the S-segment is linked to the K-segment by a GXGGRRKK motif (where X can be any amino acid, suggesting a functional linkage between these two motifs. An analysis of the sequences shows that the dehydrin architecture and several biochemical properties (isoelectric point, molecular mass, and hydrophobicity score are dependent on each other, and that some dehydrin architectures are overexpressed during certain abiotic stress, suggesting that they may be optimized for a specific abiotic stress while others are involved in all forms of dehydration stress (drought, cold, and salinity.

Evolutionary conservation of regulatory elements in vertebrate HOX gene clusters

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Santini, Simona; Boore, Jeffrey L.; Meyer, Axel

2003-12-31

Due to their high degree of conservation, comparisons of DNA sequences among evolutionarily distantly-related genomes permit to identify functional regions in noncoding DNA. Hox genes are optimal candidate sequences for comparative genome analyses, because they are extremely conserved in vertebrates and occur in clusters. We aligned (Pipmaker) the nucleotide sequences of HoxA clusters of tilapia, pufferfish, striped bass, zebrafish, horn shark, human and mouse (over 500 million years of evolutionary distance). We identified several highly conserved intergenic sequences, likely to be important in gene regulation. Only a few of these putative regulatory elements have been previously described as being involved in the regulation of Hox genes, while several others are new elements that might have regulatory functions. The majority of these newly identified putative regulatory elements contain short fragments that are almost completely conserved and are identical to known binding sites for regulatory proteins (Transfac). The conserved intergenic regions located between the most rostrally expressed genes in the developing embryo are longer and better retained through evolution. We document that presumed regulatory sequences are retained differentially in either A or A clusters resulting from a genome duplication in the fish lineage. This observation supports both the hypothesis that the conserved elements are involved in gene regulation and the Duplication-Deletion-Complementation model.

Molecular dissection of a contiguous gene syndrome: Frequent submicroscopic deletions, evolutionarily conserved sequences, and a hypomethylated island in the Miller-Dieker chromosome region

International Nuclear Information System (INIS)

Ledbetter, D.H.; Ledbetter, S.A.; vanTuinen, P.

1989-01-01

The Miller-Dieker syndrome (MDS), composed of characteristic facial abnormalities and a severe neuronal migration disorder affecting the cerebral cortex, is caused by visible or submicroscopic deletions of chromosome band 17p13. Twelve anonymous DNA markers were tested against a panel of somatic cell hybrids containing 17p deletions from seven MDS patients. All patients, including three with normal karyotypes, are deleted for a variable set of 5-12 markers. Two highly polymorphic VNTR (variable number of tandem repeats) probes, YNZ22 and YNH37, are codeleted in all patients tested and make molecular diagnosis for this disorder feasible. By pulsed-field gel electrophoresis, YNZ22 and YNH37 were shown to be within 30 kilobases (kb) of each other. Cosmid clones containing both VNTR sequences were identified, and restriction mapping showed them to be 100 kb were completely deleted in all patients, providing a minimum estimate of the size of the MDS critical region. A hypomethylated island and evolutionarily conserved sequences were identified within this 100-kb region, indications of the presence of one or more expressed sequences potentially involved in the pathophysiology of this disorder. The conserved sequences were mapped to mouse chromosome 11 by using mouse-rat somatic cell hybrids, extending the remarkable homology between human chromosome 17 and mouse chromosome 11 by 30 centimorgans, into the 17p telomere region

Human developmental enhancers conserved between deuterostomes and protostomes.

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Shoa L Clarke

Full Text Available The identification of homologies, whether morphological, molecular, or genetic, is fundamental to our understanding of common biological principles. Homologies bridging the great divide between deuterostomes and protostomes have served as the basis for current models of animal evolution and development. It is now appreciated that these two clades share a common developmental toolkit consisting of conserved transcription factors and signaling pathways. These patterning genes sometimes show common expression patterns and genetic interactions, suggesting the existence of similar or even conserved regulatory apparatus. However, previous studies have found no regulatory sequence conserved between deuterostomes and protostomes. Here we describe the first such enhancers, which we call bilaterian conserved regulatory elements (Bicores. Bicores show conservation of sequence and gene synteny. Sequence conservation of Bicores reflects conserved patterns of transcription factor binding sites. We predict that Bicores act as response elements to signaling pathways, and we show that Bicores are developmental enhancers that drive expression of transcriptional repressors in the vertebrate central nervous system. Although the small number of identified Bicores suggests extensive rewiring of cis-regulation between the protostome and deuterostome clades, additional Bicores may be revealed as our understanding of cis-regulatory logic and sample of bilaterian genomes continue to grow.

Further results on universal properties in conservative dynamical systems

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Benettin, G [Padua Univ. (Italy). Ist. di Fisica; Galgani, L; Giorgilli, A [Milan Univ. (Italy). Ist. di Fisica; Milan Univ. (Italy). Ist. di Matematica)

1980-10-11

In conservative dynamical systems depending on a parameter, sequences of period-doubling bifurcations can be observed by varying the parameter, starting from a stable fixed point. These sequences are analogous to those already known for dissipative systems. The paper shows some new results obtained for two-dimensional conservative mappings.

The First Myriapod Genome Sequence Reveals Conservative Arthropod Gene Content and Genome Organisation in the Centipede Strigamia maritima

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Chipman, Ariel D.; Ferrier, David E. K.; Brena, Carlo; Qu, Jiaxin; Hughes, Daniel S. T.; Schröder, Reinhard; Torres-Oliva, Montserrat; Znassi, Nadia; Jiang, Huaiyang; Almeida, Francisca C.; Alonso, Claudio R.; Apostolou, Zivkos; Aqrawi, Peshtewani; Arthur, Wallace; Barna, Jennifer C. J.; Blankenburg, Kerstin P.; Brites, Daniela; Capella-Gutiérrez, Salvador; Coyle, Marcus; Dearden, Peter K.; Du Pasquier, Louis; Duncan, Elizabeth J.; Ebert, Dieter; Eibner, Cornelius; Erikson, Galina; Evans, Peter D.; Extavour, Cassandra G.; Francisco, Liezl; Gabaldón, Toni; Gillis, William J.; Goodwin-Horn, Elizabeth A.; Green, Jack E.; Griffiths-Jones, Sam; Grimmelikhuijzen, Cornelis J. P.; Gubbala, Sai; Guigó, Roderic; Han, Yi; Hauser, Frank; Havlak, Paul; Hayden, Luke; Helbing, Sophie; Holder, Michael; Hui, Jerome H. L.; Hunn, Julia P.; Hunnekuhl, Vera S.; Jackson, LaRonda; Javaid, Mehwish; Jhangiani, Shalini N.; Jiggins, Francis M.; Jones, Tamsin E.; Kaiser, Tobias S.; Kalra, Divya; Kenny, Nathan J.; Korchina, Viktoriya; Kovar, Christie L.; Kraus, F. Bernhard; Lapraz, François; Lee, Sandra L.; Lv, Jie; Mandapat, Christigale; Manning, Gerard; Mariotti, Marco; Mata, Robert; Mathew, Tittu; Neumann, Tobias; Newsham, Irene; Ngo, Dinh N.; Ninova, Maria; Okwuonu, Geoffrey; Ongeri, Fiona; Palmer, William J.; Patil, Shobha; Patraquim, Pedro; Pham, Christopher; Pu, Ling-Ling; Putman, Nicholas H.; Rabouille, Catherine; Ramos, Olivia Mendivil; Rhodes, Adelaide C.; Robertson, Helen E.; Robertson, Hugh M.; Ronshaugen, Matthew; Rozas, Julio; Saada, Nehad; Sánchez-Gracia, Alejandro; Scherer, Steven E.; Schurko, Andrew M.; Siggens, Kenneth W.; Simmons, DeNard; Stief, Anna; Stolle, Eckart; Telford, Maximilian J.; Tessmar-Raible, Kristin; Thornton, Rebecca; van der Zee, Maurijn; von Haeseler, Arndt; Williams, James M.; Willis, Judith H.; Wu, Yuanqing; Zou, Xiaoyan; Lawson, Daniel; Muzny, Donna M.; Worley, Kim C.; Gibbs, Richard A.; Akam, Michael; Richards, Stephen

2014-01-01

Myriapods (e.g., centipedes and millipedes) display a simple homonomous body plan relative to other arthropods. All members of the class are terrestrial, but they attained terrestriality independently of insects. Myriapoda is the only arthropod class not represented by a sequenced genome. We present an analysis of the genome of the centipede Strigamia maritima. It retains a compact genome that has undergone less gene loss and shuffling than previously sequenced arthropods, and many orthologues of genes conserved from the bilaterian ancestor that have been lost in insects. Our analysis locates many genes in conserved macro-synteny contexts, and many small-scale examples of gene clustering. We describe several examples where S. maritima shows different solutions from insects to similar problems. The insect olfactory receptor gene family is absent from S. maritima, and olfaction in air is likely effected by expansion of other receptor gene families. For some genes S. maritima has evolved paralogues to generate coding sequence diversity, where insects use alternate splicing. This is most striking for the Dscam gene, which in Drosophila generates more than 100,000 alternate splice forms, but in S. maritima is encoded by over 100 paralogues. We see an intriguing linkage between the absence of any known photosensory proteins in a blind organism and the additional absence of canonical circadian clock genes. The phylogenetic position of myriapods allows us to identify where in arthropod phylogeny several particular molecular mechanisms and traits emerged. For example, we conclude that juvenile hormone signalling evolved with the emergence of the exoskeleton in the arthropods and that RR-1 containing cuticle proteins evolved in the lineage leading to Mandibulata. We also identify when various gene expansions and losses occurred. The genome of S. maritima offers us a unique glimpse into the ancestral arthropod genome, while also displaying many adaptations to its specific

Strong minor groove base conservation in sequence logos implies DNA distortion or base flipping during replication and transcription initiation | Center for Cancer Research

Science.gov (United States)

Dubbed "Tom's T" by Dhruba Chattoraj, the unusually conserved thymine at position +7 in bacteriophage P1 plasmid RepA DNA binding sites rises above repressor and acceptor sequence logos. The T appears to represent base flipping prior to helix opening in this DNA replication initation protein.

Short sequence motifs, overrepresented in mammalian conservednon-coding sequences

Energy Technology Data Exchange (ETDEWEB)

Minovitsky, Simon; Stegmaier, Philip; Kel, Alexander; Kondrashov,Alexey S.; Dubchak, Inna

2007-02-21

Background: A substantial fraction of non-coding DNAsequences of multicellular eukaryotes is under selective constraint. Inparticular, ~;5 percent of the human genome consists of conservednon-coding sequences (CNSs). CNSs differ from other genomic sequences intheir nucleotide composition and must play important functional roles,which mostly remain obscure.Results: We investigated relative abundancesof short sequence motifs in all human CNSs present in the human/mousewhole-genome alignments vs. three background sets of sequences: (i)weakly conserved or unconserved non-coding sequences (non-CNSs); (ii)near-promoter sequences (located between nucleotides -500 and -1500,relative to a start of transcription); and (iii) random sequences withthe same nucleotide composition as that of CNSs. When compared tonon-CNSs and near-promoter sequences, CNSs possess an excess of AT-richmotifs, often containing runs of identical nucleotides. In contrast, whencompared to random sequences, CNSs contain an excess of GC-rich motifswhich, however, lack CpG dinucleotides. Thus, abundance of short sequencemotifs in human CNSs, taken as a whole, is mostly determined by theiroverall compositional properties and not by overrepresentation of anyspecific short motifs. These properties are: (i) high AT-content of CNSs,(ii) a tendency, probably due to context-dependent mutation, of A's andT's to clump, (iii) presence of short GC-rich regions, and (iv) avoidanceof CpG contexts, due to their hypermutability. Only a small number ofshort motifs, overrepresented in all human CNSs are similar to bindingsites of transcription factors from the FOX family.Conclusion: Human CNSsas a whole appear to be too broad a class of sequences to possess strongfootprints of any short sequence-specific functions. Such footprintsshould be studied at the level of functional subclasses of CNSs, such asthose which flank genes with a particular pattern of expression. Overallproperties of CNSs are affected by

Highly conserved non-coding elements on either side of SOX9 associated with Pierre Robin sequence.

Science.gov (United States)

Benko, Sabina; Fantes, Judy A; Amiel, Jeanne; Kleinjan, Dirk-Jan; Thomas, Sophie; Ramsay, Jacqueline; Jamshidi, Negar; Essafi, Abdelkader; Heaney, Simon; Gordon, Christopher T; McBride, David; Golzio, Christelle; Fisher, Malcolm; Perry, Paul; Abadie, Véronique; Ayuso, Carmen; Holder-Espinasse, Muriel; Kilpatrick, Nicky; Lees, Melissa M; Picard, Arnaud; Temple, I Karen; Thomas, Paul; Vazquez, Marie-Paule; Vekemans, Michel; Roest Crollius, Hugues; Hastie, Nicholas D; Munnich, Arnold; Etchevers, Heather C; Pelet, Anna; Farlie, Peter G; Fitzpatrick, David R; Lyonnet, Stanislas

2009-03-01

Pierre Robin sequence (PRS) is an important subgroup of cleft palate. We report several lines of evidence for the existence of a 17q24 locus underlying PRS, including linkage analysis results, a clustering of translocation breakpoints 1.06-1.23 Mb upstream of SOX9, and microdeletions both approximately 1.5 Mb centromeric and approximately 1.5 Mb telomeric of SOX9. We have also identified a heterozygous point mutation in an evolutionarily conserved region of DNA with in vitro and in vivo features of a developmental enhancer. This enhancer is centromeric to the breakpoint cluster and maps within one of the microdeletion regions. The mutation abrogates the in vitro enhancer function and alters binding of the transcription factor MSX1 as compared to the wild-type sequence. In the developing mouse mandible, the 3-Mb region bounded by the microdeletions shows a regionally specific chromatin decompaction in cells expressing Sox9. Some cases of PRS may thus result from developmental misexpression of SOX9 due to disruption of very-long-range cis-regulatory elements.

Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium.

Science.gov (United States)

Catania, Francesco; Lynch, Michael

2010-05-04

In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa) remains a virtually unexplored issue. By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Our observations 1) shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2) are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3) reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes.

CodonLogo: a sequence logo-based viewer for codon patterns.

Science.gov (United States)

Sharma, Virag; Murphy, David P; Provan, Gregory; Baranov, Pavel V

2012-07-15

Conserved patterns across a multiple sequence alignment can be visualized by generating sequence logos. Sequence logos show each column in the alignment as stacks of symbol(s) where the height of a stack is proportional to its informational content, whereas the height of each symbol within the stack is proportional to its frequency in the column. Sequence logos use symbols of either nucleotide or amino acid alphabets. However, certain regulatory signals in messenger RNA (mRNA) act as combinations of codons. Yet no tool is available for visualization of conserved codon patterns. We present the first application which allows visualization of conserved regions in a multiple sequence alignment in the context of codons. CodonLogo is based on WebLogo3 and uses the same heuristics but treats codons as inseparable units of a 64-letter alphabet. CodonLogo can discriminate patterns of codon conservation from patterns of nucleotide conservation that appear indistinguishable in standard sequence logos. The CodonLogo source code and its implementation (in a local version of the Galaxy Browser) are available at http://recode.ucc.ie/CodonLogo and through the Galaxy Tool Shed at http://toolshed.g2.bx.psu.edu/.

Conservation of HIV-1 T cell epitopes across time and clades

DEFF Research Database (Denmark)

Levitz, Lauren; Koita, Ousmane A; Sangare, Kotou

2012-01-01

HIV genomic sequence variability has complicated efforts to generate an effective globally relevant vaccine. Regions of the viral genome conserved in sequence and across time may represent the "Achilles' heel" of HIV. In this study, highly conserved T-cell epitopes were selected using immunoinfor...

CONREAL web server: identification and visualization of conserved transcription factor binding sites

NARCIS (Netherlands)

Berezikov, E.; Guryev, V.; Cuppen, E.

2005-01-01

The use of orthologous sequences and phylogenetic footprinting approaches have become popular for the recognition of conserved and potentially functional sequences. Several algorithms have been developed for the identification of conserved transcription factor binding sites (TFBSs), which are

cDNA cloning and sequencing of human fibrillarin, a conserved nucleolar protein recognized by autoimmune antisera

International Nuclear Information System (INIS)

Aris, J.P.; Blobel, G.

1991-01-01

The authors have isolated a 1.1-kilobase cDNA clone that encodes human fibrillarin by screening a hepatoma library in parallel with DNA probes derived from the fibrillarin genes of Saccharomyces cerevisiae (NOP1) and Xenopus laevis. RNA blot analysis indicates that the corresponding mRNA is ∼1,300 nucleotides in length. Human fibrillarin expressed in vitro migrates on SDS gels as a 36-kDa protein that is specifically immunoprecipitated by antisera from humans with scleroderma autoimmune disease. Human fibrillarin contains an amino-terminal repetitive domain ∼75-80 amino acids in length that is rich in glycine and arginine residues and is similar to amino-terminal domains in the yeast and Xenopus fibrillarins. The occurrence of a putative RNA-binding domain and an RNP consensus sequence within the protein is consistent with the association of fibrillarin with small nucleolar RNAs. Protein sequence alignments show that 67% of amino acids from human fibrillarin are identical to those in yeast fibrillarin and that 81% are identical to those in Xenopus fibrillarin. This identity suggests the evolutionary conservation of an important function early in the pathway for ribosome biosynthesis

Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium

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Lynch Michael

2010-05-01

Full Text Available Abstract Background In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa remains a virtually unexplored issue. Results By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Conclusions Our observations 1 shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2 are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3 reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes.

Close Sequence Comparisons are Sufficient to Identify Humancis-Regulatory Elements

Energy Technology Data Exchange (ETDEWEB)

Prabhakar, Shyam; Poulin, Francis; Shoukry, Malak; Afzal, Veena; Rubin, Edward M.; Couronne, Olivier; Pennacchio, Len A.

2005-12-01

Cross-species DNA sequence comparison is the primary method used to identify functional noncoding elements in human and other large genomes. However, little is known about the relative merits of evolutionarily close and distant sequence comparisons, due to the lack of a universal metric for sequence conservation, and also the paucity of empirically defined benchmark sets of cis-regulatory elements. To address this problem, we developed a general-purpose algorithm (Gumby) that detects slowly-evolving regions in primate, mammalian and more distant comparisons without requiring adjustment of parameters, and ranks conserved elements by P-value using Karlin-Altschul statistics. We benchmarked Gumby predictions against previously identified cis-regulatory elements at diverse genomic loci, and also tested numerous extremely conserved human-rodent sequences for transcriptional enhancer activity using reporter-gene assays in transgenic mice. Human regulatory elements were identified with acceptable sensitivity and specificity by comparison with 1-5 other eutherian mammals or 6 other simian primates. More distant comparisons (marsupial, avian, amphibian and fish) failed to identify many of the empirically defined functional noncoding elements. We derived an intuitive relationship between ancient and recent noncoding sequence conservation from whole genome comparative analysis, which explains some of these findings. Lastly, we determined that, in addition to strength of conservation, genomic location and/or density of surrounding conserved elements must also be considered in selecting candidate enhancers for testing at embryonic time points.

Conserved hypothetical protein Rv1977 in Mycobacterium tuberculosis strains contains sequence polymorphisms and might be involved in ongoing immune evasion.

Science.gov (United States)

Jiang, Yi; Liu, Haican; Wang, Xuezhi; Li, Guilian; Qiu, Yan; Dou, Xiangfeng; Wan, Kanglin

2015-01-01

Host immune pressure and associated parasite immune evasion are key features of host-pathogen co-evolution. A previous study showed that human T cell epitopes of Mycobacterium tuberculosis are evolutionarily hyperconserved and thus it was deduced that M. tuberculosis lacks antigenic variation and immune evasion. Here, we selected 151 clinical Mycobacterium tuberculosis isolates from China, amplified gene encoding Rv1977 and compared the sequences. The results showed that Rv1977, a conserved hypothetical protein, is not conserved in M. tuberculosis strains and there are polymorphisms existed in the protein. Some mutations, especially one frameshift mutation, occurred in the antigen Rv1977, which is uncommon in M.tb strains and may lead to the protein function altering. Mutations and deletion in the gene all affect one of three T cell epitopes and the changed T cell epitope contained more than one variable position, which may suggest ongoing immune evasion.

Lanthanum-Based Metal-Organic Frameworks for Specific Detection of Sudan Virus RNA Conservative Sequences down to Single-Base Mismatch.

Science.gov (United States)

Yang, Shui-Ping; Zhao, Wei; Hu, Pei-Pei; Wu, Ke-Yang; Jiang, Zhi-Hong; Bai, Li-Ping; Li, Min-Min; Chen, Jin-Xiang

2017-12-18

Reactions of La(NO 3 ) 3 ·6H 2 O with the polar, tritopic quaternized carboxylate ligands N-carboxymethyl-3,5-dicarboxylpyridinium bromide (H 3 CmdcpBr) and N-(4-carboxybenzyl)-3,5-dicarboxylpyridinium bromide (H 3 CbdcpBr) afford two water-stable metal-organic frameworks (MOFs) of {[La 4 (Cmdcp) 6 (H 2 O) 9 ]} n (1, 3D) and {[La 2 (Cbdcp) 3 (H 2 O) 10 ]} n (2, 2D). MOFs 1 and 2 absorb the carboxyfluorescein (FAM)-tagged probe DNA (P-DNA) and quench the fluorescence of FAM via a photoinduced electron transfer (PET) process. The nonemissive P-DNA@MOF hybrids thus formed in turn function as sensing platforms to distinguish conservative linear, single-stranded RNA sequences of Sudan virus with high selectivity and low detection limits of 112 and 67 pM, respectively (at a signal-to-noise ratio of 3). These hybrids also exhibit high specificity and discriminate down to single-base mismatch RNA sequences.

Comparative anatomy of the human APRT gene and enzyme: nucleotide sequence divergence and conservation of a nonrandom CpG dinucleotide arrangement

International Nuclear Information System (INIS)

Broderick, T.P.; Schaff, D.A.; Bertino, A.M.; Dush, M.K.; Tischfield, J.A.; Stambrook, P.J.

1987-01-01

The functional human adenine phosphoribosyltransferase (APRT) gene is <2.6 kilobases in length and contains five exons. The amino acid sequences of APRTs have been highly conserved throughout evolution. The human enzyme is 82%, 90%, and 40% identical to the mouse, hamster, and Escherichia coli enzymes, respectively. The promoter region of the human APRT gene, like that of several other housekeeping genes, lacks TATA and CCAAT boxes but contains five GC boxes that are potential binding sites for the Sp1 transcription factor. The distal three, however, are dispensable for gene expression. Comparison between human and mouse APRT gene nucleotide sequences reveals a high degree of homology within protein coding regions but an absence of significant homology in 5' flanking, 3' untranslated, and intron sequences, except for similarly positioned GC boxes in the promoter region and a 26-base-pair region in intron 3. This 26-base-pair sequence is 92% identical with a similarly positioned sequence in the mouse gene and is also found in intron 3 of the hamster gene, suggesting that its retention may be a consequence of stringent selection. The positions of all introns have been precisely retained in the human and both rodent genes. Retention of an elevated CpG dinucleotide content, despite loss of sequence homology, suggests that there may be selection for CpG dinucleotides in these regions and that their maintenance may be important for APRT gene function

The highly conserved codon following the slippery sequence supports -1 frameshift efficiency at the HIV-1 frameshift site.

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Suneeth F Mathew

Full Text Available HIV-1 utilises -1 programmed ribosomal frameshifting to translate structural and enzymatic domains in a defined proportion required for replication. A slippery sequence, U UUU UUA, and a stem-loop are well-defined RNA features modulating -1 frameshifting in HIV-1. The GGG glycine codon immediately following the slippery sequence (the 'intercodon' contributes structurally to the start of the stem-loop but has no defined role in current models of the frameshift mechanism, as slippage is inferred to occur before the intercodon has reached the ribosomal decoding site. This GGG codon is highly conserved in natural isolates of HIV. When the natural intercodon was replaced with a stop codon two different decoding molecules-eRF1 protein or a cognate suppressor tRNA-were able to access and decode the intercodon prior to -1 frameshifting. This implies significant slippage occurs when the intercodon is in the (perhaps distorted ribosomal A site. We accommodate the influence of the intercodon in a model of frame maintenance versus frameshifting in HIV-1.

Violation of an evolutionarily conserved immunoglobulin diversity gene sequence preference promotes production of dsDNA-specific IgG antibodies.

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Aaron Silva-Sanchez

Full Text Available Variability in the developing antibody repertoire is focused on the third complementarity determining region of the H chain (CDR-H3, which lies at the center of the antigen binding site where it often plays a decisive role in antigen binding. The power of VDJ recombination and N nucleotide addition has led to the common conception that the sequence of CDR-H3 is unrestricted in its variability and random in its composition. Under this view, the immune response is solely controlled by somatic positive and negative clonal selection mechanisms that act on individual B cells to promote production of protective antibodies and prevent the production of self-reactive antibodies. This concept of a repertoire of random antigen binding sites is inconsistent with the observation that diversity (DH gene segment sequence content by reading frame (RF is evolutionarily conserved, creating biases in the prevalence and distribution of individual amino acids in CDR-H3. For example, arginine, which is often found in the CDR-H3 of dsDNA binding autoantibodies, is under-represented in the commonly used DH RFs rearranged by deletion, but is a frequent component of rarely used inverted RF1 (iRF1, which is rearranged by inversion. To determine the effect of altering this germline bias in DH gene segment sequence on autoantibody production, we generated mice that by genetic manipulation are forced to utilize an iRF1 sequence encoding two arginines. Over a one year period we collected serial serum samples from these unimmunized, specific pathogen-free mice and found that more than one-fifth of them contained elevated levels of dsDNA-binding IgG, but not IgM; whereas mice with a wild type DH sequence did not. Thus, germline bias against the use of arginine enriched DH sequence helps to reduce the likelihood of producing self-reactive antibodies.

High-Throughput Sequencing Reveals Diverse Sets of Conserved, Nonconserved, and Species-Specific miRNAs in Jute

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Md. Tariqul Islam

2015-01-01

Full Text Available MicroRNAs play a pivotal role in regulating a broad range of biological processes, acting by cleaving mRNAs or by translational repression. A group of plant microRNAs are evolutionarily conserved; however, others are expressed in a species-specific manner. Jute is an agroeconomically important fibre crop; nonetheless, no practical information is available for microRNAs in jute to date. In this study, Illumina sequencing revealed a total of 227 known microRNAs and 17 potential novel microRNA candidates in jute, of which 164 belong to 23 conserved families and the remaining 63 belong to 58 nonconserved families. Among a total of 81 identified microRNA families, 116 potential target genes were predicted for 39 families and 11 targets were predicted for 4 among the 17 identified novel microRNAs. For understanding better the functions of microRNAs, target genes were analyzed by Gene Ontology and their pathways illustrated by KEGG pathway analyses. The presence of microRNAs identified in jute was validated by stem-loop RT-PCR followed by end point PCR and qPCR for randomly selected 20 known and novel microRNAs. This study exhaustively identifies microRNAs and their target genes in jute which will ultimately pave the way for understanding their role in this crop and other crops.

Origin and spread of photosynthesis based upon conserved sequence features in key bacteriochlorophyll biosynthesis proteins.

Science.gov (United States)

Gupta, Radhey S

2012-11-01

The origin of photosynthesis and how this capability has spread to other bacterial phyla remain important unresolved questions. I describe here a number of conserved signature indels (CSIs) in key proteins involved in bacteriochlorophyll (Bchl) biosynthesis that provide important insights in these regards. The proteins BchL and BchX, which are essential for Bchl biosynthesis, are derived by gene duplication in a common ancestor of all phototrophs. More ancient gene duplication gave rise to the BchX-BchL proteins and the NifH protein of the nitrogenase complex. The sequence alignment of NifH-BchX-BchL proteins contain two CSIs that are uniquely shared by all NifH and BchX homologs, but not by any BchL homologs. These CSIs and phylogenetic analysis of NifH-BchX-BchL protein sequences strongly suggest that the BchX homologs are ancestral to BchL and that the Bchl-based anoxygenic photosynthesis originated prior to the chlorophyll (Chl)-based photosynthesis in cyanobacteria. Another CSI in the BchX-BchL sequence alignment that is uniquely shared by all BchX homologs and the BchL sequences from Heliobacteriaceae, but absent in all other BchL homologs, suggests that the BchL homologs from Heliobacteriaceae are primitive in comparison to all other photosynthetic lineages. Several other identified CSIs in the BchN homologs are commonly shared by all proteobacterial homologs and a clade consisting of the marine unicellular Cyanobacteria (Clade C). These CSIs in conjunction with the results of phylogenetic analyses and pair-wise sequence similarity on the BchL, BchN, and BchB proteins, where the homologs from Clade C Cyanobacteria and Proteobacteria exhibited close relationship, provide strong evidence that these two groups have incurred lateral gene transfers. Additionally, phylogenetic analyses and several CSIs in the BchL-N-B proteins that are uniquely shared by all Chlorobi and Chloroflexi homologs provide evidence that the genes for these proteins have also been

Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

Science.gov (United States)

Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

2014-01-01

Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

Solexa sequencing identification of conserved and novel microRNAs in backfat of Large White and Chinese Meishan pigs.

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Chen Chen

Full Text Available The domestic pig (Sus scrofa, an important species in animal production industry, is a right model for studying adipogenesis and fat deposition. In order to expand the repertoire of porcine miRNAs and further explore potential regulatory miRNAs which have influence on adipogenesis, high-throughput Solexa sequencing approach was adopted to identify miRNAs in backfat of Large White (lean type pig and Meishan pigs (Chinese indigenous fatty pig. We identified 215 unique miRNAs comprising 75 known pre-miRNAs, of which 49 miRNA*s were first identified in our study, 73 miRNAs were overlapped in both libraries, and 140 were novelly predicted miRNAs, and 215 unique miRNAs were collectively corresponding to 235 independent genomic loci. Furthermore, we analyzed the sequence variations, seed edits and phylogenetic development of the miRNAs. 17 miRNAs were widely conserved from vertebrates to invertebrates, suggesting that these miRNAs may serve as potential evolutional biomarkers. 9 conserved miRNAs with significantly differential expressions were determined. The expression of miR-215, miR-135, miR-224 and miR-146b was higher in Large White pigs, opposite to the patterns shown by miR-1a, miR-133a, miR-122, miR-204 and miR-183. Almost all novel miRNAs could be considered pig-specific except ssc-miR-1343, miR-2320, miR-2326, miR-2411 and miR-2483 which had homologs in Bos taurus, among which ssc-miR-1343, miR-2320, miR-2411 and miR-2483 were validated in backfat tissue by stem-loop qPCR. Our results displayed a high level of concordance between the qPCR and Solexa sequencing method in 9 of 10 miRNAs comparisons except for miR-1a. Moreover, we found 2 miRNAs, miR-135 and miR-183, may exert impacts on porcine backfat development through WNT signaling pathway. In conclusion, our research develops porcine miRNAs and should be beneficial to study the adipogenesis and fat deposition of different pig breeds based on miRNAs.

Structural Conservation Despite Huge Sequence Diversity Allows EPCR Binding by the PfEMP1 Family Implicated in Severe Childhood Malaria

DEFF Research Database (Denmark)

Lau, Clinton K.Y.; Turner, Louise; Jespersen, Jakob S.

2015-01-01

with severe childhood malaria. We combine crystal structures of CIDRa1:EPCR complexes with analysis of 885 CIDRa1 sequences, showing that the EPCR-binding surfaces of CIDRa1 domains are conserved in shape and bonding potential, despite dramatic sequence diversity. Additionally, these domains mimic features...... of the natural EPCR ligand and can block this ligand interaction. Using peptides corresponding to the EPCR-binding region, antibodies can be purified from individuals in malaria-endemic regions that block EPCR binding of diverse CIDRa1 variants. This highlights the extent to which such a surface protein family......The PfEMP1 family of surface proteins is central for Plasmodium falciparum virulence and must retain the ability to bind to host receptors while also diversifying to aid immune evasion. The interaction between CIDRa1 domains of PfEMP1 and endothelial protein C receptor (EPCR) is associated...

Relative Stabilities of Conserved and Non-Conserved Structures in the OB-Fold Superfamily

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Andrei T. Alexandrescu

2009-05-01

Full Text Available The OB-fold is a diverse structure superfamily based on a β-barrel motif that is often supplemented with additional non-conserved secondary structures. Previous deletion mutagenesis and NMR hydrogen exchange studies of three OB-fold proteins showed that the structural stabilities of sites within the conserved β-barrels were larger than sites in non-conserved segments. In this work we examined a database of 80 representative domain structures currently classified as OB-folds, to establish the basis of this effect. Residue-specific values were obtained for the number of Cα-Cα distance contacts, sequence hydrophobicities, crystallographic B-factors, and theoretical B-factors calculated from a Gaussian Network Model. All four parameters point to a larger average flexibility for the non-conserved structures compared to the conserved β-barrels. The theoretical B-factors and contact densities show the highest sensitivity.Our results suggest a model of protein structure evolution in which novel structural features develop at the periphery of conserved motifs. Core residues are more resistant to structural changes during evolution since their substitution would disrupt a larger number of interactions. Similar factors are likely to account for the differences in stability to unfolding between conserved and non-conserved structures.

Inhibition of Hepatitis C Virus in Mice by a Small Interfering RNA Targeting a Highly Conserved Sequence in Viral IRES Pseudoknot.

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Jae-Su Moon

Full Text Available The hepatitis C virus (HCV internal ribosome entry site (IRES that directs cap-independent viral translation is a primary target for small interfering RNA (siRNA-based HCV antiviral therapy. However, identification of potent siRNAs against HCV IRES by bioinformatics-based siRNA design is a challenging task given the complexity of HCV IRES secondary and tertiary structures and association with multiple proteins, which can also dynamically change the structure of this cis-acting RNA element. In this work, we utilized siRNA tiling approach whereby siRNAs were tiled with overlapping sequences that were shifted by one or two nucleotides over the HCV IRES stem-loop structures III and IV spanning nucleotides (nts 277-343. Based on their antiviral activity, we mapped a druggable region (nts 313-343 where the targets of potent siRNAs were enriched. siIE22, which showed the greatest anti-HCV potency, targeted a highly conserved sequence across diverse HCV genotypes, locating within the IRES subdomain IIIf involved in pseudoknot formation. Stepwise target shifting toward the 5' or 3' direction by 1 or 2 nucleotides reduced the antiviral potency of siIE22, demonstrating the importance of siRNA accessibility to this highly structured and sequence-conserved region of HCV IRES for RNA interference. Nanoparticle-mediated systemic delivery of the stability-improved siIE22 derivative gs_PS1 siIE22, which contains a single phosphorothioate linkage on the guide strand, reduced the serum HCV genome titer by more than 4 log10 in a xenograft mouse model for HCV replication without generation of resistant variants. Our results provide a strategy for identifying potent siRNA species against a highly structured RNA target and offer a potential pan-HCV genotypic siRNA therapy that might be beneficial for patients resistant to current treatment regimens.

Comparative analysis of function and interaction of transcription factors in nematodes: Extensive conservation of orthology coupled to rapid sequence evolution

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Singh Rama S

2008-08-01

Full Text Available Abstract Background Much of the morphological diversity in eukaryotes results from differential regulation of gene expression in which transcription factors (TFs play a central role. The nematode Caenorhabditis elegans is an established model organism for the study of the roles of TFs in controlling the spatiotemporal pattern of gene expression. Using the fully sequenced genomes of three Caenorhabditid nematode species as well as genome information from additional more distantly related organisms (fruit fly, mouse, and human we sought to identify orthologous TFs and characterized their patterns of evolution. Results We identified 988 TF genes in C. elegans, and inferred corresponding sets in C. briggsae and C. remanei, containing 995 and 1093 TF genes, respectively. Analysis of the three gene sets revealed 652 3-way reciprocal 'best hit' orthologs (nematode TF set, approximately half of which are zinc finger (ZF-C2H2 and ZF-C4/NHR types and HOX family members. Examination of the TF genes in C. elegans and C. briggsae identified the presence of significant tandem clustering on chromosome V, the majority of which belong to ZF-C4/NHR family. We also found evidence for lineage-specific duplications and rapid evolution of many of the TF genes in the two species. A search of the TFs conserved among nematodes in Drosophila melanogaster, Mus musculus and Homo sapiens revealed 150 reciprocal orthologs, many of which are associated with important biological processes and human diseases. Finally, a comparison of the sequence, gene interactions and function indicates that nematode TFs conserved across phyla exhibit significantly more interactions and are enriched in genes with annotated mutant phenotypes compared to those that lack orthologs in other species. Conclusion Our study represents the first comprehensive genome-wide analysis of TFs across three nematode species and other organisms. The findings indicate substantial conservation of transcription

Simple connection between conservation laws in the Korteweg--de Vriesand sine-Gordon systems

International Nuclear Information System (INIS)

Chodos, A.

1980-01-01

An infinite sequence of conserved quantities follows from the Lax representation in both the Korteweg--de Vries and sine-Gordon systems. We show that these two sequences are related by a simple substitution. In an appendix, two different methods of deriving conservation laws from the Lax representation are presented

Identification and characterization of putative conserved IAM ...

African Journals Online (AJOL)

Available putative AMI sequences from a wide array of monocot and dicot plants were identified and the phylogenetic tree was constructed and analyzed. We identified in this tree, a clade that contained sequences from species across the plant kingdom suggesting that AMI is conserved and may have a primary role in plant ...

The putative Leishmania telomerase RNA (LeishTER undergoes trans-splicing and contains a conserved template sequence.

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Elton J R Vasconcelos

Full Text Available Telomerase RNAs (TERs are highly divergent between species, varying in size and sequence composition. Here, we identify a candidate for the telomerase RNA component of Leishmania genus, which includes species that cause leishmaniasis, a neglected tropical disease. Merging a thorough computational screening combined with RNA-seq evidence, we mapped a non-coding RNA gene localized in a syntenic locus on chromosome 25 of five Leishmania species that shares partial synteny with both Trypanosoma brucei TER locus and a putative TER candidate-containing locus of Crithidia fasciculata. Using target-driven molecular biology approaches, we detected a ∼2,100 nt transcript (LeishTER that contains a 5' spliced leader (SL cap, a putative 3' polyA tail and a predicted C/D box snoRNA domain. LeishTER is expressed at similar levels in the logarithmic and stationary growth phases of promastigote forms. A 5'SL capped LeishTER co-immunoprecipitated and co-localized with the telomerase protein component (TERT in a cell cycle-dependent manner. Prediction of its secondary structure strongly suggests the existence of a bona fide single-stranded template sequence and a conserved C[U/C]GUCA motif-containing helix II, representing the template boundary element. This study paves the way for further investigations on the biogenesis of parasite TERT ribonucleoproteins (RNPs and its role in parasite telomere biology.

Structural and functional analysis of mouse Msx1 gene promoter: sequence conservation with human MSX1 promoter points at potential regulatory elements.

Science.gov (United States)

Gonzalez, S M; Ferland, L H; Robert, B; Abdelhay, E

1998-06-01

Vertebrate Msx genes are related to one of the most divergent homeobox genes of Drosophila, the muscle segment homeobox (msh) gene, and are expressed in a well-defined pattern at sites of tissue interactions. This pattern of expression is conserved in vertebrates as diverse as quail, zebrafish, and mouse in a range of sites including neural crest, appendages, and craniofacial structures. In the present work, we performed structural and functional analyses in order to identify potential cis-acting elements that may be regulating Msx1 gene expression. To this end, a 4.9-kb segment of the 5'-flanking region was sequenced and analyzed for transcription-factor binding sites. Four regions showing a high concentration of these sites were identified. Transfection assays with fragments of regulatory sequences driving the expression of the bacterial lacZ reporter gene showed that a region of 4 kb upstream of the transcription start site contains positive and negative elements responsible for controlling gene expression. Interestingly, a fragment of 130 bp seems to contain the minimal elements necessary for gene expression, as its removal completely abolishes gene expression in cultured cells. These results are reinforced by comparison of this region with the human Msx1 gene promoter, which shows extensive conservation, including many consensus binding sites, suggesting a regulatory role for them.

Evolutionary conservation of P-selectin glycoprotein ligand-1 primary structure and function

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Schapira Marc

2007-09-01

Full Text Available Abstract Background P-selectin glycoprotein ligand-1 (PSGL-1 plays a critical role in recruiting leukocytes in inflammatory lesions by mediating leukocyte rolling on selectins. Core-2 O-glycosylation of a N-terminal threonine and sulfation of at least one tyrosine residue of PSGL-1 are required for L- and P-selectin binding. Little information is available on the intra- and inter-species evolution of PSGL-1 primary structure. In addition, the evolutionary conservation of selectin binding site on PSGL-1 has not been previously examined in detail. Therefore, we performed multiple sequence alignment of PSGL-1 amino acid sequences of 14 mammals (human, chimpanzee, rhesus monkey, bovine, pig, rat, tree-shrew, bushbaby, mouse, bat, horse, cat, sheep and dog and examined mammalian PSGL-1 interactions with human selectins. Results A signal peptide was predicted in each sequence and a propeptide cleavage site was found in 9/14 species. PSGL-1 N-terminus is poorly conserved. However, each species exhibits at least one tyrosine sulfation site and, except in horse and dog, a T [D/E]PP [D/E] motif associated to the core-2 O-glycosylation of a N-terminal threonine. A mucin-like domain of 250–280 amino acids long was disclosed in all studied species. It lies between the conserved N-terminal O-glycosylated threonine (Thr-57 in human and the transmembrane domain, and contains a central region exhibiting a variable number of decameric repeats (DR. Interspecies and intraspecies polymorphisms were observed. Transmembrane and cytoplasmic domain sequences are well conserved. The moesin binding residues that serve as adaptor between PSGL-1 and Syk, and are involved in regulating PSGL-1-dependent rolling on P-selectin are perfectly conserved in all analyzed mammalian sequences. Despite a poor conservation of PSGL-1 N-terminal sequence, CHO cells co-expressing human glycosyltransferases and human, bovine, pig or rat PSGL-1 efficiently rolled on human L- or P

Conservation genetics of Iberian raptors

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Martinez–Cruz, B.

2011-12-01

Full Text Available In this paper I provide an overview of conservation genetics and describe the management actions in the wild that can benefit from conservation genetic studies. I describe the genetic factors of risk for the survival of wild species, the consequences of loss of genetic diversity, inbreeding and outbreeding depression, and the use of genetic tools to delimitate units of conservation. Then I introduce the most common applications of conservation genetics in the management of wild populations. In a second part of the paper I review the conservation genetic studies carried on the Iberian raptors. I introduce several studies on the Spanish imperial eagle, the bearded vulture, the black vulture and the red kite that were carried out using autosomal microsatellite markers and mitochondrial DNA (mtDNA sequencing. I describe studies on the lesser kestrel and Egyptian vulture that additionally applied major histocompatibility complex (MHC markers, with the purpose of incorporating the study of non–neutral variation. For every species I explain how these studies can be and/or are applied in the strategy of conservation in the wild.

Analysis of Pteridium ribosomal RNA sequences by rapid direct sequencing.

Science.gov (United States)

Tan, M K

1991-08-01

A total of 864 bases from 5 regions interspersed in the 18S and 26S rRNA molecules from various clones of Pteridium covering the general geographical distribution of the genus was analysed using a rapid rRNA sequencing technique. No base difference has been detected amongst the three major lineages, two of which apparently separated before the breakup of the ancient supercontinent, Pangaea. These regions of the rRNA sequences have thus been conserved for at least 160 million years and are here compared with other eukaryotic, especially plant rRNAs.

Universal sequence map (USM of arbitrary discrete sequences

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Almeida Jonas S

2002-02-01

Full Text Available Abstract Background For over a decade the idea of representing biological sequences in a continuous coordinate space has maintained its appeal but not been fully realized. The basic idea is that any sequence of symbols may define trajectories in the continuous space conserving all its statistical properties. Ideally, such a representation would allow scale independent sequence analysis – without the context of fixed memory length. A simple example would consist on being able to infer the homology between two sequences solely by comparing the coordinates of any two homologous units. Results We have successfully identified such an iterative function for bijective mappingψ of discrete sequences into objects of continuous state space that enable scale-independent sequence analysis. The technique, named Universal Sequence Mapping (USM, is applicable to sequences with an arbitrary length and arbitrary number of unique units and generates a representation where map distance estimates sequence similarity. The novel USM procedure is based on earlier work by these and other authors on the properties of Chaos Game Representation (CGR. The latter enables the representation of 4 unit type sequences (like DNA as an order free Markov Chain transition table. The properties of USM are illustrated with test data and can be verified for other data by using the accompanying web-based tool:http://bioinformatics.musc.edu/~jonas/usm/. Conclusions USM is shown to enable a statistical mechanics approach to sequence analysis. The scale independent representation frees sequence analysis from the need to assume a memory length in the investigation of syntactic rules.

Sequence analysis of cereal sucrose synthase genes and isolation ...

African Journals Online (AJOL)

SERVER

2007-10-18

Oct 18, 2007 ... sequencing of sucrose synthase gene fragment from sor- ghum using primers designed at their conserved exons. MATERIALS AND METHODS. Multiple sequence alignment. Sucrose synthase gene sequences of various cereals like rice, maize, and barley were accessed from NCBI Genbank database.

DNA Barcoding: Amplification and sequence analysis of rbcl and matK genome regions in three divergent plant species

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Javed Iqbal Wattoo

2016-11-01

Full Text Available Background: DNA barcoding is a novel method of species identification based on nucleotide diversity of conserved sequences. The establishment and refining of plant DNA barcoding systems is more challenging due to high genetic diversity among different species. Therefore, targeting the conserved nuclear transcribed regions would be more reliable for plant scientists to reveal genetic diversity, species discrimination and phylogeny. Methods: In this study, we amplified and sequenced the chloroplast DNA regions (matk+rbcl of Solanum nigrum, Euphorbia helioscopia and Dalbergia sissoo to study the functional annotation, homology modeling and sequence analysis to allow a more efficient utilization of these sequences among different plant species. These three species represent three families; Solanaceae, Euphorbiaceae and Fabaceae respectively. Biological sequence homology and divergence of amplified sequences was studied using Basic Local Alignment Tool (BLAST. Results: Both primers (matk+rbcl showed good amplification in three species. The sequenced regions reveled conserved genome information for future identification of different medicinal plants belonging to these species. The amplified conserved barcodes revealed different levels of biological homology after sequence analysis. The results clearly showed that the use of these conserved DNA sequences as barcode primers would be an accurate way for species identification and discrimination. Conclusion: The amplification and sequencing of conserved genome regions identified a novel sequence of matK in native species of Solanum nigrum. The findings of the study would be applicable in medicinal industry to establish DNA based identification of different medicinal plant species to monitor adulteration.

The utility of transcriptomics in fish conservation.

Science.gov (United States)

Connon, Richard E; Jeffries, Ken M; Komoroske, Lisa M; Todgham, Anne E; Fangue, Nann A

2018-01-29

There is growing recognition of the need to understand the mechanisms underlying organismal resilience (i.e. tolerance, acclimatization) to environmental change to support the conservation management of sensitive and economically important species. Here, we discuss how functional genomics can be used in conservation biology to provide a cellular-level understanding of organismal responses to environmental conditions. In particular, the integration of transcriptomics with physiological and ecological research is increasingly playing an important role in identifying functional physiological thresholds predictive of compensatory responses and detrimental outcomes, transforming the way we can study issues in conservation biology. Notably, with technological advances in RNA sequencing, transcriptome-wide approaches can now be applied to species where no prior genomic sequence information is available to develop species-specific tools and investigate sublethal impacts that can contribute to population declines over generations and undermine prospects for long-term conservation success. Here, we examine the use of transcriptomics as a means of determining organismal responses to environmental stressors and use key study examples of conservation concern in fishes to highlight the added value of transcriptome-wide data to the identification of functional response pathways. Finally, we discuss the gaps between the core science and policy frameworks and how thresholds identified through transcriptomic evaluations provide evidence that can be more readily used by resource managers. © 2018. Published by The Company of Biologists Ltd.

Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells.

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Colin R Lickwar

2017-08-01

Full Text Available The intestinal epithelium serves critical physiologic functions that are shared among all vertebrates. However, it is unknown how the transcriptional regulatory mechanisms underlying these functions have changed over the course of vertebrate evolution. We generated genome-wide mRNA and accessible chromatin data from adult intestinal epithelial cells (IECs in zebrafish, stickleback, mouse, and human species to determine if conserved IEC functions are achieved through common transcriptional regulation. We found evidence for substantial common regulation and conservation of gene expression regionally along the length of the intestine from fish to mammals and identified a core set of genes comprising a vertebrate IEC signature. We also identified transcriptional start sites and other putative regulatory regions that are differentially accessible in IECs in all 4 species. Although these sites rarely showed sequence conservation from fish to mammals, surprisingly, they drove highly conserved IEC expression in a zebrafish reporter assay. Common putative transcription factor binding sites (TFBS found at these sites in multiple species indicate that sequence conservation alone is insufficient to identify much of the functionally conserved IEC regulatory information. Among the rare, highly sequence-conserved, IEC-specific regulatory regions, we discovered an ancient enhancer upstream from her6/HES1 that is active in a distinct population of Notch-positive cells in the intestinal epithelium. Together, these results show how combining accessible chromatin and mRNA datasets with TFBS prediction and in vivo reporter assays can reveal tissue-specific regulatory information conserved across 420 million years of vertebrate evolution. We define an IEC transcriptional regulatory network that is shared between fish and mammals and establish an experimental platform for studying how evolutionarily distilled regulatory information commonly controls IEC development

Comparative sequence analysis of Solanum and Arabidopsis in a hot spot for pathogen resistance on potato chromosome V reveals a patchwork of conserved and rapidly evolving genome segments

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Bruggmann Rémy

2007-05-01

Full Text Available Abstract Background Quantitative phenotypic variation of agronomic characters in crop plants is controlled by environmental and genetic factors (quantitative trait loci = QTL. To understand the molecular basis of such QTL, the identification of the underlying genes is of primary interest and DNA sequence analysis of the genomic regions harboring QTL is a prerequisite for that. QTL mapping in potato (Solanum tuberosum has identified a region on chromosome V tagged by DNA markers GP21 and GP179, which contains a number of important QTL, among others QTL for resistance to late blight caused by the oomycete Phytophthora infestans and to root cyst nematodes. Results To obtain genomic sequence for the targeted region on chromosome V, two local BAC (bacterial artificial chromosome contigs were constructed and sequenced, which corresponded to parts of the homologous chromosomes of the diploid, heterozygous genotype P6/210. Two contiguous sequences of 417,445 and 202,781 base pairs were assembled and annotated. Gene-by-gene co-linearity was disrupted by non-allelic insertions of retrotransposon elements, stretches of diverged intergenic sequences, differences in gene content and gene order. The latter was caused by inversion of a 70 kbp genomic fragment. These features were also found in comparison to orthologous sequence contigs from three homeologous chromosomes of Solanum demissum, a wild tuber bearing species. Functional annotation of the sequence identified 48 putative open reading frames (ORF in one contig and 22 in the other, with an average of one ORF every 9 kbp. Ten ORFs were classified as resistance-gene-like, 11 as F-box-containing genes, 13 as transposable elements and three as transcription factors. Comparing potato to Arabidopsis thaliana annotated proteins revealed five micro-syntenic blocks of three to seven ORFs with A. thaliana chromosomes 1, 3 and 5. Conclusion Comparative sequence analysis revealed highly conserved collinear regions

Isolation, sequence identification and tissue expression profile of a ...

African Journals Online (AJOL)

The complete expressed sequence tag (CDS) sequence of Banna mini-pig inbred line (BMI) ribokinase gene (RBKS) was amplified using the reverse transcription-polymerase chain reaction (RT-PCR) based on the conserved sequence information of the cattle or other mammals and known highly homologous swine ESTs.

Total sequence decomposition distinguishes functional modules, "molegos" in apurinic/apyrimidinic endonucleases

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Braun Werner

2002-11-01

Full Text Available Abstract Background Total sequence decomposition, using the web-based MASIA tool, identifies areas of conservation in aligned protein sequences. By structurally annotating these motifs, the sequence can be parsed into individual building blocks, molecular legos ("molegos", that can eventually be related to function. Here, the approach is applied to the apurinic/apyrimidinic endonuclease (APE DNA repair proteins, essential enzymes that have been highly conserved throughout evolution. The APEs, DNase-1 and inositol 5'-polyphosphate phosphatases (IPP form a superfamily that catalyze metal ion based phosphorolysis, but recognize different substrates. Results MASIA decomposition of APE yielded 12 sequence motifs, 10 of which are also structurally conserved within the family and are designated as molegos. The 12 motifs include all the residues known to be essential for DNA cleavage by APE. Five of these molegos are sequentially and structurally conserved in DNase-1 and the IPP family. Correcting the sequence alignment to match the residues at the ends of two of the molegos that are absolutely conserved in each of the three families greatly improved the local structural alignment of APEs, DNase-1 and synaptojanin. Comparing substrate/product binding of molegos common to DNase-1 showed that those distinctive for APEs are not directly involved in cleavage, but establish protein-DNA interactions 3' to the abasic site. These additional bonds enhance both specific binding to damaged DNA and the processivity of APE1. Conclusion A modular approach can improve structurally predictive alignments of homologous proteins with low sequence identity and reveal residues peripheral to the traditional "active site" that control the specificity of enzymatic activity.

In silico Analysis of 3′-End-Processing Signals in Aspergillus oryzae Using Expressed Sequence Tags and Genomic Sequencing Data

Science.gov (United States)

Tanaka, Mizuki; Sakai, Yoshifumi; Yamada, Osamu; Shintani, Takahiro; Gomi, Katsuya

2011-01-01

To investigate 3′-end-processing signals in Aspergillus oryzae, we created a nucleotide sequence data set of the 3′-untranslated region (3′ UTR) plus 100 nucleotides (nt) sequence downstream of the poly(A) site using A. oryzae expressed sequence tags and genomic sequencing data. This data set comprised 1065 sequences derived from 1042 unique genes. The average 3′ UTR length in A. oryzae was 241 nt, which is greater than that in yeast but similar to that in plants. The 3′ UTR and 100 nt sequence downstream of the poly(A) site is notably U-rich, while the region located 15–30 nt upstream of the poly(A) site is markedly A-rich. The most frequently found hexanucleotide in this A-rich region is AAUGAA, although this sequence accounts for only 6% of all transcripts. These data suggested that A. oryzae has no highly conserved sequence element equivalent to AAUAAA, a mammalian polyadenylation signal. We identified that putative 3′-end-processing signals in A. oryzae, while less well conserved than those in mammals, comprised four sequence elements: the furthest upstream U-rich element, A-rich sequence, cleavage site, and downstream U-rich element flanking the cleavage site. Although these putative 3′-end-processing signals are similar to those in yeast and plants, some notable differences exist between them. PMID:21586533

International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons

Science.gov (United States)

Olson, Nathan D.; Lund, Steven P.; Zook, Justin M.; Rojas-Cornejo, Fabiola; Beck, Brian; Foy, Carole; Huggett, Jim; Whale, Alexandra S.; Sui, Zhiwei; Baoutina, Anna; Dobeson, Michael; Partis, Lina; Morrow, Jayne B.

2015-01-01

This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA) sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1) identity of biologically conserved position, (2) ratio of 16S rRNA gene copies featuring identified variants, and (3) the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies. PMID:27077030

International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons

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Nathan D. Olson

2015-03-01

Full Text Available This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1 identity of biologically conserved position, (2 ratio of 16S rRNA gene copies featuring identified variants, and (3 the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies.

Sequence of a cDNA encoding turtle high mobility group 1 protein.

Science.gov (United States)

Zheng, Jifang; Hu, Bi; Wu, Duansheng

2005-07-01

In order to understand sequence information about turtle HMG1 gene, a cDNA encoding HMG1 protein of the Chinese soft-shell turtle (Pelodiscus sinensis) was amplified by RT-PCR from kidney total RNA, and was cloned, sequenced and analyzed. The results revealed that the open reading frame (ORF) of turtle HMG1 cDNA is 606 bp long. The ORF codifies 202 amino acid residues, from which two DNA-binding domains and one polyacidic region are derived. The DNA-binding domains share higher amino acid identity with homologues sequences of chicken (96.5%) and mammalian (74%) than homologues sequence of rainbow trout (67%). The polyacidic region shows 84.6% amino acid homology with the equivalent region of chicken HMG1 cDNA. Turtle HMG1 protein contains 3 Cys residues located at completely conserved positions. Conservation in sequence and structure suggests that the functions of turtle HMG1 cDNA may be highly conserved during evolution. To our knowledge, this is the first report of HMG1 cDNA sequence in any reptilian.

Mitochondrial genome sequences illuminate maternal lineages of conservation concern in a rare carnivore

Science.gov (United States)

Brian J. Knaus; Richard Cronn; Aaron Liston; Kristine Pilgrim; Michael K. Schwartz

2011-01-01

Science-based wildlife management relies on genetic information to infer population connectivity and identify conservation units. The most commonly used genetic marker for characterizing animal biodiversity and identifying maternal lineages is the mitochondrial genome. Mitochondrial genotyping figures prominently in conservation and management plans, with much of the...

Low-pass shotgun sequencing of the barley genome facilitates rapid identification of genes, conserved non-coding sequences and novel repeats

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Graner Andreas

2008-10-01

Full Text Available Abstract Background Barley has one of the largest and most complex genomes of all economically important food crops. The rise of new short read sequencing technologies such as Illumina/Solexa permits such large genomes to be effectively sampled at relatively low cost. Based on the corresponding sequence reads a Mathematically Defined Repeat (MDR index can be generated to map repetitive regions in genomic sequences. Results We have generated 574 Mbp of Illumina/Solexa sequences from barley total genomic DNA, representing about 10% of a genome equivalent. From these sequences we generated an MDR index which was then used to identify and mark repetitive regions in the barley genome. Comparison of the MDR plots with expert repeat annotation drawing on the information already available for known repetitive elements revealed a significant correspondence between the two methods. MDR-based annotation allowed for the identification of dozens of novel repeat sequences, though, which were not recognised by hand-annotation. The MDR data was also used to identify gene-containing regions by masking of repetitive sequences in eight de-novo sequenced bacterial artificial chromosome (BAC clones. For half of the identified candidate gene islands indeed gene sequences could be identified. MDR data were only of limited use, when mapped on genomic sequences from the closely related species Triticum monococcum as only a fraction of the repetitive sequences was recognised. Conclusion An MDR index for barley, which was obtained by whole-genome Illumina/Solexa sequencing, proved as efficient in repeat identification as manual expert annotation. Circumventing the labour-intensive step of producing a specific repeat library for expert annotation, an MDR index provides an elegant and efficient resource for the identification of repetitive and low-copy (i.e. potentially gene-containing sequences regions in uncharacterised genomic sequences. The restriction that a particular

The identification and functional annotation of RNA structures conserved in vertebrates

DEFF Research Database (Denmark)

Seemann, Ernst Stefan; Mirza, Aashiq Hussain; Hansen, Claus

2017-01-01

Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for Conserved RNA Structures (CRSs), leveraging structure-b......-structured counterparts. Our findings of transcribed uncharacterized regulatory regions that contain CRSs support their RNA-mediated functionality.......Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for Conserved RNA Structures (CRSs), leveraging structure......-based, rather than sequence-based, alignments. After careful correction for sequence identity and GC content, we predict ~516k human genomic regions containing CRSs. We find that a substantial fraction of human-mouse CRS regions (i) co-localize consistently with binding sites of the same RNA binding proteins...

Identification of conserved regulatory elements by comparative genome analysis

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Jareborg Niclas

2003-05-01

Full Text Available Abstract Background For genes that have been successfully delineated within the human genome sequence, most regulatory sequences remain to be elucidated. The annotation and interpretation process requires additional data resources and significant improvements in computational methods for the detection of regulatory regions. One approach of growing popularity is based on the preferential conservation of functional sequences over the course of evolution by selective pressure, termed 'phylogenetic footprinting'. Mutations are more likely to be disruptive if they appear in functional sites, resulting in a measurable difference in evolution rates between functional and non-functional genomic segments. Results We have devised a flexible suite of methods for the identification and visualization of conserved transcription-factor-binding sites. The system reports those putative transcription-factor-binding sites that are both situated in conserved regions and located as pairs of sites in equivalent positions in alignments between two orthologous sequences. An underlying collection of metazoan transcription-factor-binding profiles was assembled to facilitate the study. This approach results in a significant improvement in the detection of transcription-factor-binding sites because of an increased signal-to-noise ratio, as demonstrated with two sets of promoter sequences. The method is implemented as a graphical web application, ConSite, which is at the disposal of the scientific community at http://www.phylofoot.org/. Conclusions Phylogenetic footprinting dramatically improves the predictive selectivity of bioinformatic approaches to the analysis of promoter sequences. ConSite delivers unparalleled performance using a novel database of high-quality binding models for metazoan transcription factors. With a dynamic interface, this bioinformatics tool provides broad access to promoter analysis with phylogenetic footprinting.

Structural and Sequence Similarities of Hydra Xeroderma Pigmentosum A Protein to Human Homolog Suggest Early Evolution and Conservation

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Apurva Barve

2013-01-01

Full Text Available Xeroderma pigmentosum group A (XPA is a protein that binds to damaged DNA, verifies presence of a lesion, and recruits other proteins of the nucleotide excision repair (NER pathway to the site. Though its homologs from yeast, Drosophila, humans, and so forth are well studied, XPA has not so far been reported from protozoa and lower animal phyla. Hydra is a fresh-water cnidarian with a remarkable capacity for regeneration and apparent lack of organismal ageing. Cnidarians are among the first metazoa with a defined body axis, tissue grade organisation, and nervous system. We report here for the first time presence of XPA gene in hydra. Putative protein sequence of hydra XPA contains nuclear localization signal and bears the zinc-finger motif. It contains two conserved Pfam domains and various characterized features of XPA proteins like regions for binding to excision repair cross-complementing protein-1 (ERCC1 and replication protein A 70 kDa subunit (RPA70 proteins. Hydra XPA shows a high degree of similarity with vertebrate homologs and clusters with deuterostomes in phylogenetic analysis. Homology modelling corroborates the very close similarity between hydra and human XPA. The protein thus most likely functions in hydra in the same manner as in other animals, indicating that it arose early in evolution and has been conserved across animal phyla.

Genome-wide discovery of novel and conserved microRNAs in white shrimp (Litopenaeus vannamei).

Science.gov (United States)

Xi, Qian-Yun; Xiong, Yuan-Yan; Wang, Yuan-Mei; Cheng, Xiao; Qi, Qi-En; Shu, Gang; Wang, Song-Bo; Wang, Li-Na; Gao, Ping; Zhu, Xiao-Tong; Jiang, Qing-Yan; Zhang, Yong-Liang; Liu, Li

2015-01-01

Of late years, a large amount of conserved and species-specific microRNAs (miRNAs) have been performed on identification from species which are economically important but lack a full genome sequence. In this study, Solexa deep sequencing and cross-species miRNA microarray were used to detect miRNAs in white shrimp. We identified 239 conserved miRNAs, 14 miRNA* sequences and 20 novel miRNAs by bioinformatics analysis from 7,561,406 high-quality reads representing 325,370 distinct sequences. The all 20 novel miRNAs were species-specific in white shrimp and not homologous in other species. Using the conserved miRNAs from the miRBase database as a query set to search for homologs from shrimp expressed sequence tags (ESTs), 32 conserved computationally predicted miRNAs were discovered in shrimp. In addition, using microarray analysis in the shrimp fed with Panax ginseng polysaccharide complex, 151 conserved miRNAs were identified, 18 of which were significant up-expression, while 49 miRNAs were significant down-expression. In particular, qRT-PCR analysis was also performed for nine miRNAs in three shrimp tissues such as muscle, gill and hepatopancreas. Results showed that these miRNAs expression are tissue specific. Combining results of the three methods, we detected 20 novel and 394 conserved miRNAs. Verification with quantitative reverse transcription (qRT-PCR) and Northern blot showed a high confidentiality of data. The study provides the first comprehensive specific miRNA profile of white shrimp, which includes useful information for future investigations into the function of miRNAs in regulation of shrimp development and immunology.

Sequence walkers: a graphical method to display how binding proteins interact with DNA or RNA sequences | Center for Cancer Research

Science.gov (United States)

A graphical method is presented for displaying how binding proteins and other macromolecules interact with individual bases of nucleotide sequences. Characters representing the sequence are either oriented normally and placed above a line indicating favorable contact, or upside-down and placed below the line indicating unfavorable contact. The positive or negative height of each letter shows the contribution of that base to the average sequence conservation of the binding site, as represented by a sequence logo.

Sequence of human protamine 2 cDNA

Energy Technology Data Exchange (ETDEWEB)

Domenjoud, L; Fronia, C; Uhde, F; Engel, W [Universitaet Goettingen (West Germany)

1988-08-11

The authors report the cloning and sequencing of a cDNA clone for human protamine 2 (hp2), isolated from a human testis cDNA library cloned in the vector {lambda}-gt11. A 66mer oligonucleotide, that corresponds to an amino acid sequence which is highly conserved between hp2 and mouse protamine 2 (mp2) served as hybridization probe. The homology between the amino acid sequence deduced from our cDNA and the published amino acid sequence for hp2 is 100%.

Comparative analysis of catfish BAC end sequences with the zebrafish genome

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Abernathy Jason

2009-12-01

Full Text Available Abstract Background Comparative mapping is a powerful tool to transfer genomic information from sequenced genomes to closely related species for which whole genome sequence data are not yet available. However, such an approach is still very limited in catfish, the most important aquaculture species in the United States. This project was initiated to generate additional BAC end sequences and demonstrate their applications in comparative mapping in catfish. Results We reported the generation of 43,000 BAC end sequences and their applications for comparative genome analysis in catfish. Using these and the additional 20,000 existing BAC end sequences as a resource along with linkage mapping and existing physical map, conserved syntenic regions were identified between the catfish and zebrafish genomes. A total of 10,943 catfish BAC end sequences (17.3% had significant BLAST hits to the zebrafish genome (cutoff value ≤ e-5, of which 3,221 were unique gene hits, providing a platform for comparative mapping based on locations of these genes in catfish and zebrafish. Genetic linkage mapping of microsatellites associated with contigs allowed identification of large conserved genomic segments and construction of super scaffolds. Conclusion BAC end sequences and their associated polymorphic markers are great resources for comparative genome analysis in catfish. Highly conserved chromosomal regions were identified to exist between catfish and zebrafish. However, it appears that the level of conservation at local genomic regions are high while a high level of chromosomal shuffling and rearrangements exist between catfish and zebrafish genomes. Orthologous regions established through comparative analysis should facilitate both structural and functional genome analysis in catfish.

Evaluation of the conserve flavin reductase gene from three ...

African Journals Online (AJOL)

STORAGESEVER

2009-12-15

Dec 15, 2009 ... means of PCR technique. The nucleic acid sequences of the PCR primers were designed using conserved nucleic acid sequences of the flavin reductase enzyme from. Rhodococcus sp. strain IGTS8. The oligonucleotide primers were as follows: 5'-GAA TTC ATG TCT GAC. AAG CCG AAT GCC-3' (forward) ...

Perception Enhancement using Visual Attributes in Sequence Motif Visualization

OpenAIRE

Oon, Yin; Lee, Nung; Kok, Wei

2016-01-01

Sequence logo is a well-accepted scientific method to visualize the conservation characteristics of biological sequence motifs. Previous studies found that using sequence logo graphical representation for scientific evidence reports or arguments could seriously cause biases and misinterpretation by users. This study investigates on the visual attributes performance of a sequence logo in helping users to perceive and interpret the information based on preattentive theories and Gestalt principl...

De novo prediction of structured RNAs from genomic sequences

DEFF Research Database (Denmark)

Gorodkin, Jan; Hofacker, Ivo L.; Þórarinsson, Elfar

2010-01-01

currently available, because evolutionary conservation highlights functionally important regions. Conserved secondary structure, rather than primary sequence, is the hallmark of many functionally important RNAs, because compensatory substitutions in base-paired regions preserve structure. Unfortunately...

RNA expression in a cartilaginous fish cell line reveals ancient 3′ noncoding regions highly conserved in vertebrates

Science.gov (United States)

Forest, David; Nishikawa, Ryuhei; Kobayashi, Hiroshi; Parton, Angela; Bayne, Christopher J.; Barnes, David W.

2007-01-01

We have established a cartilaginous fish cell line [Squalus acanthias embryo cell line (SAE)], a mesenchymal stem cell line derived from the embryo of an elasmobranch, the spiny dogfish shark S. acanthias. Elasmobranchs (sharks and rays) first appeared >400 million years ago, and existing species provide useful models for comparative vertebrate cell biology, physiology, and genomics. Comparative vertebrate genomics among evolutionarily distant organisms can provide sequence conservation information that facilitates identification of critical coding and noncoding regions. Although these genomic analyses are informative, experimental verification of functions of genomic sequences depends heavily on cell culture approaches. Using ESTs defining mRNAs derived from the SAE cell line, we identified lengthy and highly conserved gene-specific nucleotide sequences in the noncoding 3′ UTRs of eight genes involved in the regulation of cell growth and proliferation. Conserved noncoding 3′ mRNA regions detected by using the shark nucleotide sequences as a starting point were found in a range of other vertebrate orders, including bony fish, birds, amphibians, and mammals. Nucleotide identity of shark and human in these regions was remarkably well conserved. Our results indicate that highly conserved gene sequences dating from the appearance of jawed vertebrates and representing potential cis-regulatory elements can be identified through the use of cartilaginous fish as a baseline. Because the expression of genes in the SAE cell line was prerequisite for their identification, this cartilaginous fish culture system also provides a physiologically valid tool to test functional hypotheses on the role of these ancient conserved sequences in comparative cell biology. PMID:17227856

Combining protein sequence, structure, and dynamics: A novel approach for functional evolution analysis of PAS domain superfamily.

Science.gov (United States)

Dong, Zheng; Zhou, Hongyu; Tao, Peng

2018-02-01

PAS domains are widespread in archaea, bacteria, and eukaryota, and play important roles in various functions. In this study, we aim to explore functional evolutionary relationship among proteins in the PAS domain superfamily in view of the sequence-structure-dynamics-function relationship. We collected protein sequences and crystal structure data from RCSB Protein Data Bank of the PAS domain superfamily belonging to three biological functions (nucleotide binding, photoreceptor activity, and transferase activity). Protein sequences were aligned and then used to select sequence-conserved residues and build phylogenetic tree. Three-dimensional structure alignment was also applied to obtain structure-conserved residues. The protein dynamics were analyzed using elastic network model (ENM) and validated by molecular dynamics (MD) simulation. The result showed that the proteins with same function could be grouped by sequence similarity, and proteins in different functional groups displayed statistically significant difference in their vibrational patterns. Interestingly, in all three functional groups, conserved amino acid residues identified by sequence and structure conservation analysis generally have a lower fluctuation than other residues. In addition, the fluctuation of conserved residues in each biological function group was strongly correlated with the corresponding biological function. This research suggested a direct connection in which the protein sequences were related to various functions through structural dynamics. This is a new attempt to delineate functional evolution of proteins using the integrated information of sequence, structure, and dynamics. © 2017 The Protein Society.

High throughput sequencing of small RNA component of leaves and inflorescence revealed conserved and novel miRNAs as well as phasiRNA loci in chickpea.

Science.gov (United States)

Srivastava, Sangeeta; Zheng, Yun; Kudapa, Himabindu; Jagadeeswaran, Guru; Hivrale, Vandana; Varshney, Rajeev K; Sunkar, Ramanjulu

2015-06-01

Among legumes, chickpea (Cicer arietinum L.) is the second most important crop after soybean. MicroRNAs (miRNAs) play important roles by regulating target gene expression important for plant development and tolerance to stress conditions. Additionally, recently discovered phased siRNAs (phasiRNAs), a new class of small RNAs, are abundantly produced in legumes. Nevertheless, little is known about these regulatory molecules in chickpea. The small RNA population was sequenced from leaves and flowers of chickpea to identify conserved and novel miRNAs as well as phasiRNAs/phasiRNA loci. Bioinformatics analysis revealed 157 miRNA loci for the 96 highly conserved and known miRNA homologs belonging to 38 miRNA families in chickpea. Furthermore, 20 novel miRNAs belonging to 17 miRNA families were identified. Sequence analysis revealed approximately 60 phasiRNA loci. Potential target genes likely to be regulated by these miRNAs were predicted and some were confirmed by modified 5' RACE assay. Predicted targets are mostly transcription factors that might be important for developmental processes, and others include superoxide dismutases, plantacyanin, laccases and F-box proteins that could participate in stress responses and protein degradation. Overall, this study provides an inventory of miRNA-target gene interactions for chickpea, useful for the comparative analysis of small RNAs among legumes. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Phylogenetic analysis reveals conservation and diversification of micro RNA166 genes among diverse plant species.

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Barik, Suvakanta; SarkarDas, Shabari; Singh, Archita; Gautam, Vibhav; Kumar, Pramod; Majee, Manoj; Sarkar, Ananda K

2014-01-01

Similar to the majority of the microRNAs, mature miR166s are derived from multiple members of MIR166 genes (precursors) and regulate various aspects of plant development by negatively regulating their target genes (Class III HD-ZIP). The evolutionary conservation or functional diversification of miRNA166 family members remains elusive. Here, we show the phylogenetic relationships among MIR166 precursor and mature sequences from three diverse model plant species. Despite strong conservation, some mature miR166 sequences, such as ppt-miR166m, have undergone sequence variation. Critical sequence variation in ppt-miR166m has led to functional diversification, as it targets non-HD-ZIPIII gene transcript (s). MIR166 precursor sequences have diverged in a lineage specific manner, and both precursors and mature osa-miR166i/j are highly conserved. Interestingly, polycistronic MIR166s were present in Physcomitrella and Oryza but not in Arabidopsis. The nature of cis-regulatory motifs on the upstream promoter sequences of MIR166 genes indicates their possible contribution to the functional variation observed among miR166 species. Copyright © 2013 Elsevier Inc. All rights reserved.

Conserved upstream open reading frames in higher plants

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Schultz Carolyn J

2008-07-01

Full Text Available Abstract Background Upstream open reading frames (uORFs can down-regulate the translation of the main open reading frame (mORF through two broad mechanisms: ribosomal stalling and reducing reinitiation efficiency. In distantly related plants, such as rice and Arabidopsis, it has been found that conserved uORFs are rare in these transcriptomes with approximately 100 loci. It is unclear how prevalent conserved uORFs are in closely related plants. Results We used a homology-based approach to identify conserved uORFs in five cereals (monocots that could potentially regulate translation. Our approach used a modified reciprocal best hit method to identify putative orthologous sequences that were then analysed by a comparative R-nomics program called uORFSCAN to find conserved uORFs. Conclusion This research identified new genes that may be controlled at the level of translation by conserved uORFs. We report that conserved uORFs are rare (

ASAP: Amplification, sequencing & annotation of plastomes

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Folta Kevin M

2005-12-01

Full Text Available Abstract Background Availability of DNA sequence information is vital for pursuing structural, functional and comparative genomics studies in plastids. Traditionally, the first step in mining the valuable information within a chloroplast genome requires sequencing a chloroplast plasmid library or BAC clones. These activities involve complicated preparatory procedures like chloroplast DNA isolation or identification of the appropriate BAC clones to be sequenced. Rolling circle amplification (RCA is being used currently to amplify the chloroplast genome from purified chloroplast DNA and the resulting products are sheared and cloned prior to sequencing. Herein we present a universal high-throughput, rapid PCR-based technique to amplify, sequence and assemble plastid genome sequence from diverse species in a short time and at reasonable cost from total plant DNA, using the large inverted repeat region from strawberry and peach as proof of concept. The method exploits the highly conserved coding regions or intergenic regions of plastid genes. Using an informatics approach, chloroplast DNA sequence information from 5 available eudicot plastomes was aligned to identify the most conserved regions. Cognate primer pairs were then designed to generate ~1 – 1.2 kb overlapping amplicons from the inverted repeat region in 14 diverse genera. Results 100% coverage of the inverted repeat region was obtained from Arabidopsis, tobacco, orange, strawberry, peach, lettuce, tomato and Amaranthus. Over 80% coverage was obtained from distant species, including Ginkgo, loblolly pine and Equisetum. Sequence from the inverted repeat region of strawberry and peach plastome was obtained, annotated and analyzed. Additionally, a polymorphic region identified from gel electrophoresis was sequenced from tomato and Amaranthus. Sequence analysis revealed large deletions in these species relative to tobacco plastome thus exhibiting the utility of this method for structural and

Structure-sequence based analysis for identification of conserved regions in proteins

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Zemla, Adam T; Zhou, Carol E; Lam, Marisa W; Smith, Jason R; Pardes, Elizabeth

2013-05-28

Disclosed are computational methods, and associated hardware and software products for scoring conservation in a protein structure based on a computationally identified family or cluster of protein structures. A method of computationally identifying a family or cluster of protein structures in also disclosed herein.

Differential sequence diversity at merozoite surface protein-1 locus of Plasmodium knowlesi from humans and macaques in Thailand.

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Putaporntip, Chaturong; Thongaree, Siriporn; Jongwutiwes, Somchai

2013-08-01

To determine the genetic diversity and potential transmission routes of Plasmodium knowlesi, we analyzed the complete nucleotide sequence of the gene encoding the merozoite surface protein-1 of this simian malaria (Pkmsp-1), an asexual blood-stage vaccine candidate, from naturally infected humans and macaques in Thailand. Analysis of Pkmsp-1 sequences from humans (n=12) and monkeys (n=12) reveals five conserved and four variable domains. Most nucleotide substitutions in conserved domains were dimorphic whereas three of four variable domains contained complex repeats with extensive sequence and size variation. Besides purifying selection in conserved domains, evidence of intragenic recombination scattering across Pkmsp-1 was detected. The number of haplotypes, haplotype diversity, nucleotide diversity and recombination sites of human-derived sequences exceeded that of monkey-derived sequences. Phylogenetic networks based on concatenated conserved sequences of Pkmsp-1 displayed a character pattern that could have arisen from sampling process or the presence of two independent routes of P. knowlesi transmission, i.e. from macaques to human and from human to humans in Thailand. Copyright © 2013 Elsevier B.V. All rights reserved.

In Silico Characterization of Pectate Lyase Protein Sequences from Different Source Organisms

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Amit Kumar Dubey

2010-01-01

Full Text Available A total of 121 protein sequences of pectate lyases were subjected to homology search, multiple sequence alignment, phylogenetic tree construction, and motif analysis. The phylogenetic tree constructed revealed different clusters based on different source organisms representing bacterial, fungal, plant, and nematode pectate lyases. The multiple accessions of bacterial, fungal, nematode, and plant pectate lyase protein sequences were placed closely revealing a sequence level similarity. The multiple sequence alignment of these pectate lyase protein sequences from different source organisms showed conserved regions at different stretches with maximum homology from amino acid residues 439–467, 715–816, and 829–910 which could be used for designing degenerate primers or probes specific for pectate lyases. The motif analysis revealed a conserved Pec_Lyase_C domain uniformly observed in all pectate lyases irrespective of variable sources suggesting its possible role in structural and enzymatic functions.

Core genome conservation of Staphylococcus haemolyticus limits sequence based population structure analysis.

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Cavanagh, Jorunn Pauline; Klingenberg, Claus; Hanssen, Anne-Merethe; Fredheim, Elizabeth Aarag; Francois, Patrice; Schrenzel, Jacques; Flægstad, Trond; Sollid, Johanna Ericson

2012-06-01

The notoriously multi-resistant Staphylococcus haemolyticus is an emerging pathogen causing serious infections in immunocompromised patients. Defining the population structure is important to detect outbreaks and spread of antimicrobial resistant clones. Currently, the standard typing technique is pulsed-field gel electrophoresis (PFGE). In this study we describe novel molecular typing schemes for S. haemolyticus using multi locus sequence typing (MLST) and multi locus variable number of tandem repeats (VNTR) analysis. Seven housekeeping genes (MLST) and five VNTR loci (MLVF) were selected for the novel typing schemes. A panel of 45 human and veterinary S. haemolyticus isolates was investigated. The collection had diverse PFGE patterns (38 PFGE types) and was sampled over a 20 year-period from eight countries. MLST resolved 17 sequence types (Simpsons index of diversity [SID]=0.877) and MLVF resolved 14 repeat types (SID=0.831). We found a low sequence diversity. Phylogenetic analysis clustered the isolates in three (MLST) and one (MLVF) clonal complexes, respectively. Taken together, neither the MLST nor the MLVF scheme was suitable to resolve the population structure of this S. haemolyticus collection. Future MLVF and MLST schemes will benefit from addition of more variable core genome sequences identified by comparing different fully sequenced S. haemolyticus genomes. Copyright © 2012 Elsevier B.V. All rights reserved.

Evolutionarily conserved substrate substructures for automated annotation of enzyme superfamilies.

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Ranyee A Chiang

2008-08-01

Full Text Available The evolution of enzymes affects how well a species can adapt to new environmental conditions. During enzyme evolution, certain aspects of molecular function are conserved while other aspects can vary. Aspects of function that are more difficult to change or that need to be reused in multiple contexts are often conserved, while those that vary may indicate functions that are more easily changed or that are no longer required. In analogy to the study of conservation patterns in enzyme sequences and structures, we have examined the patterns of conservation and variation in enzyme function by analyzing graph isomorphisms among enzyme substrates of a large number of enzyme superfamilies. This systematic analysis of substrate substructures establishes the conservation patterns that typify individual superfamilies. Specifically, we determined the chemical substructures that are conserved among all known substrates of a superfamily and the substructures that are reacting in these substrates and then examined the relationship between the two. Across the 42 superfamilies that were analyzed, substantial variation was found in how much of the conserved substructure is reacting, suggesting that superfamilies may not be easily grouped into discrete and separable categories. Instead, our results suggest that many superfamilies may need to be treated individually for analyses of evolution, function prediction, and guiding enzyme engineering strategies. Annotating superfamilies with these conserved and reacting substructure patterns provides information that is orthogonal to information provided by studies of conservation in superfamily sequences and structures, thereby improving the precision with which we can predict the functions of enzymes of unknown function and direct studies in enzyme engineering. Because the method is automated, it is suitable for large-scale characterization and comparison of fundamental functional capabilities of both characterized

Evolutionarily conserved substrate substructures for automated annotation of enzyme superfamilies.

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Chiang, Ranyee A; Sali, Andrej; Babbitt, Patricia C

2008-08-01

The evolution of enzymes affects how well a species can adapt to new environmental conditions. During enzyme evolution, certain aspects of molecular function are conserved while other aspects can vary. Aspects of function that are more difficult to change or that need to be reused in multiple contexts are often conserved, while those that vary may indicate functions that are more easily changed or that are no longer required. In analogy to the study of conservation patterns in enzyme sequences and structures, we have examined the patterns of conservation and variation in enzyme function by analyzing graph isomorphisms among enzyme substrates of a large number of enzyme superfamilies. This systematic analysis of substrate substructures establishes the conservation patterns that typify individual superfamilies. Specifically, we determined the chemical substructures that are conserved among all known substrates of a superfamily and the substructures that are reacting in these substrates and then examined the relationship between the two. Across the 42 superfamilies that were analyzed, substantial variation was found in how much of the conserved substructure is reacting, suggesting that superfamilies may not be easily grouped into discrete and separable categories. Instead, our results suggest that many superfamilies may need to be treated individually for analyses of evolution, function prediction, and guiding enzyme engineering strategies. Annotating superfamilies with these conserved and reacting substructure patterns provides information that is orthogonal to information provided by studies of conservation in superfamily sequences and structures, thereby improving the precision with which we can predict the functions of enzymes of unknown function and direct studies in enzyme engineering. Because the method is automated, it is suitable for large-scale characterization and comparison of fundamental functional capabilities of both characterized and uncharacterized

Conservation of the Type IV secretion system throughout Wolbachia evolution

DEFF Research Database (Denmark)

Pichon, Samuel; Bouchon, Didier; Cordaux, Richard

2009-01-01

, encoding a T4SS were previously identified and characterized at two separate genomic loci. Using the largest data set of Wolbachia strains studied so far, we show that vir gene sequence and organization are strictly conserved among 37 Wolbachia strains inducing various phenotypes such as cytoplasmic...... incompatibility, feminization, or oogenesis in their arthropod hosts. In sharp contrast, extensive variation of genomic sequences flanking the virB8-D4 operon suggested its distinct location among Wolbachia genomes. Long term conservation of the T4SS may imply maintenance of a functional effector translocation...... system in Wolbachia, thereby suggesting the importance for the T4SS in Wolbachia biology and survival inside host cells....

Strategies for measuring evolutionary conservation of RNA secondary structures

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Hofacker Ivo L

2008-02-01

Full Text Available Abstract Background Evolutionary conservation of RNA secondary structure is a typical feature of many functional non-coding RNAs. Since almost all of the available methods used for prediction and annotation of non-coding RNA genes rely on this evolutionary signature, accurate measures for structural conservation are essential. Results We systematically assessed the ability of various measures to detect conserved RNA structures in multiple sequence alignments. We tested three existing and eight novel strategies that are based on metrics of folding energies, metrics of single optimal structure predictions, and metrics of structure ensembles. We find that the folding energy based SCI score used in the RNAz program and a simple base-pair distance metric are by far the most accurate. The use of more complex metrics like for example tree editing does not improve performance. A variant of the SCI performed particularly well on highly conserved alignments and is thus a viable alternative when only little evolutionary information is available. Surprisingly, ensemble based methods that, in principle, could benefit from the additional information contained in sub-optimal structures, perform particularly poorly. As a general trend, we observed that methods that include a consensus structure prediction outperformed equivalent methods that only consider pairwise comparisons. Conclusion Structural conservation can be measured accurately with relatively simple and intuitive metrics. They have the potential to form the basis of future RNA gene finders, that face new challenges like finding lineage specific structures or detecting mis-aligned sequences.

Analysis of Schizosaccharomyces pombe mediator reveals a set of essential subunits conserved between yeast and metazoan cells

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Spåhr, H; Samuelsen, C O; Baraznenok, V

2001-01-01

. cerevisiae share an essential protein module, which associates with nonessential speciesspecific subunits. In support of this view, sequence analysis of the conserved yeast Mediator components Med4 and Med8 reveals sequence homology to the metazoan Mediator components Trap36 and Arc32. Therefore, 8 of 10...... essential genes conserved between S. pombe and S. cerevisiae also have a metazoan homolog, indicating that an evolutionary conserved Mediator core is present in all eukaryotic cells. Our data suggest a closer functional relationship between yeast and metazoan Mediator than previously anticipated....

Subfamily logos: visualization of sequence deviations at alignment positions with high information content

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Beitz Eric

2006-06-01

Full Text Available Abstract Background Recognition of relevant sequence deviations can be valuable for elucidating functional differences between protein subfamilies. Interesting residues at highly conserved positions can then be mutated and experimentally analyzed. However, identification of such sites is tedious because automated approaches are scarce. Results Subfamily logos visualize subfamily-specific sequence deviations. The display is similar to classical sequence logos but extends into the negative range. Positive, upright characters correspond to residues which are characteristic for the subfamily, negative, upside-down characters to residues typical for the remaining sequences. The symbol height is adjusted to the information content of the alignment position. Residues which are conserved throughout do not appear. Conclusion Subfamily logos provide an intuitive display of relevant sequence deviations. The method has proven to be valid using a set of 135 aligned aquaporin sequences in which established subfamily-specific positions were readily identified by the algorithm.

G-quadruplex DNA sequences are evolutionarily conserved and associated with distinct genomic features in Saccharomyces cerevisiae.

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John A Capra

2010-07-01

Full Text Available G-quadruplex DNA is a four-stranded DNA structure formed by non-Watson-Crick base pairing between stacked sets of four guanines. Many possible functions have been proposed for this structure, but its in vivo role in the cell is still largely unresolved. We carried out a genome-wide survey of the evolutionary conservation of regions with the potential to form G-quadruplex DNA structures (G4 DNA motifs across seven yeast species. We found that G4 DNA motifs were significantly more conserved than expected by chance, and the nucleotide-level conservation patterns suggested that the motif conservation was the result of the formation of G4 DNA structures. We characterized the association of conserved and non-conserved G4 DNA motifs in Saccharomyces cerevisiae with more than 40 known genome features and gene classes. Our comprehensive, integrated evolutionary and functional analysis confirmed the previously observed associations of G4 DNA motifs with promoter regions and the rDNA, and it identified several previously unrecognized associations of G4 DNA motifs with genomic features, such as mitotic and meiotic double-strand break sites (DSBs. Conserved G4 DNA motifs maintained strong associations with promoters and the rDNA, but not with DSBs. We also performed the first analysis of G4 DNA motifs in the mitochondria, and surprisingly found a tenfold higher concentration of the motifs in the AT-rich yeast mitochondrial DNA than in nuclear DNA. The evolutionary conservation of the G4 DNA motif and its association with specific genome features supports the hypothesis that G4 DNA has in vivo functions that are under evolutionary constraint.

Cloning of the cDNA for murine von Willebrand factor and identification of orthologous genes reveals the extent of conservation among diverse species.

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Chitta, Mohan S; Duhé, Roy J; Kermode, John C

2007-05-01

Interaction of von Willebrand factor (VWF) with circulating platelets promotes hemostasis when a blood vessel is injured. The A1 domain of VWF is responsible for the initial interaction with platelets and is well conserved among species. Knowledge of the cDNA and genomic DNA sequences for human VWF allowed us to predict the cDNA sequence for murine VWF in silico and amplify its entire coding region by RT-PCR. The murine VWF cDNA has an open reading frame of 8,442 bp, encoding a protein of 2,813 amino acid residues with 83% identity to human pre-pro-VWF. The same strategy was used to predict in silico the cDNA sequence for the ortholog of VWF in a further six species. Many of these predictions diverged substantially from the putative Reference Sequences derived by ab initio methods. Our predicted sequences indicated that the VWF gene has a conserved structure of 52 exons in all seven mammalian species examined, as well as in the chicken. There is a minor structural variation in the pufferfish Takifugu rubripes insofar as the VWF gene in this species has 53 exons. Comparison of the translated amino acid sequences also revealed a high degree of conservation. In particular, the cysteine residues are conserved precisely throughout both the pro-peptide and the mature VWF sequence in all species, with a minor exception in the pufferfish VWF ortholog where two adjacent cysteine residues are omitted. The marked conservation of cysteine residues emphasizes the importance of the intricate pattern of disulfide bonds in governing the structure of pro-VWF and regulating the function of the mature VWF protein. It should also be emphasized that many of the conserved features of the VWF gene and protein were obscured when the comparison among species was based on the putative Reference Sequences instead of our predicted cDNA sequences.

Sequence of cDNAs for mammalian H2A. Z, an evolutionarily diverged but highly conserved basal histone H2A isoprotein species

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Hatch, C L; Bonner, W M

1988-02-11

The nucleotide sequences of cDNAs for the evolutionarily diverged but highly conserved basal H2A isoprotein, H2A.Z, have been determined for the rat, cow, and human. As a basal histone, H2A.Z is synthesized throughout the cell cycle at a constant rate, unlinked to DNA replication, and at a much lower rate in quiescent cells. Each of the cDNA isolates encodes the entire H2A.Z polypeptide. The human isolate is about 1.0 kilobases long. It contains a coding region of 387 nucleotides flanked by 106 nucleotides of 5'UTR and 376 nucleotides of 3'UTR, which contains a polyadenylation signal followed by a poly A tail. The bovine and rat cDNAs have 97 and 94% nucleotide positional identity to the human cDNA in the coding region and 98% in the proximal 376 nucleotides of the 3'UTR which includes the polyadenylation signal. A potential stem-forming sequence imbedded in a direct repeat is found centered at 261 nucleotides into the 3'UTR. Each of the cDNA clones could be transcribed and translated in vitro to yield H2A.Z protein. The mammalian H2A.Z cDNA coding sequences are approximately 80% similar to those in chicken and 75% to those in sea urchin.

Effects of using coding potential, sequence conservation and mRNA structure conservation for predicting pyrroly-sine containing genes

DEFF Research Database (Denmark)

Have, Christian Theil; Zambach, Sine; Christiansen, Henning

2013-01-01

for prediction of pyrrolysine incorporating genes in genomes of bacteria and archaea leading to insights about the factors driving pyrrolysine translation and identification of new gene candidates. The method predicts known conserved genes with high recall and predicts several other promising candidates...... for experimental verification. The method is implemented as a computational pipeline which is available on request....

smRNAome profiling to identify conserved and novel microRNAs in Stevia rebaudiana Bertoni

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2012-01-01

Background MicroRNAs (miRNAs) constitute a family of small RNA (sRNA) population that regulates the gene expression and plays an important role in plant development, metabolism, signal transduction and stress response. Extensive studies on miRNAs have been performed in different plants such as Arabidopsis thaliana, Oryza sativa etc. and volume of the miRNA database, mirBASE, has been increasing on day to day basis. Stevia rebaudiana Bertoni is an important perennial herb which accumulates high concentrations of diterpene steviol glycosides which contributes to its high indexed sweetening property with no calorific value. Several studies have been carried out for understanding molecular mechanism involved in biosynthesis of these glycosides, however, information about miRNAs has been lacking in S. rebaudiana. Deep sequencing of small RNAs combined with transcriptomic data is a powerful tool for identifying conserved and novel miRNAs irrespective of availability of genome sequence data. Results To identify miRNAs in S. rebaudiana, sRNA library was constructed and sequenced using Illumina genome analyzer II. A total of 30,472,534 reads representing 2,509,190 distinct sequences were obtained from sRNA library. Based on sequence similarity, we identified 100 miRNAs belonging to 34 highly conserved families. Also, we identified 12 novel miRNAs whose precursors were potentially generated from stevia EST and nucleotide sequences. All novel sequences have not been earlier described in other plant species. Putative target genes were predicted for most conserved and novel miRNAs. The predicted targets are mainly mRNA encoding enzymes regulating essential plant metabolic and signaling pathways. Conclusions This study led to the identification of 34 highly conserved miRNA families and 12 novel potential miRNAs indicating that specific miRNAs exist in stevia species. Our results provided information on stevia miRNAs and their targets building a foundation for future studies to

The most conserved genome segments for life detection on Earth and other planets.

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Isenbarger, Thomas A; Carr, Christopher E; Johnson, Sarah Stewart; Finney, Michael; Church, George M; Gilbert, Walter; Zuber, Maria T; Ruvkun, Gary

2008-12-01

On Earth, very simple but powerful methods to detect and classify broad taxa of life by the polymerase chain reaction (PCR) are now standard practice. Using DNA primers corresponding to the 16S ribosomal RNA gene, one can survey a sample from any environment for its microbial inhabitants. Due to massive meteoritic exchange between Earth and Mars (as well as other planets), a reasonable case can be made for life on Mars or other planets to be related to life on Earth. In this case, the supremely sensitive technologies used to study life on Earth, including in extreme environments, can be applied to the search for life on other planets. Though the 16S gene has become the standard for life detection on Earth, no genome comparisons have established that the ribosomal genes are, in fact, the most conserved DNA segments across the kingdoms of life. We present here a computational comparison of full genomes from 13 diverse organisms from the Archaea, Bacteria, and Eucarya to identify genetic sequences conserved across the widest divisions of life. Our results identify the 16S and 23S ribosomal RNA genes as well as other universally conserved nucleotide sequences in genes encoding particular classes of transfer RNAs and within the nucleotide binding domains of ABC transporters as the most conserved DNA sequence segments across phylogeny. This set of sequences defines a core set of DNA regions that have changed the least over billions of years of evolution and provides a means to identify and classify divergent life, including ancestrally related life on other planets.

Sequence analysis of serum albumins reveals the molecular evolution of ligand recognition properties.

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Fanali, Gabriella; Ascenzi, Paolo; Bernardi, Giorgio; Fasano, Mauro

2012-01-01

Serum albumin (SA) is a circulating protein providing a depot and carrier for many endogenous and exogenous compounds. At least seven major binding sites have been identified by structural and functional investigations mainly in human SA. SA is conserved in vertebrates, with at least 49 entries in protein sequence databases. The multiple sequence analysis of this set of entries leads to the definition of a cladistic tree for the molecular evolution of SA orthologs in vertebrates, thus showing the clustering of the considered species, with lamprey SAs (Lethenteron japonicum and Petromyzon marinus) in a separate outgroup. Sequence analysis aimed at searching conserved domains revealed that most SA sequences are made up by three repeated domains (about 600 residues), as extensively characterized for human SA. On the contrary, lamprey SAs are giant proteins (about 1400 residues) comprising seven repeated domains. The phylogenetic analysis of the SA family reveals a stringent correlation with the taxonomic classification of the species available in sequence databases. A focused inspection of the sequences of ligand binding sites in SA revealed that in all sites most residues involved in ligand binding are conserved, although the versatility towards different ligands could be peculiar of higher organisms. Moreover, the analysis of molecular links between the different sites suggests that allosteric modulation mechanisms could be restricted to higher vertebrates.

Chromosome-wide mapping of DNA methylation patterns in normal and malignant prostate cells reveals pervasive methylation of gene-associated and conserved intergenic sequences

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De Marzo Angelo M

2011-06-01

Full Text Available Abstract Background DNA methylation has been linked to genome regulation and dysregulation in health and disease respectively, and methods for characterizing genomic DNA methylation patterns are rapidly emerging. We have developed/refined methods for enrichment of methylated genomic fragments using the methyl-binding domain of the human MBD2 protein (MBD2-MBD followed by analysis with high-density tiling microarrays. This MBD-chip approach was used to characterize DNA methylation patterns across all non-repetitive sequences of human chromosomes 21 and 22 at high-resolution in normal and malignant prostate cells. Results Examining this data using computational methods that were designed specifically for DNA methylation tiling array data revealed widespread methylation of both gene promoter and non-promoter regions in cancer and normal cells. In addition to identifying several novel cancer hypermethylated 5' gene upstream regions that mediated epigenetic gene silencing, we also found several hypermethylated 3' gene downstream, intragenic and intergenic regions. The hypermethylated intragenic regions were highly enriched for overlap with intron-exon boundaries, suggesting a possible role in regulation of alternative transcriptional start sites, exon usage and/or splicing. The hypermethylated intergenic regions showed significant enrichment for conservation across vertebrate species. A sampling of these newly identified promoter (ADAMTS1 and SCARF2 genes and non-promoter (downstream or within DSCR9, C21orf57 and HLCS genes hypermethylated regions were effective in distinguishing malignant from normal prostate tissues and/or cell lines. Conclusions Comparison of chromosome-wide DNA methylation patterns in normal and malignant prostate cells revealed significant methylation of gene-proximal and conserved intergenic sequences. Such analyses can be easily extended for genome-wide methylation analysis in health and disease.

Conserved domains and SINE diversity during animal evolution.

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Luchetti, Andrea; Mantovani, Barbara

2013-10-01

Eukaryotic genomes harbour a number of mobile genetic elements (MGEs); moving from one genomic location to another, they are known to impact on the host genome. Short interspersed elements (SINEs) are well-represented, non-autonomous retroelements and they are likely the most diversified MGEs. In some instances, sequence domains conserved across unrelated SINEs have been identified; remarkably, one of these, called Nin, has been conserved since the Radiata-Bilateria splitting. Here we report on two new domains: Inv, derived from Nin, identified in insects and in deuterostomes, and Pln, restricted to polyneopteran insects. The identification of Inv and Pln sequences allowed us to retrieve new SINEs, two in insects and one in a hemichordate. The diverse structural combination of the different domains in different SINE families, during metazoan evolution, offers a clearer view of SINE diversity and their frequent de novo emergence through module exchange, possibly underlying the high evolutionary success of SINEs. © 2013 Elsevier Inc. All rights reserved.

Genome-wide identification of conserved microRNA and their response to drought stress in Dongxiang wild rice (Oryza rufipogon Griff.).

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Zhang, Fantao; Luo, Xiangdong; Zhou, Yi; Xie, Jiankun

2016-04-01

To identify drought stress-responsive conserved microRNA (miRNA) from Dongxiang wild rice (Oryza rufipogon Griff., DXWR) on a genome-wide scale, high-throughput sequencing technology was used to sequence libraries of DXWR samples, treated with and without drought stress. 505 conserved miRNAs corresponding to 215 families were identified. 17 were significantly down-regulated and 16 were up-regulated under drought stress. Stem-loop qRT-PCR revealed the same expression patterns as high-throughput sequencing, suggesting the accuracy of the sequencing result was high. Potential target genes of the drought-responsive miRNA were predicted to be involved in diverse biological processes. Furthermore, 16 miRNA families were first identified to be involved in drought stress response from plants. These results present a comprehensive view of the conserved miRNA and their expression patterns under drought stress for DXWR, which will provide valuable information and sequence resources for future basis studies.

The sequence, structure and evolutionary features of HOTAIR in mammals

Science.gov (United States)

2011-01-01

Background An increasing number of long noncoding RNAs (lncRNAs) have been identified recently. Different from all the others that function in cis to regulate local gene expression, the newly identified HOTAIR is located between HoxC11 and HoxC12 in the human genome and regulates HoxD expression in multiple tissues. Like the well-characterised lncRNA Xist, HOTAIR binds to polycomb proteins to methylate histones at multiple HoxD loci, but unlike Xist, many details of its structure and function, as well as the trans regulation, remain unclear. Moreover, HOTAIR is involved in the aberrant regulation of gene expression in cancer. Results To identify conserved domains in HOTAIR and study the phylogenetic distribution of this lncRNA, we searched the genomes of 10 mammalian and 3 non-mammalian vertebrates for matches to its 6 exons and the two conserved domains within the 1800 bp exon6 using Infernal. There was just one high-scoring hit for each mammal, but many low-scoring hits were found in both mammals and non-mammalian vertebrates. These hits and their flanking genes in four placental mammals and platypus were examined to determine whether HOTAIR contained elements shared by other lncRNAs. Several of the hits were within unknown transcripts or ncRNAs, many were within introns of, or antisense to, protein-coding genes, and conservation of the flanking genes was observed only between human and chimpanzee. Phylogenetic analysis revealed discrete evolutionary dynamics for orthologous sequences of HOTAIR exons. Exon1 at the 5' end and a domain in exon6 near the 3' end, which contain domains that bind to multiple proteins, have evolved faster in primates than in other mammals. Structures were predicted for exon1, two domains of exon6 and the full HOTAIR sequence. The sequence and structure of two fragments, in exon1 and the domain B of exon6 respectively, were identified to robustly occur in predicted structures of exon1, domain B of exon6 and the full HOTAIR in mammals

Characteristics of the Lotus japonicus gene repertoire deduced from large-scale expressed sequence tag (EST) analysis.

Science.gov (United States)

Asamizu, Erika; Nakamura, Yasukazu; Sato, Shusei; Tabata, Satoshi

2004-02-01

To perform a comprehensive analysis of genes expressed in a model legume, Lotus japonicus, a total of 74472 3'-end expressed sequence tags (EST) were generated from cDNA libraries produced from six different organs. Clustering of sequences was performed with an identity criterion of 95% for 50 bases, and a total of 20457 non-redundant sequences, 8503 contigs and 11954 singletons were generated. EST sequence coverage was analyzed by using the annotated L. japonicus genomic sequence and 1093 of the 1889 predicted protein-encoding genes (57.9%) were hit by the EST sequence(s). Gene content was compared to several plant species. Among the 8503 contigs, 471 were identified as sequences conserved only in leguminous species and these included several disease resistance-related genes. This suggested that in legumes, these genes may have evolved specifically to resist pathogen attack. The rate of gene sequence divergence was assessed by comparing similarity level and functional category based on the Gene Ontology (GO) annotation of Arabidopsis genes. This revealed that genes encoding ribosomal proteins, as well as those related to translation, photosynthesis, and cellular structure were more abundantly represented in the highly conserved class, and that genes encoding transcription factors and receptor protein kinases were abundantly represented in the less conserved class. To make the sequence information and the cDNA clones available to the research community, a Web database with useful services was created at http://www.kazusa.or.jp/en/plant/lotus/EST/.

Conservation of Tcrg-V5 and limited allelic sequence polymorphism of the other Tcrg-V genes used by mouse tissue-specific gd-T lymphocytes

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Roger, T.; Morisset, J.; Seman, M. [Universite Denis Diderot, Paris (France)

1996-12-31

The mouse Tcrg locus comprises seven Tcrg-V, four Tcrg-J, and four Tcrg-C segments which generate only six major types of functional g chains, Vg7-, Vg4-, Vg6-, or Vg5-Jg1-Cg1, Vg2-Jg2-Cg2, and Vg1-Jg4-Cg4. A complete analysis of restriction fragment length polymorphism (RFLP) of the Tcrg locus in wild and inbred mice suggested its relative conservation compared to other loci of the immunoglobulin (Ig) gene family. Three haplotypes have been characterized in laboratory mice: gA, gB, and gC, represented by BALB/c, DBA/2, and AKR prototypes. Tcr-gA and -gC haplotypes are highly related. By contrast, Tcr-gB, likely inherited from Asian mouse subspecies, appeared very different by RFLP analysis. Yet only partial sequence data have been reported on gA and gB Tcrg-V genes. Here, the complete sequence of all Tcrg-V genes of the two haplotypes is described. 16 refs., 1 fig.

CLONING AND SEQUENCING OF PGIP FROM ‘JIN SERIES’ ALMOND (PRUNUS DULCIS

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Yuhu Han

2015-12-01

Full Text Available Specific primers synthesized according to conservative regions of polygalacturonase inhibiting protein (PGIP gene were used to amplify Prunus Dulcis genomic DNA by polymerase-chain reaction (PCR. Six bands (pgip1, pgip2, pgip3, pgip4, pgip5 and pgip6 of genes were obtained and cloned into PBS-T vector. According to the length of bands, 717bp, 864bp, 796bp were A1 (pgip1, pgip2, pgip3, A2 (pgip4, A4 (pgip5, pgip6, respectively. DNA sequences showed that the fragments taken together were the gene encoding PGIP. A2 and A3 contained two exons interrupted by one intron, which has GT-AG sequence. Its DNA and amino acid sequences were highly homologies to those from Prunus Persica; Prunus Salicina; Prunus Americana; Prunus Mume, respectively. A conserved lencinerial fragment exists in the derived protein sequence.

Conservation and divergence of ADAM family proteins in the Xenopus genome

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Shah Anoop

2010-07-01

Full Text Available Abstract Background Members of the disintegrin metalloproteinase (ADAM family play important roles in cellular and developmental processes through their functions as proteases and/or binding partners for other proteins. The amphibian Xenopus has long been used as a model for early vertebrate development, but genome-wide analyses for large gene families were not possible until the recent completion of the X. tropicalis genome sequence and the availability of large scale expression sequence tag (EST databases. In this study we carried out a systematic analysis of the X. tropicalis genome and uncovered several interesting features of ADAM genes in this species. Results Based on the X. tropicalis genome sequence and EST databases, we identified Xenopus orthologues of mammalian ADAMs and obtained full-length cDNA clones for these genes. The deduced protein sequences, synteny and exon-intron boundaries are conserved between most human and X. tropicalis orthologues. The alternative splicing patterns of certain Xenopus ADAM genes, such as adams 22 and 28, are similar to those of their mammalian orthologues. However, we were unable to identify an orthologue for ADAM7 or 8. The Xenopus orthologue of ADAM15, an active metalloproteinase in mammals, does not contain the conserved zinc-binding motif and is hence considered proteolytically inactive. We also found evidence for gain of ADAM genes in Xenopus as compared to other species. There is a homologue of ADAM10 in Xenopus that is missing in most mammals. Furthermore, a single scaffold of X. tropicalis genome contains four genes encoding ADAM28 homologues, suggesting genome duplication in this region. Conclusions Our genome-wide analysis of ADAM genes in X. tropicalis revealed both conservation and evolutionary divergence of these genes in this amphibian species. On the one hand, all ADAMs implicated in normal development and health in other species are conserved in X. tropicalis. On the other hand, some

Using genomic information to conserve genetic diversity in livestock

NARCIS (Netherlands)

Eynard, Sonia E.

2018-01-01

Concern about the status of livestock breeds and their conservation has increased as selection and small population sizes caused loss of genetic diversity. Meanwhile, dense SNP chips and whole genome sequences (WGS) became available, providing opportunities to accurately quantify the impact of

Computational identification of developmental enhancers:conservation and function of transcription factor binding-site clustersin drosophila melanogaster and drosophila psedoobscura

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Berman, Benjamin P.; Pfeiffer, Barret D.; Laverty, Todd R.; Salzberg, Steven L.; Rubin, Gerald M.; Eisen, Michael B.; Celniker, SusanE.

2004-08-06

The identification of sequences that control transcription in metazoans is a major goal of genome analysis. In a previous study, we demonstrated that searching for clusters of predicted transcription factor binding sites could discover active regulatory sequences, and identified 37 regions of the Drosophila melanogaster genome with high densities of predicted binding sites for five transcription factors involved in anterior-posterior embryonic patterning. Nine of these clusters overlapped known enhancers. Here, we report the results of in vivo functional analysis of 27 remaining clusters. We generated transgenic flies carrying each cluster attached to a basal promoter and reporter gene, and assayed embryos for reporter gene expression. Six clusters are enhancers of adjacent genes: giant, fushi tarazu, odd-skipped, nubbin, squeeze and pdm2; three drive expression in patterns unrelated to those of neighboring genes; the remaining 18 do not appear to have enhancer activity. We used the Drosophila pseudoobscura genome to compare patterns of evolution in and around the 15 positive and 18 false-positive predictions. Although conservation of primary sequence cannot distinguish true from false positives, conservation of binding-site clustering accurately discriminates functional binding-site clusters from those with no function. We incorporated conservation of binding-site clustering into a new genome-wide enhancer screen, and predict several hundred new regulatory sequences, including 85 adjacent to genes with embryonic patterns. Measuring conservation of sequence features closely linked to function--such as binding-site clustering--makes better use of comparative sequence data than commonly used methods that examine only sequence identity.

Characterizing leader sequences of CRISPR loci

DEFF Research Database (Denmark)

Alkhnbashi, Omer; Shah, Shiraz Ali; Garrett, Roger Antony

2016-01-01

The CRISPR-Cas system is an adaptive immune system in many archaea and bacteria, which provides resistance against invading genetic elements. The first phase of CRISPR-Cas immunity is called adaptation, in which small DNA fragments are excised from genetic elements and are inserted into a CRISPR...... array generally adjacent to its so called leader sequence at one end of the array. It has been shown that transcription initiation and adaptation signals of the CRISPR array are located within the leader. However, apart from promoters, there is very little knowledge of sequence or structural motifs...... sequences by focusing on the consensus repeat of the adjacent CRISPR array and weak upstream conservation signals. We applied our tool to the analysis of a comprehensive genomic database and identified several characteristic properties of leader sequences specific to archaea and bacteria, ranging from...

Genomic sequencing of Pleistocene cave bears

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Noonan, James P.; Hofreiter, Michael; Smith, Doug; Priest, JamesR.; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J. Chris; Paabo, Svante; Rubin, Edward M.

2005-04-01

Despite the information content of genomic DNA, ancient DNA studies to date have largely been limited to amplification of mitochondrial DNA due to technical hurdles such as contamination and degradation of ancient DNAs. In this study, we describe two metagenomic libraries constructed using unamplified DNA extracted from the bones of two 40,000-year-old extinct cave bears. Analysis of {approx}1 Mb of sequence from each library showed that, despite significant microbial contamination, 5.8 percent and 1.1 percent of clones in the libraries contain cave bear inserts, yielding 26,861 bp of cave bear genome sequence. Alignment of this sequence to the dog genome, the closest sequenced genome to cave bear in terms of evolutionary distance, revealed roughly the expected ratio of cave bear exons, repeats and conserved noncoding sequences. Only 0.04 percent of all clones sequenced were derived from contamination with modern human DNA. Comparison of cave bear with orthologous sequences from several modern bear species revealed the evolutionary relationship of these lineages. Using the metagenomic approach described here, we have recovered substantial quantities of mammalian genomic sequence more than twice as old as any previously reported, establishing the feasibility of ancient DNA genomic sequencing programs.

Novel nonphosphorylated peptides with conserved sequences selectively bind to Grb7 SH2 domain with affinity comparable to its phosphorylated ligand.

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Dan Zhang

Full Text Available The Grb7 (growth factor receptor-bound 7 protein, a member of the Grb7 protein family, is found to be highly expressed in such metastatic tumors as breast cancer, esophageal cancer, liver cancer, etc. The src-homology 2 (SH2 domain in the C-terminus is reported to be mainly involved in Grb7 signaling pathways. Using the random peptide library, we identified a series of Grb7 SH2 domain-binding nonphosphorylated peptides in the yeast two-hybrid system. These peptides have a conserved GIPT/K/N sequence at the N-terminus and G/WD/IP at the C-terminus, and the region between the N-and C-terminus contains fifteen amino acids enriched with serines, threonines and prolines. The association between the nonphosphorylated peptides and the Grb7 SH2 domain occurred in vitro and ex vivo. When competing for binding to the Grb7 SH2 domain in a complex, one synthesized nonphosphorylated ligand, containing the twenty-two amino acid-motif sequence, showed at least comparable affinity to the phosphorylated ligand of ErbB3 in vitro, and its overexpression inhibited the proliferation of SK-BR-3 cells. Such nonphosphorylated peptides may be useful for rational design of drugs targeted against cancers that express high levels of Grb7 protein.

Genomic sequence around butterfly wing development genes: annotation and comparative analysis.

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Inês C Conceição

Full Text Available BACKGROUND: Analysis of genomic sequence allows characterization of genome content and organization, and access beyond gene-coding regions for identification of functional elements. BAC libraries, where relatively large genomic regions are made readily available, are especially useful for species without a fully sequenced genome and can increase genomic coverage of phylogenetic and biological diversity. For example, no butterfly genome is yet available despite the unique genetic and biological properties of this group, such as diversified wing color patterns. The evolution and development of these patterns is being studied in a few target species, including Bicyclus anynana, where a whole-genome BAC library allows targeted access to large genomic regions. METHODOLOGY/PRINCIPAL FINDINGS: We characterize ∼1.3 Mb of genomic sequence around 11 selected genes expressed in B. anynana developing wings. Extensive manual curation of in silico predictions, also making use of a large dataset of expressed genes for this species, identified repetitive elements and protein coding sequence, and highlighted an expansion of Alcohol dehydrogenase genes. Comparative analysis with orthologous regions of the lepidopteran reference genome allowed assessment of conservation of fine-scale synteny (with detection of new inversions and translocations and of DNA sequence (with detection of high levels of conservation of non-coding regions around some, but not all, developmental genes. CONCLUSIONS: The general properties and organization of the available B. anynana genomic sequence are similar to the lepidopteran reference, despite the more than 140 MY divergence. Our results lay the groundwork for further studies of new interesting findings in relation to both coding and non-coding sequence: 1 the Alcohol dehydrogenase expansion with higher similarity between the five tandemly-repeated B. anynana paralogs than with the corresponding B. mori orthologs, and 2 the high

Evolutionary conservation of essential and highly expressed genes in Pseudomonas aeruginosa

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Scharfe Maren

2010-04-01

Full Text Available Abstract Background The constant increase in development and spread of bacterial resistance to antibiotics poses a serious threat to human health. New sequencing technologies are now on the horizon that will yield massive increases in our capacity for DNA sequencing and will revolutionize the drug discovery process. Since essential genes are promising novel antibiotic targets, the prediction of gene essentiality based on genomic information has become a major focus. Results In this study we demonstrate that pooled sequencing is applicable for the analysis of sequence variations of strain collections with more than 10 individual isolates. Pooled sequencing of 36 clinical Pseudomonas aeruginosa isolates revealed that essential and highly expressed proteins evolve at lower rates, whereas extracellular proteins evolve at higher rates. We furthermore refined the list of experimentally essential P. aeruginosa genes, and identified 980 genes that show no sequence variation at all. Among the conserved nonessential genes we found several that are involved in regulation, motility and virulence, indicating that they represent factors of evolutionary importance for the lifestyle of a successful environmental bacterium and opportunistic pathogen. Conclusion The detailed analysis of a comprehensive set of P. aeruginosa genomes in this study clearly disclosed detailed information of the genomic makeup and revealed a large set of highly conserved genes that play an important role for the lifestyle of this microorganism. Sequencing strain collections enables for a detailed and extensive identification of sequence variations as potential bacterial adaptation processes, e.g., during the development of antibiotic resistance in the clinical setting and thus may be the basis to uncover putative targets for novel treatment strategies.

Whole-Genome de novo Sequencing Of Quail And Grey Partridge

DEFF Research Database (Denmark)

Holm, Lars-Erik; Panitz, Frank; Burt, Dave

2011-01-01

The development in sequencing methods has made it possible to perform whole genome de novo sequencing of species without large commercial interests. Within the EU-financed QUANTOMICS project (KBBE-2A-222664), we have performed de novo sequencing of quail (Coturnix coturnix) and grey partridge...... (Perdix perdix) on a Genome Analyzer GAII (Illumina) using paired-end sequencing. The amount of generated sequences amounts to 8 to 9 Gb for each species. The analysis and assembly of the generated sequences is ongoing. Access to the whole genome sequence from these two species will enable enhanced...... comparative studies towards the chicken genome and will aid in identifying evolutionarily conserved sequences within the Galliformes. The obtained sequences from quail and partridge represent a beginning of generating the whole genome sequence for these species. The continuation of establishing the genome...

Whole-Genome Sequencing and Variant Analysis of Human Papillomavirus 16 Infections.

Science.gov (United States)

van der Weele, Pascal; Meijer, Chris J L M; King, Audrey J

2017-10-01

Human papillomavirus (HPV) is a strongly conserved DNA virus, high-risk types of which can cause cervical cancer in persistent infections. The most common type found in HPV-attributable cancer is HPV16, which can be subdivided into four lineages (A to D) with different carcinogenic properties. Studies have shown HPV16 sequence diversity in different geographical areas, but only limited information is available regarding HPV16 diversity within a population, especially at the whole-genome level. We analyzed HPV16 major variant diversity and conservation in persistent infections and performed a single nucleotide polymorphism (SNP) comparison between persistent and clearing infections. Materials were obtained in the Netherlands from a cohort study with longitudinal follow-up for up to 3 years. Our analysis shows a remarkably large variant diversity in the population. Whole-genome sequences were obtained for 57 persistent and 59 clearing HPV16 infections, resulting in 109 unique variants. Interestingly, persistent infections were completely conserved through time. One reinfection event was identified where the initial and follow-up samples clustered differently. Non-A1/A2 variants seemed to clear preferentially ( P = 0.02). Our analysis shows that population-wide HPV16 sequence diversity is very large. In persistent infections, the HPV16 sequence was fully conserved. Sequencing can identify HPV16 reinfections, although occurrence is rare. SNP comparison identified no strongly acting effect of the viral genome affecting HPV16 infection clearance or persistence in up to 3 years of follow-up. These findings suggest the progression of an early HPV16 infection could be host related. IMPORTANCE Human papillomavirus 16 (HPV16) is the predominant type found in cervical cancer. Progression of initial infection to cervical cancer has been linked to sequence properties; however, knowledge of variants circulating in European populations, especially with longitudinal follow-up, is

Comparative analysis of the full genome sequence of European bat lyssavirus type 1 and type 2 with other lyssaviruses and evidence for a conserved transcription termination and polyadenylation motif in the G-L 3' non-translated region.

Science.gov (United States)

Marston, D A; McElhinney, L M; Johnson, N; Müller, T; Conzelmann, K K; Tordo, N; Fooks, A R

2007-04-01

We report the first full-length genomic sequences for European bat lyssavirus type-1 (EBLV-1) and type-2 (EBLV-2). The EBLV-1 genomic sequence was derived from a virus isolated from a serotine bat in Hamburg, Germany, in 1968 and the EBLV-2 sequence was derived from a virus isolate from a human case of rabies that occurred in Scotland in 2002. A long-distance PCR strategy was used to amplify the open reading frames (ORFs), followed by standard and modified RACE (rapid amplification of cDNA ends) techniques to amplify the 3' and 5' ends. The lengths of each complete viral genome for EBLV-1 and EBLV-2 were 11 966 and 11 930 base pairs, respectively, and follow the standard rhabdovirus genome organization of five viral proteins. Comparison with other lyssavirus sequences demonstrates variation in degrees of homology, with the genomic termini showing a high degree of complementarity. The nucleoprotein was the most conserved, both intra- and intergenotypically, followed by the polymerase (L), matrix and glyco- proteins, with the phosphoprotein being the most variable. In addition, we have shown that the two EBLVs utilize a conserved transcription termination and polyadenylation (TTP) motif, approximately 50 nt upstream of the L gene start codon. All available lyssavirus sequences to date, with the exception of Pasteur virus (PV) and PV-derived isolates, use the second TTP site. This observation may explain differences in pathogenicity between lyssavirus strains, dependent on the length of the untranslated region, which might affect transcriptional activity and RNA stability.

Comparative genome sequencing of drosophila pseudoobscura: Chromosomal, gene and cis-element evolution

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Richards, Stephen; Liu, Yue; Bettencourt, Brian R.; Hradecky, Pavel; Letovsky, Stan; Nielsen, Rasmus; Thornton, Kevin; Todd, Melissa J.; Chen, Rui; Meisel, Richard P.; Couronne, Olivier; Hua, Sujun; Smith, Mark A.; Bussemaker, Harmen J.; van Batenburg, Marinus F.; Howells, Sally L.; Scherer, Steven E.; Sodergren, Erica; Matthews, Beverly B.; Crosby, Madeline A.; Schroeder, Andrew J.; Ortiz-Barrientos, Daniel; Rives, Catherine M.; Metzker, Michael L.; Muzny, Donna M.; Scott, Graham; Steffen, David; Wheeler, David A.; Worley, Kim C.; Havlak, Paul; Durbin, K. James; Egan, Amy; Gill, Rachel; Hume, Jennifer; Morgan, Margaret B.; Miner, George; Hamilton, Cerissa; Huang, Yanmei; Waldron, Lenee; Verduzco, Daniel; Blankenburg, Kerstin P.; Dubchak, Inna; Noor, Mohamed A.F.; Anderson, Wyatt; White, Kevin P.; Clark, Andrew G.; Schaeffer, Stephen W.; Gelbart, William; Weinstock, George M.; Gibbs, Richard A.

2004-04-01

The genome sequence of a second fruit fly, D. pseudoobscura, presents an opportunity for comparative analysis of a primary model organism D. melanogaster. The vast majority of Drosophila genes have remained on the same arm, but within each arm gene order has been extensively reshuffled leading to the identification of approximately 1300 syntenic blocks. A repetitive sequence is found in the D. pseudoobscura genome at many junctions between adjacent syntenic blocks. Analysis of this novel repetitive element family suggests that recombination between offset elements may have given rise to many paracentric inversions, thereby contributing to the shuffling of gene order in the D. pseudoobscura lineage. Based on sequence similarity and synteny, 10,516 putative orthologs have been identified as a core gene set conserved over 35 My since divergence. Genes expressed in the testes had higher amino acid sequence divergence than the genome wide average consistent with the rapid evolution of sex-specific proteins. Cis-regulatory sequences are more conserved than control sequences between the species but the difference is slight, suggesting that the evolution of cis-regulatory elements is flexible. Overall, a picture of repeat mediated chromosomal rearrangement, and high co-adaptation of both male genes and cis-regulatory sequences emerges as important themes of genome divergence between these species of Drosophila.

Discovery of Conservation and Diversification of miR171 Genes by Phylogenetic Analysis based on Global Genomes

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Xudong Zhu

2015-07-01

Full Text Available The microRNA171 (miR171 family is widely distributed and highly conserved in a range of species and plays critical roles in regulating plant growth and development through repressing expression of ( transcription factors. However, information on the evolutionary conservation and functional diversification of the miRNA171 family members remains scanty. We reconstructed the phylogenetic relationships among miR171 precursor and mature sequences so as to investigate the extent and degree of evolutionary conservation of miR171 in (L. Heynh. (ath, grape ( L. (vvi, poplar ( Torr. & A.Gray ex Hook. (ptc, and rice ( L. (osa. Despite strong conservation of over 80%, some mature miR171 sequences, such as , and and , -, and -, have undergone critical sequence variation, leading to functional diversification, since they target non gene transcript(s. Phylogenetic analyses revealed a combination of old ancestral relationships and recent lineage-specific diversification in the miR171 family within the four model plants. The -regulatory motifs on the upstream promoter sequences of genes were highly divergent and shared some similar elements, indicating their possible contribution to the functional variation observed within the miR171 family. This study will buttress our understanding of the functional differentiation of miRNAs and the relationships of miRNA–target pairs based on the evolutionary history of genes.

DNA-binding proteins from marine bacteria expand the known sequence diversity of TALE-like repeats.

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de Lange, Orlando; Wolf, Christina; Thiel, Philipp; Krüger, Jens; Kleusch, Christian; Kohlbacher, Oliver; Lahaye, Thomas

2015-11-16

Transcription Activator-Like Effectors (TALEs) of Xanthomonas bacteria are programmable DNA binding proteins with unprecedented target specificity. Comparative studies into TALE repeat structure and function are hindered by the limited sequence variation among TALE repeats. More sequence-diverse TALE-like proteins are known from Ralstonia solanacearum (RipTALs) and Burkholderia rhizoxinica (Bats), but RipTAL and Bat repeats are conserved with those of TALEs around the DNA-binding residue. We study two novel marine-organism TALE-like proteins (MOrTL1 and MOrTL2), the first to date of non-terrestrial origin. We have assessed their DNA-binding properties and modelled repeat structures. We found that repeats from these proteins mediate sequence specific DNA binding conforming to the TALE code, despite low sequence similarity to TALE repeats, and with novel residues around the BSR. However, MOrTL1 repeats show greater sequence discriminating power than MOrTL2 repeats. Sequence alignments show that there are only three residues conserved between repeats of all TALE-like proteins including the two new additions. This conserved motif could prove useful as an identifier for future TALE-likes. Additionally, comparing MOrTL repeats with those of other TALE-likes suggests a common evolutionary origin for the TALEs, RipTALs and Bats. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution.

Science.gov (United States)

2004-12-09

We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken is a modern descendant of the dinosaurs and the first non-mammalian amniote to have its genome sequenced, the draft sequence of its genome--composed of approximately one billion base pairs of sequence and an estimated 20,000-23,000 genes--provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes. For example, the evolutionary distance between chicken and human provides high specificity in detecting functional elements, both non-coding and coding. Notably, many conserved non-coding sequences are far from genes and cannot be assigned to defined functional classes. In coding regions the evolutionary dynamics of protein domains and orthologous groups illustrate processes that distinguish the lineages leading to birds and mammals. The distinctive properties of avian microchromosomes, together with the inferred patterns of conserved synteny, provide additional insights into vertebrate chromosome architecture.

Structure of the conserved hypothetical protein MAL13P1.257 from Plasmodium falciparum

International Nuclear Information System (INIS)

Holmes, Margaret A.; Buckner, Frederick S.; Van Voorhis, Wesley C.; Mehlin, Christopher; Boni, Erica; Earnest, Thomas N.; DeTitta, George; Luft, Joseph; Lauricella, Angela; Anderson, Lori; Kalyuzhniy, Oleksandr; Zucker, Frank; Schoenfeld, Lori W.; Hol, Wim G. J.; Merritt, Ethan A.

2006-01-01

The crystal structure of a conserved hypothetical protein, MAL13P1.257 from P. falciparum, has been determined at 2.17 Å resolution. The structure represents a new protein fold and is the first structural representative for Pfam sequence family PF05907. The structure of a conserved hypothetical protein, PlasmoDB sequence MAL13P1.257 from Plasmodium falciparum, Pfam sequence family PF05907, has been determined as part of the structural genomics effort of the Structural Genomics of Pathogenic Protozoa consortium. The structure was determined by multiple-wavelength anomalous dispersion at 2.17 Å resolution. The structure is almost entirely β-sheet; it consists of 15 β-strands and one short 3 10 -helix and represents a new protein fold. The packing of the two monomers in the asymmetric unit indicates that the biological unit may be a dimer.

Role of an Absolutely Conserved Tryptophan Pair in the Extracellular Domain of Cys-Loop Receptors

DEFF Research Database (Denmark)

Braun, Nina; Lynagh, Timothy; Yu, Rilei

2016-01-01

Cys-loop receptors mediate fast synaptic transmission in the nervous system, and their dysfunction is associated with a number of diseases. While some sequence variability is essential to ensure specific recognition of a chemically diverse set of ligands, other parts of the underlying amino acid...... sequences show a high degree of conservation, possibly to preserve the overall structural fold across the protein family. In this study, we focus on the only two absolutely conserved residues across the Cys-loop receptor family, two Trp side chains in the WXD motif of Loop D and in the WXPD motif of Loop A...

A conserved segmental duplication within ELA.

Science.gov (United States)

Brinkmeyer-Langford, C L; Murphy, W J; Childers, C P; Skow, L C

2010-12-01

The assembled genomic sequence of the horse major histocompatibility complex (MHC) (equine lymphocyte antigen, ELA) is very similar to the homologous human HLA, with the notable exception of a large segmental duplication at the boundary of ELA class I and class III that is absent in HLA. The segmental duplication consists of a ∼ 710 kb region of at least 11 repeated blocks: 10 blocks each contain an MHC class I-like sequence and the helicase domain portion of a BAT1-like sequence, and the remaining unit contains the full-length BAT1 gene. Similar genomic features were found in other Perissodactyls, indicating an ancient origin, which is consistent with phylogenetic analyses. Reverse-transcriptase PCR (RT-PCR) of mRNA from peripheral white blood cells of healthy and chronically or acutely infected horses detected transcription from predicted open reading frames in several of the duplicated blocks. This duplication is not present in the sequenced MHCs of most other mammals, although a similar feature at the same relative position is present in the feline MHC (FLA). Striking sequence conservation throughout Perissodactyl evolution is consistent with a functional role for at least some of the genes included within this segmental duplication. © 2010 The Authors, Journal compilation © 2010 Stichting International Foundation for Animal Genetics.

Differential evolution-simulated annealing for multiple sequence alignment

Science.gov (United States)

Addawe, R. C.; Addawe, J. M.; Sueño, M. R. K.; Magadia, J. C.

2017-10-01

Multiple sequence alignments (MSA) are used in the analysis of molecular evolution and sequence structure relationships. In this paper, a hybrid algorithm, Differential Evolution - Simulated Annealing (DESA) is applied in optimizing multiple sequence alignments (MSAs) based on structural information, non-gaps percentage and totally conserved columns. DESA is a robust algorithm characterized by self-organization, mutation, crossover, and SA-like selection scheme of the strategy parameters. Here, the MSA problem is treated as a multi-objective optimization problem of the hybrid evolutionary algorithm, DESA. Thus, we name the algorithm as DESA-MSA. Simulated sequences and alignments were generated to evaluate the accuracy and efficiency of DESA-MSA using different indel sizes, sequence lengths, deletion rates and insertion rates. The proposed hybrid algorithm obtained acceptable solutions particularly for the MSA problem evaluated based on the three objectives.

Puzzling sequences: studying microbial genomes from 'Ötzi'

International Nuclear Information System (INIS)

Rattei, T.

2012-01-01

Ancient remains, and mummies in particular, are of central value for archaeological research. The Tyrolean iceman “Ötzi” was conserved in a glacier of the Ötztal Alps about 5000 years ago. Aside from morphological and phenotypical classification, the determination of DNA sequences and the subsequent genome analyses have been first applied to mitochondrial DNA and then been extended to genomic DNA. Typically also ancient microbial DNA is sequenced. These sequences allow the identification of pathogens as well as studying the evolution of microorganisms. The talk will explain the metagenomic aspects of the “Ötzi” genome project and discuss the first results. (author)

Similarity-based gene detection: using COGs to find evolutionarily-conserved ORFs.

Science.gov (United States)

Powell, Bradford C; Hutchison, Clyde A

2006-01-19

Experimental verification of gene products has not kept pace with the rapid growth of microbial sequence information. However, existing annotations of gene locations contain sufficient information to screen for probable errors. Furthermore, comparisons among genomes become more informative as more genomes are examined. We studied all open reading frames (ORFs) of at least 30 codons from the genomes of 27 sequenced bacterial strains. We grouped the potential peptide sequences encoded from the ORFs by forming Clusters of Orthologous Groups (COGs). We used this grouping in order to find homologous relationships that would not be distinguishable from noise when using simple BLAST searches. Although COG analysis was initially developed to group annotated genes, we applied it to the task of grouping anonymous DNA sequences that may encode proteins. "Mixed COGs" of ORFs (clusters in which some sequences correspond to annotated genes and some do not) are attractive targets when seeking errors of gene prediction. Examination of mixed COGs reveals some situations in which genes appear to have been missed in current annotations and a smaller number of regions that appear to have been annotated as gene loci erroneously. This technique can also be used to detect potential pseudogenes or sequencing errors. Our method uses an adjustable parameter for degree of conservation among the studied genomes (stringency). We detail results for one level of stringency at which we found 83 potential genes which had not previously been identified, 60 potential pseudogenes, and 7 sequences with existing gene annotations that are probably incorrect. Systematic study of sequence conservation offers a way to improve existing annotations by identifying potentially homologous regions where the annotation of the presence or absence of a gene is inconsistent among genomes.

Similarity-based gene detection: using COGs to find evolutionarily-conserved ORFs

Directory of Open Access Journals (Sweden)

Hutchison Clyde A

2006-01-01

Full Text Available Abstract Background Experimental verification of gene products has not kept pace with the rapid growth of microbial sequence information. However, existing annotations of gene locations contain sufficient information to screen for probable errors. Furthermore, comparisons among genomes become more informative as more genomes are examined. We studied all open reading frames (ORFs of at least 30 codons from the genomes of 27 sequenced bacterial strains. We grouped the potential peptide sequences encoded from the ORFs by forming Clusters of Orthologous Groups (COGs. We used this grouping in order to find homologous relationships that would not be distinguishable from noise when using simple BLAST searches. Although COG analysis was initially developed to group annotated genes, we applied it to the task of grouping anonymous DNA sequences that may encode proteins. Results "Mixed COGs" of ORFs (clusters in which some sequences correspond to annotated genes and some do not are attractive targets when seeking errors of gene predicion. Examination of mixed COGs reveals some situations in which genes appear to have been missed in current annotations and a smaller number of regions that appear to have been annotated as gene loci erroneously. This technique can also be used to detect potential pseudogenes or sequencing errors. Our method uses an adjustable parameter for degree of conservation among the studied genomes (stringency. We detail results for one level of stringency at which we found 83 potential genes which had not previously been identified, 60 potential pseudogenes, and 7 sequences with existing gene annotations that are probably incorrect. Conclusion Systematic study of sequence conservation offers a way to improve existing annotations by identifying potentially homologous regions where the annotation of the presence or absence of a gene is inconsistent among genomes.

Conservation of Three-Dimensional Helix-Loop-Helix Structure through the Vertebrate Lineage Reopens the Cold Case of Gonadotropin-Releasing Hormone-Associated Peptide.

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Pérez Sirkin, Daniela I; Lafont, Anne-Gaëlle; Kamech, Nédia; Somoza, Gustavo M; Vissio, Paula G; Dufour, Sylvie

2017-01-01

GnRH-associated peptide (GAP) is the C-terminal portion of the gonadotropin-releasing hormone (GnRH) preprohormone. Although it was reported in mammals that GAP may act as a prolactin-inhibiting factor and can be co-secreted with GnRH into the hypophyseal portal blood, GAP has been practically out of the research circuit for about 20 years. Comparative studies highlighted the low conservation of GAP primary amino acid sequences among vertebrates, contributing to consider that this peptide only participates in the folding or carrying process of GnRH. Considering that the three-dimensional (3D) structure of a protein may define its function, the aim of this study was to evaluate if GAP sequences and 3D structures are conserved in the vertebrate lineage. GAP sequences from various vertebrates were retrieved from databases. Analysis of primary amino acid sequence identity and similarity, molecular phylogeny, and prediction of 3D structures were performed. Amino acid sequence comparison and phylogeny analyses confirmed the large variation of GAP sequences throughout vertebrate radiation. In contrast, prediction of the 3D structure revealed a striking conservation of the 3D structure of GAP1 (GAP associated with the hypophysiotropic type 1 GnRH), despite low amino acid sequence conservation. This GAP1 peptide presented a typical helix-loop-helix (HLH) structure in all the vertebrate species analyzed. This HLH structure could also be predicted for GAP2 in some but not all vertebrate species and in none of the GAP3 analyzed. These results allowed us to infer that selective pressures have maintained GAP1 HLH structure throughout the vertebrate lineage. The conservation of the HLH motif, known to confer biological activity to various proteins, suggests that GAP1 peptides may exert some hypophysiotropic biological functions across vertebrate radiation.

Conservation of Three-Dimensional Helix-Loop-Helix Structure through the Vertebrate Lineage Reopens the Cold Case of Gonadotropin-Releasing Hormone-Associated Peptide

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Daniela I. Pérez Sirkin

2017-08-01

Full Text Available GnRH-associated peptide (GAP is the C-terminal portion of the gonadotropin-releasing hormone (GnRH preprohormone. Although it was reported in mammals that GAP may act as a prolactin-inhibiting factor and can be co-secreted with GnRH into the hypophyseal portal blood, GAP has been practically out of the research circuit for about 20 years. Comparative studies highlighted the low conservation of GAP primary amino acid sequences among vertebrates, contributing to consider that this peptide only participates in the folding or carrying process of GnRH. Considering that the three-dimensional (3D structure of a protein may define its function, the aim of this study was to evaluate if GAP sequences and 3D structures are conserved in the vertebrate lineage. GAP sequences from various vertebrates were retrieved from databases. Analysis of primary amino acid sequence identity and similarity, molecular phylogeny, and prediction of 3D structures were performed. Amino acid sequence comparison and phylogeny analyses confirmed the large variation of GAP sequences throughout vertebrate radiation. In contrast, prediction of the 3D structure revealed a striking conservation of the 3D structure of GAP1 (GAP associated with the hypophysiotropic type 1 GnRH, despite low amino acid sequence conservation. This GAP1 peptide presented a typical helix-loop-helix (HLH structure in all the vertebrate species analyzed. This HLH structure could also be predicted for GAP2 in some but not all vertebrate species and in none of the GAP3 analyzed. These results allowed us to infer that selective pressures have maintained GAP1 HLH structure throughout the vertebrate lineage. The conservation of the HLH motif, known to confer biological activity to various proteins, suggests that GAP1 peptides may exert some hypophysiotropic biological functions across vertebrate radiation.

Essentials of Conservation Biotechnology: A mini review

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Merlyn Keziah, S.; Subathra Devi, C.

2017-11-01

Equilibrium of biodiversity is essential for the maintenance of the ecosystem as they are interdependent on each other. The decline in biodiversity is a global problem and an inevitable threat to the mankind. Major threats include unsustainable exploitation, habitat destruction, fragmentation, transformation, genetic pollution, invasive exotic species and degradation. This review covers the management strategies of biotechnology which include sin situ, ex situ conservation, computerized taxonomic analysis through construction of phylogenetic trees, calculating genetic distance, prioritizing the group for conservation, digital preservation of biodiversities within the coding and decoding keys, molecular approaches to asses biodiversity like polymerase chain reaction, real time, randomly amplified polymorphic DNA, restriction fragment length polymorphism, amplified fragment length polymorphism, single sequence repeats, DNA finger printing, single nucleotide polymorphism, cryopreservation and vitrification.

DNA barcodes for ecology, evolution, and conservation.

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Kress, W John; García-Robledo, Carlos; Uriarte, Maria; Erickson, David L

2015-01-01

The use of DNA barcodes, which are short gene sequences taken from a standardized portion of the genome and used to identify species, is entering a new phase of application as more and more investigations employ these genetic markers to address questions relating to the ecology and evolution of natural systems. The suite of DNA barcode markers now applied to specific taxonomic groups of organisms are proving invaluable for understanding species boundaries, community ecology, functional trait evolution, trophic interactions, and the conservation of biodiversity. The application of next-generation sequencing (NGS) technology will greatly expand the versatility of DNA barcodes across the Tree of Life, habitats, and geographies as new methodologies are explored and developed. Published by Elsevier Ltd.

Conservation of the TRAPPII-specific subunits of a Ypt/Rab exchanger complex

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Yoo Eunice

2007-02-01

Full Text Available Abstract Background Ypt/Rab GTPases and their GEF activators regulate intra-cellular trafficking in all eukaryotic cells. In S. cerivisiae, the modular TRAPP complex acts as a GEF for the Golgi gatekeepers: Ypt1 and the functional pair Ypt31/32. While TRAPPI, which acts in early Golgi, is conserved from fungi to animals, not much is known about TRAPPII, which acts in late Golgi and consists of TRAPPI plus three additional subunits. Results Here, we show a phylogenetic analysis of the three TRAPPII-specific subunits. One copy of each of the two essential subunits, Trs120 and Trs130, is present in almost every fully sequenced eukaryotic genome. Moreover, the primary, as well as the predicted secondary, structure of the Trs120- and Trs130-related sequences are conserved from fungi to animals. The mammalian orthologs of Trs120 and Trs130, NIBP and TMEM1, respectively, are candidates for human disorders. Currently, NIBP is implicated in signaling, and TMEM1 is suggested to have trans-membrane domains (TMDs and to function as a membrane channel. However, we show here that the yeast Trs130 does not function as a trans-membrane protein, and the human TMEM1 does not contain putative TMDs. The non-essential subunit, Trs65, is conserved only among many fungi and some unicellular eukaryotes. Multiple alignment analysis of each TRAPPII-specific subunit revealed conserved domains that include highly conserved amino acids. Conclusion We suggest that the function of both NIBP and TMEM1 in the regulation of intra-cellular trafficking is conserved from yeast to man. The conserved domains and amino acids discovered here can be used for functional analysis that should help to resolve the differences in the assigned functions of these proteins in fungi and animals.

The complete amino acid sequence of human erythrocyte diphosphoglycerate mutase.

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Haggarty, N W; Dunbar, B; Fothergill, L A

1983-01-01

The complete amino acid sequence of human erythrocyte diphosphoglycerate mutase, comprising 239 residues, was determined. The sequence was deduced from the four cyanogen bromide fragments, and from the peptides derived from these fragments after digestion with a number of proteolytic enzymes. Comparison of this sequence with that of the yeast glycolytic enzyme, phosphoglycerate mutase, shows that these enzymes are 47% identical. Most, but not all, of the residues implicated as being important for the activity of the glycolytic mutase are conserved in the erythrocyte diphosphoglycerate mutase. PMID:6313356

Multiplexed microsatellite recovery using massively parallel sequencing

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Jennings, T.N.; Knaus, B.J.; Mullins, T.D.; Haig, S.M.; Cronn, R.C.

2011-01-01

Conservation and management of natural populations requires accurate and inexpensive genotyping methods. Traditional microsatellite, or simple sequence repeat (SSR), marker analysis remains a popular genotyping method because of the comparatively low cost of marker development, ease of analysis and high power of genotype discrimination. With the availability of massively parallel sequencing (MPS), it is now possible to sequence microsatellite-enriched genomic libraries in multiplex pools. To test this approach, we prepared seven microsatellite-enriched, barcoded genomic libraries from diverse taxa (two conifer trees, five birds) and sequenced these on one lane of the Illumina Genome Analyzer using paired-end 80-bp reads. In this experiment, we screened 6.1 million sequences and identified 356958 unique microreads that contained di- or trinucleotide microsatellites. Examination of four species shows that our conversion rate from raw sequences to polymorphic markers compares favourably to Sanger- and 454-based methods. The advantage of multiplexed MPS is that the staggering capacity of modern microread sequencing is spread across many libraries; this reduces sample preparation and sequencing costs to less than $400 (USD) per species. This price is sufficiently low that microsatellite libraries could be prepared and sequenced for all 1373 organisms listed as 'threatened' and 'endangered' in the United States for under $0.5M (USD).

The mitochondrial genome of the stingless bee Melipona bicolor (Hymenoptera, Apidae, Meliponini: sequence, gene organization and a unique tRNA translocation event conserved across the tribe Meliponini

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Daniela Silvestre

2008-01-01

Full Text Available At present a complete mtDNA sequence has been reported for only two hymenopterans, the Old World honey bee, Apis mellifera and the sawfly Perga condei. Among the bee group, the tribe Meliponini (stingless bees has some distinction due to its Pantropical distribution, great number of species and large importance as main pollinators in several ecosystems, including the Brazilian rain forest. However few molecular studies have been conducted on this group of bees and few sequence data from mitochondrial genomes have been described. In this project, we PCR amplified and sequenced 78% of the mitochondrial genome of the stingless bee Melipona bicolor (Apidae, Meliponini. The sequenced region contains all of the 13 mitochondrial protein-coding genes, 18 of 22 tRNA genes, and both rRNA genes (one of them was partially sequenced. We also report the genome organization (gene content and order, gene translation, genetic code, and other molecular features, such as base frequencies, codon usage, gene initiation and termination. We compare these characteristics of M. bicolor to those of the mitochondrial genome of A. mellifera and other insects. A highly biased A+T content is a typical characteristic of the A. mellifera mitochondrial genome and it was even more extreme in that of M. bicolor. Length and compositional differences between M. bicolor and A. mellifera genes were detected and the gene order was compared. Eleven tRNA gene translocations were observed between these two species. This latter finding was surprising, considering the taxonomic proximity of these two bee tribes. The tRNA Lys gene translocation was investigated within Meliponini and showed high conservation across the Pantropical range of the tribe.

Stem loop sequences specific to transposable element IS605 are found linked to lipoprotein genes in Borrelia plasmids.

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Nicholas Delihas

Full Text Available BACKGROUND: Plasmids of Borrelia species are dynamic structures that contain a large number of repetitive genes, gene fragments, and gene fusions. In addition, the transposable element IS605/200 family, as well as degenerate forms of this IS element, are prevalent. In Helicobacter pylori, flanking regions of the IS605 transposase gene contain sequences that fold into identical small stem loops. These function in transposition at the single-stranded DNA level. METHODOLOGY/PRINCIPAL FINDINGS: In work reported here, bioinformatics techniques were used to scan Borrelia plasmid genomes for IS605 transposable element specific stem loop sequences. Two variant stem loop motifs are found in the left and right flanking regions of the transposase gene. Both motifs appear to have dispersed in plasmid genomes and are found "free-standing" and phylogenetically conserved without the associated IS605 transposase gene or the adjacent flanking sequence. Importantly, IS605 specific stem loop sequences are also found at the 3' ends of lipoprotein genes (PFam12 and PFam60, however the left and right sequences appear to develop their own evolutionary patterns. The lipoprotein gene-linked left stem loop sequences maintain the IS605 stem loop motif in orthologs but only at the RNA level. These show mutations whereby variants fold into phylogenetically conserved RNA-type stem loops that contain the wobble non-Watson-Crick G-U base-pairing. The right flanking sequence is associated with the family lipoprotein-1 genes. A comparison of homologs shows that the IS605 stem loop motif rapidly dissipates, but a more elaborate secondary structure appears to develop in its place. CONCLUSIONS/SIGNIFICANCE: Stem loop sequences specific to the transposable element IS605 are present in plasmid regions devoid of a transposase gene and significantly, are found linked to lipoprotein genes in Borrelia plasmids. These sequences are evolutionarily conserved and/or structurally developed in

Conservation of Charge and Conservation of Current

OpenAIRE

Eisenberg, Bob

2016-01-01

Conservation of current and conservation of charge are nearly the same thing: when enough is known about charge movement, conservation of current can be derived from conservation of charge, in ideal dielectrics, for example. Conservation of current is enforced implicitly in ideal dielectrics by theories that conserve charge. But charge movement in real materials like semiconductors or ionic solutions is never ideal. We present an apparently universal derivation of conservation of current and ...

A structural study for the optimisation of functional motifs encoded in protein sequences

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Helmer-Citterich Manuela

2004-04-01

Full Text Available Abstract Background A large number of PROSITE patterns select false positives and/or miss known true positives. It is possible that – at least in some cases – the weak specificity and/or sensitivity of a pattern is due to the fact that one, or maybe more, functional and/or structural key residues are not represented in the pattern. Multiple sequence alignments are commonly used to build functional sequence patterns. If residues structurally conserved in proteins sharing a function cannot be aligned in a multiple sequence alignment, they are likely to be missed in a standard pattern construction procedure. Results Here we present a new procedure aimed at improving the sensitivity and/ or specificity of poorly-performing patterns. The procedure can be summarised as follows: 1. residues structurally conserved in different proteins, that are true positives for a pattern, are identified by means of a computational technique and by visual inspection. 2. the sequence positions of the structurally conserved residues falling outside the pattern are used to build extended sequence patterns. 3. the extended patterns are optimised on the SWISS-PROT database for their sensitivity and specificity. The method was applied to eight PROSITE patterns. Whenever structurally conserved residues are found in the surface region close to the pattern (seven out of eight cases, the addition of information inferred from structural analysis is shown to improve pattern selectivity and in some cases selectivity and sensitivity as well. In some of the cases considered the procedure allowed the identification of functionally interesting residues, whose biological role is also discussed. Conclusion Our method can be applied to any type of functional motif or pattern (not only PROSITE ones which is not able to select all and only the true positive hits and for which at least two true positive structures are available. The computational technique for the identification of

A Simple Predictive Enhancer Syntax for Hindbrain Patterning Is Conserved in Vertebrate Genomes.

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Joseph Grice

Full Text Available Determining the function of regulatory elements is fundamental for our understanding of development, disease and evolution. However, the sequence features that mediate these functions are often unclear and the prediction of tissue-specific expression patterns from sequence alone is non-trivial. Previous functional studies have demonstrated a link between PBX-HOX and MEIS/PREP binding interactions and hindbrain enhancer activity, but the defining grammar of these sites, if any exists, has remained elusive.Here, we identify a shared sequence signature (syntax within a heterogeneous set of conserved vertebrate hindbrain enhancers composed of spatially co-occurring PBX-HOX and MEIS/PREP transcription factor binding motifs. We use this syntax to accurately predict hindbrain enhancers in 89% of cases (67/75 predicted elements from a set of conserved non-coding elements (CNEs. Furthermore, mutagenesis of the sites abolishes activity or generates ectopic expression, demonstrating their requirement for segmentally restricted enhancer activity in the hindbrain. We refine and use our syntax to predict over 3,000 hindbrain enhancers across the human genome. These sequences tend to be located near developmental transcription factors and are enriched in known hindbrain activating elements, demonstrating the predictive power of this simple model.Our findings support the theory that hundreds of CNEs, and perhaps thousands of regions across the human genome, function to coordinate gene expression in the developing hindbrain. We speculate that deeply conserved sequences of this kind contributed to the co-option of new genes into the hindbrain gene regulatory network during early vertebrate evolution by linking patterns of hox expression to downstream genes involved in segmentation and patterning, and evolutionarily newer instances may have continued to contribute to lineage-specific elaboration of the hindbrain.

BLSSpeller: exhaustive comparative discovery of conserved cis-regulatory elements.

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De Witte, Dieter; Van de Velde, Jan; Decap, Dries; Van Bel, Michiel; Audenaert, Pieter; Demeester, Piet; Dhoedt, Bart; Vandepoele, Klaas; Fostier, Jan

2015-12-01

The accurate discovery and annotation of regulatory elements remains a challenging problem. The growing number of sequenced genomes creates new opportunities for comparative approaches to motif discovery. Putative binding sites are then considered to be functional if they are conserved in orthologous promoter sequences of multiple related species. Existing methods for comparative motif discovery usually rely on pregenerated multiple sequence alignments, which are difficult to obtain for more diverged species such as plants. As a consequence, misaligned regulatory elements often remain undetected. We present a novel algorithm that supports both alignment-free and alignment-based motif discovery in the promoter sequences of related species. Putative motifs are exhaustively enumerated as words over the IUPAC alphabet and screened for conservation using the branch length score. Additionally, a confidence score is established in a genome-wide fashion. In order to take advantage of a cloud computing infrastructure, the MapReduce programming model is adopted. The method is applied to four monocotyledon plant species and it is shown that high-scoring motifs are significantly enriched for open chromatin regions in Oryza sativa and for transcription factor binding sites inferred through protein-binding microarrays in O.sativa and Zea mays. Furthermore, the method is shown to recover experimentally profiled ga2ox1-like KN1 binding sites in Z.mays. BLSSpeller was written in Java. Source code and manual are available at http://bioinformatics.intec.ugent.be/blsspeller Klaas.Vandepoele@psb.vib-ugent.be or jan.fostier@intec.ugent.be. Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

Identification of multiple distinct Snf2 subfamilies with conserved structural motifs.

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Flaus, Andrew; Martin, David M A; Barton, Geoffrey J; Owen-Hughes, Tom

2006-01-01

The Snf2 family of helicase-related proteins includes the catalytic subunits of ATP-dependent chromatin remodelling complexes found in all eukaryotes. These act to regulate the structure and dynamic properties of chromatin and so influence a broad range of nuclear processes. We have exploited progress in genome sequencing to assemble a comprehensive catalogue of over 1300 Snf2 family members. Multiple sequence alignment of the helicase-related regions enables 24 distinct subfamilies to be identified, a considerable expansion over earlier surveys. Where information is known, there is a good correlation between biological or biochemical function and these assignments, suggesting Snf2 family motor domains are tuned for specific tasks. Scanning of complete genomes reveals all eukaryotes contain members of multiple subfamilies, whereas they are less common and not ubiquitous in eubacteria or archaea. The large sample of Snf2 proteins enables additional distinguishing conserved sequence blocks within the helicase-like motor to be identified. The establishment of a phylogeny for Snf2 proteins provides an opportunity to make informed assignments of function, and the identification of conserved motifs provides a framework for understanding the mechanisms by which these proteins function.

Cytochrome b conservation between six camel breeds reared in Egypt

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Othman E. Othman

2017-06-01

It is concluded that cyto b sequence is highly conserved among all camel breeds reared in Egypt which belong to Camelus dromedaries in addition to the advantage of cyto b in differentiation between different livestock sources which enables it to widely use for the adulteration detection in mixed meat.

Combining specificity determining and conserved residues improves functional site prediction

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Gelfand Mikhail S

2009-06-01

Full Text Available Abstract Background Predicting the location of functionally important sites from protein sequence and/or structure is a long-standing problem in computational biology. Most current approaches make use of sequence conservation, assuming that amino acid residues conserved within a protein family are most likely to be functionally important. Most often these approaches do not consider many residues that act to define specific sub-functions within a family, or they make no distinction between residues important for function and those more relevant for maintaining structure (e.g. in the hydrophobic core. Many protein families bind and/or act on a variety of ligands, meaning that conserved residues often only bind a common ligand sub-structure or perform general catalytic activities. Results Here we present a novel method for functional site prediction based on identification of conserved positions, as well as those responsible for determining ligand specificity. We define Specificity-Determining Positions (SDPs, as those occupied by conserved residues within sub-groups of proteins in a family having a common specificity, but differ between groups, and are thus likely to account for specific recognition events. We benchmark the approach on enzyme families of known 3D structure with bound substrates, and find that in nearly all families residues predicted by SDPsite are in contact with the bound substrate, and that the addition of SDPs significantly improves functional site prediction accuracy. We apply SDPsite to various families of proteins containing known three-dimensional structures, but lacking clear functional annotations, and discusse several illustrative examples. Conclusion The results suggest a better means to predict functional details for the thousands of protein structures determined prior to a clear understanding of molecular function.

Bioactive endophytes warrant intensified exploration and conservation.

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Smith, Stephen A; Tank, David C; Boulanger, Lori-Ann; Bascom-Slack, Carol A; Eisenman, Kaury; Kingery, David; Babbs, Beatrice; Fenn, Kathleen; Greene, Joshua S; Hann, Bradley D; Keehner, Jocelyn; Kelley-Swift, Elizabeth G; Kembaiyan, Vivek; Lee, Sun Jin; Li, Puyao; Light, David Y; Lin, Emily H; Ma, Cong; Moore, Emily; Schorn, Michelle A; Vekhter, Daniel; Nunez, Percy V; Strobel, Gary A; Donoghue, Michael J; Strobel, Scott A

2008-08-25

A key argument in favor of conserving biodiversity is that as yet undiscovered biodiversity will yield products of great use to humans. However, the link between undiscovered biodiversity and useful products is largely conjectural. Here we provide direct evidence from bioassays of endophytes isolated from tropical plants and bioinformatic analyses that novel biology will indeed yield novel chemistry of potential value. We isolated and cultured 135 endophytic fungi and bacteria from plants collected in Peru. nrDNAs were compared to samples deposited in GenBank to ascertain the genetic novelty of cultured specimens. Ten endophytes were found to be as much as 15-30% different than any sequence in GenBank. Phylogenetic trees, using the most similar sequences in GenBank, were constructed for each endophyte to measure phylogenetic distance. Assays were also conducted on each cultured endophyte to record bioactivity, of which 65 were found to be bioactive. The novelty of our contribution is that we have combined bioinformatic analyses that document the diversity found in environmental samples with culturing and bioassays. These results highlight the hidden hyperdiversity of endophytic fungi and the urgent need to explore and conserve hidden microbial diversity. This study also showcases how undergraduate students can obtain data of great scientific significance.

Bioactive endophytes warrant intensified exploration and conservation.

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Stephen A Smith

2008-08-01

Full Text Available A key argument in favor of conserving biodiversity is that as yet undiscovered biodiversity will yield products of great use to humans. However, the link between undiscovered biodiversity and useful products is largely conjectural. Here we provide direct evidence from bioassays of endophytes isolated from tropical plants and bioinformatic analyses that novel biology will indeed yield novel chemistry of potential value.We isolated and cultured 135 endophytic fungi and bacteria from plants collected in Peru. nrDNAs were compared to samples deposited in GenBank to ascertain the genetic novelty of cultured specimens. Ten endophytes were found to be as much as 15-30% different than any sequence in GenBank. Phylogenetic trees, using the most similar sequences in GenBank, were constructed for each endophyte to measure phylogenetic distance. Assays were also conducted on each cultured endophyte to record bioactivity, of which 65 were found to be bioactive.The novelty of our contribution is that we have combined bioinformatic analyses that document the diversity found in environmental samples with culturing and bioassays. These results highlight the hidden hyperdiversity of endophytic fungi and the urgent need to explore and conserve hidden microbial diversity. This study also showcases how undergraduate students can obtain data of great scientific significance.

Conservation genetics and genomics of amphibians and reptiles.

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Shaffer, H Bradley; Gidiş, Müge; McCartney-Melstad, Evan; Neal, Kevin M; Oyamaguchi, Hilton M; Tellez, Marisa; Toffelmier, Erin M

2015-01-01

Amphibians and reptiles as a group are often secretive, reach their greatest diversity often in remote tropical regions, and contain some of the most endangered groups of organisms on earth. Particularly in the past decade, genetics and genomics have been instrumental in the conservation biology of these cryptic vertebrates, enabling work ranging from the identification of populations subject to trade and exploitation, to the identification of cryptic lineages harboring critical genetic variation, to the analysis of genes controlling key life history traits. In this review, we highlight some of the most important ways that genetic analyses have brought new insights to the conservation of amphibians and reptiles. Although genomics has only recently emerged as part of this conservation tool kit, several large-scale data sources, including full genomes, expressed sequence tags, and transcriptomes, are providing new opportunities to identify key genes, quantify landscape effects, and manage captive breeding stocks of at-risk species.

Gene family size conservation is a good indicator of evolutionary rates.

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Chen, Feng-Chi; Chen, Chiuan-Jung; Li, Wen-Hsiung; Chuang, Trees-Juen

2010-08-01

The evolution of duplicate genes has been a topic of broad interest. Here, we propose that the conservation of gene family size is a good indicator of the rate of sequence evolution and some other biological properties. By comparing the human-chimpanzee-macaque orthologous gene families with and without family size conservation, we demonstrate that genes with family size conservation evolve more slowly than those without family size conservation. Our results further demonstrate that both family expansion and contraction events may accelerate gene evolution, resulting in elevated evolutionary rates in the genes without family size conservation. In addition, we show that the duplicate genes with family size conservation evolve significantly more slowly than those without family size conservation. Interestingly, the median evolutionary rate of singletons falls in between those of the above two types of duplicate gene families. Our results thus suggest that the controversy on whether duplicate genes evolve more slowly than singletons can be resolved when family size conservation is taken into consideration. Furthermore, we also observe that duplicate genes with family size conservation have the highest level of gene expression/expression breadth, the highest proportion of essential genes, and the lowest gene compactness, followed by singletons and then by duplicate genes without family size conservation. Such a trend accords well with our observations of evolutionary rates. Our results thus point to the importance of family size conservation in the evolution of duplicate genes.

Identification of putative regulatory upstream ORFs in the yeast genome using heuristics and evolutionary conservation

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Bilsland Elizabeth

2007-08-01

Full Text Available Abstract Background The translational efficiency of an mRNA can be modulated by upstream open reading frames (uORFs present in certain genes. A uORF can attenuate translation of the main ORF by interfering with translational reinitiation at the main start codon. uORFs also occur by chance in the genome, in which case they do not have a regulatory role. Since the sequence determinants for functional uORFs are not understood, it is difficult to discriminate functional from spurious uORFs by sequence analysis. Results We have used comparative genomics to identify novel uORFs in yeast with a high likelihood of having a translational regulatory role. We examined uORFs, previously shown to play a role in regulation of translation in Saccharomyces cerevisiae, for evolutionary conservation within seven Saccharomyces species. Inspection of the set of conserved uORFs yielded the following three characteristics useful for discrimination of functional from spurious uORFs: a length between 4 and 6 codons, a distance from the start of the main ORF between 50 and 150 nucleotides, and finally a lack of overlap with, and clear separation from, neighbouring uORFs. These derived rules are inherently associated with uORFs with properties similar to the GCN4 locus, and may not detect most uORFs of other types. uORFs with high scores based on these rules showed a much higher evolutionary conservation than randomly selected uORFs. In a genome-wide scan in S. cerevisiae, we found 34 conserved uORFs from 32 genes that we predict to be functional; subsequent analysis showed the majority of these to be located within transcripts. A total of 252 genes were found containing conserved uORFs with properties indicative of a functional role; all but 7 are novel. Functional content analysis of this set identified an overrepresentation of genes involved in transcriptional control and development. Conclusion Evolutionary conservation of uORFs in yeasts can be traced up to 100

Genes involved in complex adaptive processes tend to have highly conserved upstream regions in mammalian genomes

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Kohane Isaac

2005-11-01

Full Text Available Abstract Background Recent advances in genome sequencing suggest a remarkable conservation in gene content of mammalian organisms. The similarity in gene repertoire present in different organisms has increased interest in studying regulatory mechanisms of gene expression aimed at elucidating the differences in phenotypes. In particular, a proximal promoter region contains a large number of regulatory elements that control the expression of its downstream gene. Although many studies have focused on identification of these elements, a broader picture on the complexity of transcriptional regulation of different biological processes has not been addressed in mammals. The regulatory complexity may strongly correlate with gene function, as different evolutionary forces must act on the regulatory systems under different biological conditions. We investigate this hypothesis by comparing the conservation of promoters upstream of genes classified in different functional categories. Results By conducting a rank correlation analysis between functional annotation and upstream sequence alignment scores obtained by human-mouse and human-dog comparison, we found a significantly greater conservation of the upstream sequence of genes involved in development, cell communication, neural functions and signaling processes than those involved in more basic processes shared with unicellular organisms such as metabolism and ribosomal function. This observation persists after controlling for G+C content. Considering conservation as a functional signature, we hypothesize a higher density of cis-regulatory elements upstream of genes participating in complex and adaptive processes. Conclusion We identified a class of functions that are associated with either high or low promoter conservation in mammals. We detected a significant tendency that points to complex and adaptive processes were associated with higher promoter conservation, despite the fact that they have emerged

A Bioinformatic Pipeline for Monitoring of the Mutational Stability of Viral Drug Targets with Deep-Sequencing Technology.

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Kravatsky, Yuri; Chechetkin, Vladimir; Fedoseeva, Daria; Gorbacheva, Maria; Kravatskaya, Galina; Kretova, Olga; Tchurikov, Nickolai

2017-11-23

The efficient development of antiviral drugs, including efficient antiviral small interfering RNAs (siRNAs), requires continuous monitoring of the strict correspondence between a drug and the related highly variable viral DNA/RNA target(s). Deep sequencing is able to provide an assessment of both the general target conservation and the frequency of particular mutations in the different target sites. The aim of this study was to develop a reliable bioinformatic pipeline for the analysis of millions of short, deep sequencing reads corresponding to selected highly variable viral sequences that are drug target(s). The suggested bioinformatic pipeline combines the available programs and the ad hoc scripts based on an original algorithm of the search for the conserved targets in the deep sequencing data. We also present the statistical criteria for the threshold of reliable mutation detection and for the assessment of variations between corresponding data sets. These criteria are robust against the possible sequencing errors in the reads. As an example, the bioinformatic pipeline is applied to the study of the conservation of RNA interference (RNAi) targets in human immunodeficiency virus 1 (HIV-1) subtype A. The developed pipeline is freely available to download at the website http://virmut.eimb.ru/. Brief comments and comparisons between VirMut and other pipelines are also presented.

Amino acid sequence analysis of the annexin super-gene family of proteins.

Science.gov (United States)

Barton, G J; Newman, R H; Freemont, P S; Crumpton, M J

1991-06-15

The annexins are a widespread family of calcium-dependent membrane-binding proteins. No common function has been identified for the family and, until recently, no crystallographic data existed for an annexin. In this paper we draw together 22 available annexin sequences consisting of 88 similar repeat units, and apply the techniques of multiple sequence alignment, pattern matching, secondary structure prediction and conservation analysis to the characterisation of the molecules. The analysis clearly shows that the repeats cluster into four distinct families and that greatest variation occurs within the repeat 3 units. Multiple alignment of the 88 repeats shows amino acids with conserved physicochemical properties at 22 positions, with only Gly at position 23 being absolutely conserved in all repeats. Secondary structure prediction techniques identify five conserved helices in each repeat unit and patterns of conserved hydrophobic amino acids are consistent with one face of a helix packing against the protein core in predicted helices a, c, d, e. Helix b is generally hydrophobic in all repeats, but contains a striking pattern of repeat-specific residue conservation at position 31, with Arg in repeats 4 and Glu in repeats 2, but unconserved amino acids in repeats 1 and 3. This suggests repeats 2 and 4 may interact via a buried saltbridge. The loop between predicted helices a and b of repeat 3 shows features distinct from the equivalent loop in repeats 1, 2 and 4, suggesting an important structural and/or functional role for this region. No compelling evidence emerges from this study for uteroglobin and the annexins sharing similar tertiary structures, or for uteroglobin representing a derivative of a primordial one-repeat structure that underwent duplication to give the present day annexins. The analyses performed in this paper are re-evaluated in the Appendix, in the light of the recently published X-ray structure for human annexin V. The structure confirms most of

Survey sequencing and comparative analysis of the elephant shark (Callorhinchus milii genome.

Directory of Open Access Journals (Sweden)

Byrappa Venkatesh

2007-04-01

Full Text Available Owing to their phylogenetic position, cartilaginous fishes (sharks, rays, skates, and chimaeras provide a critical reference for our understanding of vertebrate genome evolution. The relatively small genome of the elephant shark, Callorhinchus milii, a chimaera, makes it an attractive model cartilaginous fish genome for whole-genome sequencing and comparative analysis. Here, the authors describe survey sequencing (1.4x coverage and comparative analysis of the elephant shark genome, one of the first cartilaginous fish genomes to be sequenced to this depth. Repetitive sequences, represented mainly by a novel family of short interspersed element-like and long interspersed element-like sequences, account for about 28% of the elephant shark genome. Fragments of approximately 15,000 elephant shark genes reveal specific examples of genes that have been lost differentially during the evolution of tetrapod and teleost fish lineages. Interestingly, the degree of conserved synteny and conserved sequences between the human and elephant shark genomes are higher than that between human and teleost fish genomes. Elephant shark contains putative four Hox clusters indicating that, unlike teleost fish genomes, the elephant shark genome has not experienced an additional whole-genome duplication. These findings underscore the importance of the elephant shark as a critical reference vertebrate genome for comparative analysis of the human and other vertebrate genomes. This study also demonstrates that a survey-sequencing approach can be applied productively for comparative analysis of distantly related vertebrate genomes.

PknB remains an essential and a conserved target for drug development in susceptible and MDR strains of M. Tuberculosis.

Science.gov (United States)

Gupta, Anamika; Pal, Sudhir K; Pandey, Divya; Fakir, Najneen A; Rathod, Sunita; Sinha, Dhiraj; SivaKumar, S; Sinha, Pallavi; Periera, Mycal; Balgam, Shilpa; Sekar, Gomathi; UmaDevi, K R; Anupurba, Shampa; Nema, Vijay

2017-08-18

The Mycobacterium tuberculosis (M.tb) protein kinase B (PknB) which is now proved to be essential for the growth and survival of M.tb, is a transmembrane protein with a potential to be a good drug target. However it is not known if this target remains conserved in otherwise resistant isolates from clinical origin. The present study describes the conservation analysis of sequences covering the inhibitor binding domain of PknB to assess if it remains conserved in susceptible and resistant clinical strains of mycobacteria picked from three different geographical areas of India. A total of 116 isolates from North, South and West India were used in the study with a variable profile of their susceptibilities towards streptomycin, isoniazid, rifampicin, ethambutol and ofloxacin. Isolates were also spoligotyped in order to find if the conservation pattern of pknB gene remain consistent or differ with different spoligotypes. The impact of variation as found in the study was analyzed using Molecular dynamics simulations. The sequencing results with 115/116 isolates revealed the conserved nature of pknB sequences irrespective of their susceptibility status and spoligotypes. The only variation found was in one strains wherein pnkB sequence had G to A mutation at 664 position translating into a change of amino acid, Valine to Isoleucine. After analyzing the impact of this sequence variation using Molecular dynamics simulations, it was observed that the variation is causing no significant change in protein structure or the inhibitor binding. Hence, the study endorses that PknB is an ideal target for drug development and there is no pre-existing or induced resistance with respect to the sequences involved in inhibitor binding. Also if the mutation that we are reporting for the first time is found again in subsequent work, it should be checked with phenotypic profile before drawing the conclusion that it would affect the activity in any way. Bioinformatics analysis in our study

Mutations in the newly identified RAX regulatory sequence are not a frequent cause of micro/anophthalmia.

Science.gov (United States)

Chassaing, Nicolas; Vigouroux, Adeline; Calvas, Patrick

2009-06-01

Microphthalmia and anophthalmia are at the severe end of the spectrum of abnormalities in ocular development. A few genes (SOX2, OTX2, RAX, and CHX10) have been implicated in isolated micro/anophthalmia, but causative mutations of these genes explain less than a quarter of these developmental defects. A specifically conserved SOX2/OTX2-mediated RAX expression regulatory sequence has recently been identified. We postulated that mutations in this sequence could lead to micro/anophthalmia, and thus we performed molecular screening of this regulatory element in patients suffering from micro/anophthalmia. Fifty-one patients suffering from nonsyndromic microphthalmia (n = 40) or anophthalmia (n = 11) were included in this study after negative molecular screening for SOX2, OTX2, RAX, and CHX10 mutations. Mutation screening of the RAX regulatory sequence was performed by direct sequencing for these patients. No mutations were identified in the highly conserved RAX regulatory sequence in any of the 51 patients. Mutations in the newly identified RAX regulatory sequence do not represent a frequent cause of nonsyndromic micro/anophthalmia.

Sequence-based Screening for Rare Enzymes: New Insights into the World of AMDases Reveal a Conserved Motif and 58 Novel Enzymes Clustering in Eight Distinct Families.

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Janine Maimanakos

2016-08-01

Full Text Available Arylmalonate-Decarboxylases (AMDases, EC 4.1.1.76 are very rare and mostly underexplored enzymes. Currently only four known and biochemically characterized representatives exist. However, their ability to decarboxylate α-disubstituted malonic acid derivatives to optically pure products without cofactors makes them attractive and promising candidates for the use as biocatalysts in industrial processes. Until now, AMDases could not be separated from other members of the aspartate/glutamate racemase superfamily based on their gene sequences. Within this work, a search algorithm was developed that enables a reliable prediction of AMDase activity for potential candidates. Based on specific sequence patterns and screening methods 58 novel AMDase candidate genes could be identified in this work. Thereby, AMDases with the conserved sequence pattern of Bordetella bronchiseptica’s prototype appeared to be limited to the classes of Alpha-, Beta- and Gammaproteobacteria. Amino acid homologies and comparison of gene surrounding sequences enabled the classification of eight enzyme clusters. Particularly striking is the accumulation of genes coding for different transporters of the TTT family, TRAP transporters and ABC transporters as well as genes coding for mandelate racemases/muconate lactonizing enzymes that might be involved in substrate uptake or degradation of AMDase products. Further, three novel AMDases were characterized which showed a high enantiomeric excess (>99% of the (R-enantiomer of flurbiprofen. These are the recombinant AmdA and AmdV from Variovorax sp. strains HH01 and HH02, originated from soil, and AmdP from Polymorphum gilvum found by a data base search. Altogether our findings give new insights into the class of AMDases and reveal many previously unknown enzyme candidates with high potential for bioindustrial processes.

The Highly Conserved Proline at Position 438 in Pseudorabies Virus gH Is Important for Regulation of Membrane Fusion

OpenAIRE

Schröter, Christina; Klupp, Barbara G.; Fuchs, Walter; Gerhard, Marika; Backovic, Marija; Rey, Felix A.; Mettenleiter, Thomas C.

2014-01-01

Membrane fusion in herpesviruses requires viral glycoproteins (g) gB and gH/gL. While gB is considered the actual fusion protein but is nonfusogenic per se, the function of gH/gL remains enigmatic. Crystal structures for different gH homologs are strikingly similar despite only moderate amino acid sequence conservation. A highly conserved sequence motif comprises the residues serine-proline-cysteine corresponding to positions 437 to 439 in pseudorabies virus (PrV) gH. The PrV-gH structure sho...

Conserved residues and their role in the structure, function, and stability of acyl-coenzyme A binding protein

DEFF Research Database (Denmark)

Kragelund, B B; Poulsen, K; Andersen, K V

1999-01-01

In the family of acyl-coenzyme A binding proteins, a subset of 26 sequence sites are identical in all eukaryotes and conserved throughout evolution of the eukaryotic kingdoms. In the context of the bovine protein, the importance of these 26 sequence positions for structure, function, stability...

Inverse statistical physics of protein sequences: a key issues review.

Science.gov (United States)

Cocco, Simona; Feinauer, Christoph; Figliuzzi, Matteo; Monasson, Rémi; Weigt, Martin

2018-03-01

In the course of evolution, proteins undergo important changes in their amino acid sequences, while their three-dimensional folded structure and their biological function remain remarkably conserved. Thanks to modern sequencing techniques, sequence data accumulate at unprecedented pace. This provides large sets of so-called homologous, i.e. evolutionarily related protein sequences, to which methods of inverse statistical physics can be applied. Using sequence data as the basis for the inference of Boltzmann distributions from samples of microscopic configurations or observables, it is possible to extract information about evolutionary constraints and thus protein function and structure. Here we give an overview over some biologically important questions, and how statistical-mechanics inspired modeling approaches can help to answer them. Finally, we discuss some open questions, which we expect to be addressed over the next years.

Myxobolus cerebralis internal transcribed spacer 1 (ITS-1) sequences support recent spread of the parasite to North America and within Europe

Science.gov (United States)

Whipps, Christopher M.; El-Matbouli, M.; Hedrick, R.P.; Blazer, V.; Kent, M.L.

2004-01-01

Molecular approaches for resolving relationships among the Myxozoa have relied mainly on small subunit (SSU) ribosomal DNA (rDNA) sequence analysis. This region of the gene is generally used for higher phylogenetic studies, and the conservative nature of this gene may make it inadequate for intraspecific comparisons. Previous intraspecific studies of Myxobolus cerebralis based on molecular analyses reported that the sequence of SSU rDNA and the internal transcribed spacer (ITS) were highly conserved in representatives of the parasite from North America and Europe. Considering that the ITS is usually a more variable region than the SSU, we reanalyzed available sequences on GenBank and obtained sequences from other M. cerebralis representatives from the states of California and West Virginia in the USA and from Germany and Russia. With the exception of 7 base pairs, most of the sequence designated as ITS-1 in GenBank was a highly conserved portion of the rDNA near the 3-prime end of the SSU region. Nonetheless, the additional ITS-1 sequences obtained from the available geographic representatives were well conserved. It is unlikely that we would have observed virtually identical ITS-1 sequences between European and American M. cerebralis samples had it spread naturally over time, particularly when compared to the variation seen between isolates of another myxozoan (Kudoa thyrsites) that has most likely spread naturally. These data further support the hypothesis that the current distribution of M. cerebralis in North America is a result of recent introductions followed by dispersal via anthropogenic means, largely through the stocking of infected trout for sport fishing.

Sequence Capture versus Restriction Site Associated DNA Sequencing for Shallow Systematics.

Science.gov (United States)

Harvey, Michael G; Smith, Brian Tilston; Glenn, Travis C; Faircloth, Brant C; Brumfield, Robb T

2016-09-01

Sequence capture and restriction site associated DNA sequencing (RAD-Seq) are two genomic enrichment strategies for applying next-generation sequencing technologies to systematics studies. At shallow timescales, such as within species, RAD-Seq has been widely adopted among researchers, although there has been little discussion of the potential limitations and benefits of RAD-Seq and sequence capture. We discuss a series of issues that may impact the utility of sequence capture and RAD-Seq data for shallow systematics in non-model species. We review prior studies that used both methods, and investigate differences between the methods by re-analyzing existing RAD-Seq and sequence capture data sets from a Neotropical bird (Xenops minutus). We suggest that the strengths of RAD-Seq data sets for shallow systematics are the wide dispersion of markers across the genome, the relative ease and cost of laboratory work, the deep coverage and read overlap at recovered loci, and the high overall information that results. Sequence capture's benefits include flexibility and repeatability in the genomic regions targeted, success using low-quality samples, more straightforward read orthology assessment, and higher per-locus information content. The utility of a method in systematics, however, rests not only on its performance within a study, but on the comparability of data sets and inferences with those of prior work. In RAD-Seq data sets, comparability is compromised by low overlap of orthologous markers across species and the sensitivity of genetic diversity in a data set to an interaction between the level of natural heterozygosity in the samples examined and the parameters used for orthology assessment. In contrast, sequence capture of conserved genomic regions permits interrogation of the same loci across divergent species, which is preferable for maintaining comparability among data sets and studies for the purpose of drawing general conclusions about the impact of

Community standards for genomic resources, genetic conservation, and data integration

Science.gov (United States)

Jill Wegrzyn; Meg Staton; Emily Grau; Richard Cronn; C. Dana Nelson

2017-01-01

Genetics and genomics are increasingly important in forestry management and conservation. Next generation sequencing can increase analytical power, but still relies on building on the structure of previously acquired data. Data standards and data sharing allow the community to maximize the analytical power of high throughput genomics data. The landscape of incomplete...

Structural basis for sequence-specific recognition of DNA by TAL effectors

KAUST Repository

Deng, Dong; Yan, Chuangye; Pan, Xiaojing; Mahfouz, Magdy M.; Wang, Jiawei; Zhu, Jiankang; Shi, Yi Gong; Yan, Nieng

2012-01-01

TAL (transcription activator-like) effectors, secreted by phytopathogenic bacteria, recognize host DNA sequences through a central domain of tandem repeats. Each repeat comprises 33 to 35 conserved amino acids and targets a specific base pair

Investigation of genome sequences within the family Pasteurellaceae

DEFF Research Database (Denmark)

Angen, Øystein; Ussery, David

Introduction The bacterial genome sequences are now available for an increasing number of strains within the family Pasteurellaceae. At present, 24 Pasteurellaceae genomes are publicly available through internet databases, and another 40 genomes are being sequenced. This investigation will describe...... the core genome for both the family Pasteurellaceae and for the species Haemophilus influenzae. Methods Twenty genome sequences from the following species were included: Haemophilus influenzae (11 strains), Haemophilus ducreyi (1 strain), Histophilus somni (2 strains), Haemophilus parasuis (1 strain......), Actinobacillus pleuropneumoniae (2 strains), Actinobacillus succinogenes (1 strain), Mannheimia succiniciproducens (1 strain), and Pasteurella multocida (1 strain). The predicted proteins for each genome were BLASTed against each other, and a set of conserved core gene families was determined as described...

Conservation of nucleotide sequences for molecular diagnosis of Middle East respiratory syndrome coronavirus, 2015

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Yuki Furuse

2015-11-01

Full Text Available Infection due to the Middle East respiratory syndrome coronavirus (MERS-CoV is widespread. The present study was performed to assess the protocols used for the molecular diagnosis of MERS-CoV by analyzing the nucleotide sequences of viruses detected between 2012 and 2015, including sequences from the large outbreak in eastern Asia in 2015. Although the diagnostic protocols were established only 2 years ago, mismatches between the sequences of primers/probes and viruses were found for several of the assays. Such mismatches could lead to a lower sensitivity of the assay, thereby leading to false-negative diagnosis. A slight modification in the primer design is suggested. Protocols for the molecular diagnosis of viral infections should be reviewed regularly after they are established, particularly for viruses that pose a great threat to public health such as MERS-CoV.

MODexplorer: an integrated tool for exploring protein sequence, structure and function relationships.

KAUST Repository

Kosinski, Jan; Barbato, Alessandro; Tramontano, Anna

2013-01-01

SUMMARY: MODexplorer is an integrated tool aimed at exploring the sequence, structural and functional diversity in protein families useful in homology modeling and in analyzing protein families in general. It takes as input either the sequence or the structure of a protein and provides alignments with its homologs along with a variety of structural and functional annotations through an interactive interface. The annotations include sequence conservation, similarity scores, ligand-, DNA- and RNA-binding sites, secondary structure, disorder, crystallographic structure resolution and quality scores of models implied by the alignments to the homologs of known structure. MODexplorer can be used to analyze sequence and structural conservation among the structures of similar proteins, to find structures of homologs solved in different conformational state or with different ligands and to transfer functional annotations. Furthermore, if the structure of the query is not known, MODexplorer can be used to select the modeling templates taking all this information into account and to build a comparative model. AVAILABILITY AND IMPLEMENTATION: Freely available on the web at http://modorama.biocomputing.it/modexplorer. Website implemented in HTML and JavaScript with all major browsers supported. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

MODexplorer: an integrated tool for exploring protein sequence, structure and function relationships.

KAUST Repository

Kosinski, Jan

2013-02-08

SUMMARY: MODexplorer is an integrated tool aimed at exploring the sequence, structural and functional diversity in protein families useful in homology modeling and in analyzing protein families in general. It takes as input either the sequence or the structure of a protein and provides alignments with its homologs along with a variety of structural and functional annotations through an interactive interface. The annotations include sequence conservation, similarity scores, ligand-, DNA- and RNA-binding sites, secondary structure, disorder, crystallographic structure resolution and quality scores of models implied by the alignments to the homologs of known structure. MODexplorer can be used to analyze sequence and structural conservation among the structures of similar proteins, to find structures of homologs solved in different conformational state or with different ligands and to transfer functional annotations. Furthermore, if the structure of the query is not known, MODexplorer can be used to select the modeling templates taking all this information into account and to build a comparative model. AVAILABILITY AND IMPLEMENTATION: Freely available on the web at http://modorama.biocomputing.it/modexplorer. Website implemented in HTML and JavaScript with all major browsers supported. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Does the evolutionary conservation of microsatellite loci imply function?

Energy Technology Data Exchange (ETDEWEB)

Shriver, M.D.; Deka, R.; Ferrell, R.E. [Univ. of Pittsburgh, PA (United States)] [and others

1994-09-01

Microsatellites are highly polymorphic tandem arrays of short (1-6 bp) sequence motifs which have been found widely distributed in the genomes of all eukaryotes. We have analyzed allele frequency data on 16 microsatellite loci typed in the great apes (human, chimp, orangutan, and gorilla). The majority of these loci (13) were isolated from human genomic libraries; three were cloned from chimpanzee genomic DNA. Most of these loci are not only present in all apes species, but are polymorphic with comparable levels of heterozygosity and have alleles which overlap in size. The extent of divergence of allele frequencies among these four species were studies using the stepwise-weighted genetic distance (Dsw), which was previously shown to conform to linearity with evolutionary time since divergence for loci where mutations exist in a stepwise fashion. The phylogenetic tree of the great apes constructed from this distance matrix was consistent with the expected topology, with a high bootstrap confidence (82%) for the human/chimp clade. However, the allele frequency distributions of these species are 10 times more similar to each other than expected when they were calibrated with a conservative estimate of the time since separation of humans and the apes. These results are in agreement with sequence-based surveys of microsatellites which have demonstrated that they are highly (90%) conserved over short periods of evolutionary time (< 10 million years) and moderately (30%) conserved over long periods of evolutionary time (> 60-80 million years). This evolutionary conservation has prompted some authors to speculate that there are functional constraints on microsatellite loci. In contrast, the presence of directional bias of mutations with constraints and/or selection against aberrant sized alleles can explain these results.

Plastome Sequence Determination and Comparative Analysis for Members of the Lolium-Festuca Grass Species Complex

Science.gov (United States)

Hand, Melanie L.; Spangenberg, German C.; Forster, John W.; Cogan, Noel O. I.

2013-01-01

Chloroplast genome sequences are of broad significance in plant biology, due to frequent use in molecular phylogenetics, comparative genomics, population genetics, and genetic modification studies. The present study used a second-generation sequencing approach to determine and assemble the plastid genomes (plastomes) of four representatives from the agriculturally important Lolium-Festuca species complex of pasture grasses (Lolium multiflorum, Festuca pratensis, Festuca altissima, and Festuca ovina). Total cellular DNA was extracted from either roots or leaves, was sequenced, and the output was filtered for plastome-related reads. A comparison between sources revealed fewer plastome-related reads from root-derived template but an increase in incidental bacterium-derived sequences. Plastome assembly and annotation indicated high levels of sequence identity and a conserved organization and gene content between species. However, frequent deletions within the F. ovina plastome appeared to contribute to a smaller plastid genome size. Comparative analysis with complete plastome sequences from other members of the Poaceae confirmed conservation of most grass-specific features. Detailed analysis of the rbcL–psaI intergenic region, however, revealed a “hot-spot” of variation characterized by independent deletion events. The evolutionary implications of this observation are discussed. The complete plastome sequences are anticipated to provide the basis for potential organelle-specific genetic modification of pasture grasses. PMID:23550121

Discovery of cis-elements between sorghum and rice using co-expression and evolutionary conservation

Directory of Open Access Journals (Sweden)

Haberer Georg

2009-06-01

Full Text Available Abstract Background The spatiotemporal regulation of gene expression largely depends on the presence and absence of cis-regulatory sites in the promoter. In the economically highly important grass family, our knowledge of transcription factor binding sites and transcriptional networks is still very limited. With the completion of the sorghum genome and the available rice genome sequence, comparative promoter analyses now allow genome-scale detection of conserved cis-elements. Results In this study, we identified thousands of phylogenetic footprints conserved between orthologous rice and sorghum upstream regions that are supported by co-expression information derived from three different rice expression data sets. In a complementary approach, cis-motifs were discovered by their highly conserved co-occurrence in syntenic promoter pairs. Sequence conservation and matches to known plant motifs support our findings. Expression similarities of gene pairs positively correlate with the number of motifs that are shared by gene pairs and corroborate the importance of similar promoter architectures for concerted regulation. This strongly suggests that these motifs function in the regulation of transcript levels in rice and, presumably also in sorghum. Conclusion Our work provides the first large-scale collection of cis-elements for rice and sorghum and can serve as a paradigm for cis-element analysis through comparative genomics in grasses in general.

Phylogenomics of Phrynosomatid Lizards: Conflicting Signals from Sequence Capture versus Restriction Site Associated DNA Sequencing

Science.gov (United States)

Leaché, Adam D.; Chavez, Andreas S.; Jones, Leonard N.; Grummer, Jared A.; Gottscho, Andrew D.; Linkem, Charles W.

2015-01-01

Sequence capture and restriction site associated DNA sequencing (RADseq) are popular methods for obtaining large numbers of loci for phylogenetic analysis. These methods are typically used to collect data at different evolutionary timescales; sequence capture is primarily used for obtaining conserved loci, whereas RADseq is designed for discovering single nucleotide polymorphisms (SNPs) suitable for population genetic or phylogeographic analyses. Phylogenetic questions that span both “recent” and “deep” timescales could benefit from either type of data, but studies that directly compare the two approaches are lacking. We compared phylogenies estimated from sequence capture and double digest RADseq (ddRADseq) data for North American phrynosomatid lizards, a species-rich and diverse group containing nine genera that began diversifying approximately 55 Ma. Sequence capture resulted in 584 loci that provided a consistent and strong phylogeny using concatenation and species tree inference. However, the phylogeny estimated from the ddRADseq data was sensitive to the bioinformatics steps used for determining homology, detecting paralogs, and filtering missing data. The topological conflicts among the SNP trees were not restricted to any particular timescale, but instead were associated with short internal branches. Species tree analysis of the largest SNP assembly, which also included the most missing data, supported a topology that matched the sequence capture tree. This preferred phylogeny provides strong support for the paraphyly of the earless lizard genera Holbrookia and Cophosaurus, suggesting that the earless morphology either evolved twice or evolved once and was subsequently lost in Callisaurus. PMID:25663487

The identification and functional annotation of RNA structures conserved in vertebrates.

Science.gov (United States)

Seemann, Stefan E; Mirza, Aashiq H; Hansen, Claus; Bang-Berthelsen, Claus H; Garde, Christian; Christensen-Dalsgaard, Mikkel; Torarinsson, Elfar; Yao, Zizhen; Workman, Christopher T; Pociot, Flemming; Nielsen, Henrik; Tommerup, Niels; Ruzzo, Walter L; Gorodkin, Jan

2017-08-01

Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization, and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for conserved RNA structures (CRSs), leveraging structure-based, rather than sequence-based, alignments. After careful correction for sequence identity and GC content, we predict ∼516,000 human genomic regions containing CRSs. We find that a substantial fraction of human-mouse CRS regions (1) colocalize consistently with binding sites of the same RNA binding proteins (RBPs) or (2) are transcribed in corresponding tissues. Additionally, a CaptureSeq experiment revealed expression of many of our CRS regions in human fetal brain, including 662 novel ones. For selected human and mouse candidate pairs, qRT-PCR and in vitro RNA structure probing supported both shared expression and shared structure despite low abundance and low sequence identity. About 30,000 CRS regions are located near coding or long noncoding RNA genes or within enhancers. Structured (CRS overlapping) enhancer RNAs and extended 3' ends have significantly increased expression levels over their nonstructured counterparts. Our findings of transcribed uncharacterized regulatory regions that contain CRSs support their RNA-mediated functionality. © 2017 Seemann et al.; Published by Cold Spring Harbor Laboratory Press.

Genetic diversity in breonadia salicina based on intra-species sequence variation of chloroplast dna spacer sequence

International Nuclear Information System (INIS)

Qurainy, F.A.; Gaafar, A.R.Z.

2014-01-01

Assessment and knowledge of the genetic diversity and variation within and between populations of rare and endangered plants is very important for effective conservation. Intergenic spacer sequences variation of psbA-trnH locus of chloroplast genome was assessed within Breonadia salicina (Rubiaceae), a critically endangered and endemic plant species to South western part of Kingdom of Saudi Arabia. The obtained sequence data from 19 individuals in three populations revealed nine haplotypes. The aligned sequences obtained from the overall Saudi accessions extended to 355 bp, revealing nine haplotypes. A high level of haplotype diversity (Hd = 0.842) and low level of nucleotide diversity (Pi = 0.0058) were detected. Consistently, both hierarchical analysis of molecular variance (AMOVA) and constructed neighbor-joining tree indicated null genetic differentiation among populations. This level of differentiation between populations or between regions in psbA-trnH sequences may be due to effects of the abundance of ancestral haplotype sharing and the presence of private haplotypes fixed for each population. Furthermore, the results revealed almost the same level of genetic diversity in comparison with Yemeni accessions, in which Saudi accessions were sharing three haplotypes from the four haplotypes found in Yemeni accessions. (author)

A Bioinformatic Pipeline for Monitoring of the Mutational Stability of Viral Drug Targets with Deep-Sequencing Technology

Directory of Open Access Journals (Sweden)

Yuri Kravatsky

2017-11-01

Full Text Available The efficient development of antiviral drugs, including efficient antiviral small interfering RNAs (siRNAs, requires continuous monitoring of the strict correspondence between a drug and the related highly variable viral DNA/RNA target(s. Deep sequencing is able to provide an assessment of both the general target conservation and the frequency of particular mutations in the different target sites. The aim of this study was to develop a reliable bioinformatic pipeline for the analysis of millions of short, deep sequencing reads corresponding to selected highly variable viral sequences that are drug target(s. The suggested bioinformatic pipeline combines the available programs and the ad hoc scripts based on an original algorithm of the search for the conserved targets in the deep sequencing data. We also present the statistical criteria for the threshold of reliable mutation detection and for the assessment of variations between corresponding data sets. These criteria are robust against the possible sequencing errors in the reads. As an example, the bioinformatic pipeline is applied to the study of the conservation of RNA interference (RNAi targets in human immunodeficiency virus 1 (HIV-1 subtype A. The developed pipeline is freely available to download at the website http://virmut.eimb.ru/. Brief comments and comparisons between VirMut and other pipelines are also presented.

Two different groups of signal sequence in M-superfamily conotoxins.

Science.gov (United States)

Wang, Qi; Jiang, Hui; Han, Yu-Hong; Yuan, Duo-Duo; Chi, Cheng-Wu

2008-04-01

M-superfamily conotoxins can be divided into four branches (M-1, M-2, M-3 and M-4) according to the number of amino acid residues in the third Cys loop. In general, it is widely accepted that the conotoxin signal peptides of each superfamily are strictly conserved. Recently, we cloned six cDNAs of novel M-superfamily conotoxins from Conus leopardus, Conus marmoreus and Conus quercinus, belonging to either M-1 or M-3 branch. These conotoxins, judging from the putative peptide sequences deducted from cDNAs, are rich in acidic residues and share highly conserved signal and pro-peptide region. However, they are quite different from the reported conotoxins of M-2 and M-4 branches even in their signal peptides, which in general are considered highly conserved for each superfamily of conotoxins. The signal sequences of M-1 and M-3 conotoxins composed of 24 residues start with MLKMGVVL-, while those of M-2 and M-4 conotoxins composed of 25 residues start with MMSKLGVL-. It is another example that different types of signal peptides can exist within a superfamily besides the I-conotoxin superfamily. In addition to the different disulfide connectivity of M-1 conotoxins from that of M-4 or M-2 conotoxins, the sequence alignment, preferential Cys codon usage and phylogenetic tree analysis suggest that M-1 and M-3 conotoxins have much closer relationship, being different from the conotoxins of other two branches (M-4 and M-2) of M-superfamily.

Energy Conservation in Optical Fibers With Distributed Brick-Walls Filters

Science.gov (United States)

Garcia, Javier; Ghozlan, Hassan; Kramer, Gerhard

2018-05-01

A band-pass filtering scheme is proposed to mitigate spectral broadening and channel coupling in the Nonlinear Schr\\"odinger (NLS) fiber optic channel. The scheme is modeled by modifying the NLS Equation to include an attenuation profile with multiple brick-wall filters centered at different frequencies. It is shown that this brick-walls profile conserves the total in-band energy of the launch signal. Furthermore, energy fluctuations between the filtered channels are characterized, and conditions on the channel spacings are derived that ensure energy conservation in each channel. The maximum spectral efficiency of such a system is derived, and a constructive rule for achieving it using Sidon sequences is provided.

Conservation of the LexA repressor binding site in Deinococcus radiodurans

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Khan Feroz

2008-03-01

Full Text Available The LexA protein is a transcriptional repressor of the bacterial SOS DNA repair system, which comprises a set of DNA repair and cellular survival genes that are induced in response to DNA damage. Its varied DNA binding motifs have been characterized and reported in the Escherichia coli, Bacillus subtilis, rhizobia family members, marine magnetotactic bacterium, Salmonella typhimurium and recently in Mycobacterium tuberculosis and this motifs information has been used in our theoretical analysis to detect its novel regulated genes in radio-resistant Deinococcus radiodurans genome. This bacterium showed presence of SOS-box like consensus sequence in the upstream sequences of 3166 genes with >60% motif score similarity percentage (MSSP on both strands. Attempts to identify LexA-binding sites and the composition of the putative SOS regulon in D. radiodurans have been unsuccessful so far. To resolve the problem we performed theoretical analysis with modifications on reported data set of genes related to DNA repair (61 genes, stress response (145 genes and some unusual predicted operons (21 clusters. Expression of some of the predicted SOS-box regulated operon members then was examined through the previously reported microarray data which confirm the expression of only single predicted operon i.e. DRB0143 (AAA superfamily NTPase related to 5-methylcytosine specific restriction enzyme subunit McrB and DRB0144 (homolog of the McrC subunit of the McrBC restriction modification system. The methodology involved weight matrix construction through CONSENSUS algorithm using information of conserved upstream sequences of eight known genes including dinB, tagC, lexA, recA, uvrB, yneA of B. subtilis while lexA and recA of D. radiodurans through phylogenetic footprinting method and later detection of similar conserved SOS-box like LexA binding motifs through both RSAT & PoSSuMsearch programs. The resultant DNA consensus sequence had highly conserved 14 bp SOS

ChIP-seq Identification of Weakly Conserved Heart Enhancers

Energy Technology Data Exchange (ETDEWEB)

Blow, Matthew J.; McCulley, David J.; Li, Zirong; Zhang, Tao; Akiyama, Jennifer A.; Holt, Amy; Plajzer-Frick, Ingrid; Shoukry, Malak; Wright, Crystal; Chen, Feng; Afzal, Veena; Bristow, James; Ren, Bing; Black, Brian L.; Rubin, Edward M.; Visel, Axel; Pennacchio, Len A.

2010-07-01

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme non-coding sequence conservation successfully predicts enhancers active in many tissues, but fails to identify substantial numbers of heart enhancers. Here we used ChIP-seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over three thousand candidate heart enhancers genome-wide. Compared to other tissues studied at this time-point, most candidate heart enhancers are less deeply conserved in vertebrate evolution. Nevertheless, the testing of 130 candidate regions in a transgenic mouse assay revealed that most of them reproducibly function as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary constraint of embryonic enhancers can vary depending on tissue type.

An online conserved SSR discovery through cross-species comparison

Directory of Open Access Journals (Sweden)

Tun-Wen Pai

2009-02-01

Full Text Available Tun-Wen Pai1, Chien-Ming Chen1, Meng-Chang Hsiao1, Ronshan Cheng2, Wen-Shyong Tzou3, Chin-Hua Hu31Department of Computer Science and Engineering; 2Department of Aquaculture, 3Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan, Republic of ChinaAbstract: Simple sequence repeats (SSRs play important roles in gene regulation and genome evolution. Although there exist several online resources for SSR mining, most of them only extract general SSR patterns without providing functional information. Here, an online search tool, CG-SSR (Comparative Genomics SSR discovery, has been developed for discovering potential functional SSRs from vertebrate genomes through cross-species comparison. In addition to revealing SSR candidates in conserved regions among various species, it also combines accurate coordinate and functional genomics information. CG-SSR is the first comprehensive and efficient online tool for conserved SSR discovery.Keywords: microsatellites, genome, comparative genomics, functional SSR, gene ontology, conserved region

Dynamic Epigenetic Control of Highly Conserved Noncoding Elements

KAUST Repository

Seridi, Loqmane

2014-10-07

Background Many noncoding genomic loci have remained constant over long evolutionary periods, suggesting that they are exposed to strong selective pressures. The molecular functions of these elements have been partially elucidated, but the fundamental reason for their extreme conservation is still unknown. Results To gain new insights into the extreme selection of highly conserved noncoding elements (HCNEs), we used a systematic analysis of multi-omic data to study the epigenetic regulation of such elements during the development of Drosophila melanogaster. At the sequence level, HCNEs are GC-rich and have a characteristic oligomeric composition. They have higher levels of stable nucleosome occupancy than their flanking regions, and lower levels of mononucleosomes and H3.3, suggesting that these regions reside in compact chromatin. Furthermore, these regions showed remarkable modulations in histone modification and the expression levels of adjacent genes during development. Although HCNEs are primarily initiated late in replication, about 10% were related to early replication origins. Finally, HCNEs showed strong enrichment within lamina-associated domains. Conclusion HCNEs have distinct and protective sequence properties, undergo dynamic epigenetic regulation, and appear to be associated with the structural components of the chromatin, replication origins, and nuclear matrix. These observations indicate that such elements are likely to have essential cellular functions, and offer insights into their epigenetic properties.

Dynamic Epigenetic Control of Highly Conserved Noncoding Elements

KAUST Repository

Seridi, Loqmane; Ryu, Tae Woo; Ravasi, Timothy

2014-01-01

Background Many noncoding genomic loci have remained constant over long evolutionary periods, suggesting that they are exposed to strong selective pressures. The molecular functions of these elements have been partially elucidated, but the fundamental reason for their extreme conservation is still unknown. Results To gain new insights into the extreme selection of highly conserved noncoding elements (HCNEs), we used a systematic analysis of multi-omic data to study the epigenetic regulation of such elements during the development of Drosophila melanogaster. At the sequence level, HCNEs are GC-rich and have a characteristic oligomeric composition. They have higher levels of stable nucleosome occupancy than their flanking regions, and lower levels of mononucleosomes and H3.3, suggesting that these regions reside in compact chromatin. Furthermore, these regions showed remarkable modulations in histone modification and the expression levels of adjacent genes during development. Although HCNEs are primarily initiated late in replication, about 10% were related to early replication origins. Finally, HCNEs showed strong enrichment within lamina-associated domains. Conclusion HCNEs have distinct and protective sequence properties, undergo dynamic epigenetic regulation, and appear to be associated with the structural components of the chromatin, replication origins, and nuclear matrix. These observations indicate that such elements are likely to have essential cellular functions, and offer insights into their epigenetic properties.

Strong conservation of rhoptry-associated-protein-1 (RAP-1) locus organization and sequence among Babesia isolates infecting sheep from China (Babesia motasi-like phylogenetic group).

Science.gov (United States)

Niu, Qingli; Valentin, Charlotte; Bonsergent, Claire; Malandrin, Laurence

2014-12-01

Rhoptry-associated-protein 1 (RAP-1) is considered as a potential vaccine candidate due to its involvement in red blood cell invasion by parasites in the genus Babesia. We examined its value as a vaccine candidate by studying RAP-1 conservation in isolates of Babesia sp. BQ1 Ningxian, Babesia sp. Tianzhu and Babesia sp. Hebei, responsible for ovine babesiosis in different regions of China. The rap-1 locus in these isolates has very similar features to those described for Babesia sp. BQ1 Lintan, another Chinese isolate also in the B. motasi-like phylogenetic group, namely the presence of three types of rap-1 genes (rap-1a, rap-1b and rap-1c), multiple conserved rap-1b copies (5) interspaced with more or less variable rap-1a copies (6), and the 3' localization of one rap-1c. The isolates Babesia sp. Tianzhu, Babesia sp. BQ1 Lintan and Ningxian were almost identical (average nucleotide identity of 99.9%) over a putative locus of about 31 Kb, including the intergenic regions. Babesia sp. Hebei showed a similar locus organization but differed in the rap-1 locus sequence, for each gene and intergenic region, with an average nucleotide identity of 78%. Our results are in agreement with 18S rDNA phylogenetic studies performed on these isolates. However, in extremely closely related isolates the rap-1 locus seems more conserved (99.9%) than the 18S rDNA (98.7%), whereas in still closely related isolates the identities are much lower (78%) compared with the 18S rDNA (97.7%). The particularities of the rap-1 locus in terms of evolution, phylogeny, diagnosis and vaccine development are discussed. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Examining the Conservation of Kinks in Alpha Helices.

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Eleanor C Law

Full Text Available Kinks are a structural feature of alpha-helices and many are known to have functional roles. Kinks have previously tended to be defined in a binary fashion. In this paper we have deliberately moved towards defining them on a continuum, which given the unimodal distribution of kink angles is a better description. From this perspective, we examine the conservation of kinks in proteins. We find that kink angles are not generally a conserved property of homologs, pointing either to their not being functionally critical or to their function being related to conformational flexibility. In the latter case, the different structures of homologs are providing snapshots of different conformations. Sequence identity between homologous helices is informative in terms of kink conservation, but almost equally so is the sequence identity of residues in spatial proximity to the kink. In the specific case of proline, which is known to be prevalent in kinked helices, loss of a proline from a kinked helix often also results in the loss of a kink or reduction in its kink angle. We carried out a study of the seven transmembrane helices in the GPCR family and found that changes in kinks could be related both to subfamilies of GPCRs and also, in a particular subfamily, to the binding of agonists or antagonists. These results suggest conformational change upon receptor activation within the GPCR family. We also found correlation between kink angles in different helices, and the possibility of concerted motion could be investigated further by applying our method to molecular dynamics simulations. These observations reinforce the belief that helix kinks are key, functional, flexible points in structures.

Crystal structure of AFV3-109, a highly conserved protein from crenarchaeal viruses

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Quevillon-Cheruel Sophie

2007-01-01

Full Text Available Abstract The extraordinary morphologies of viruses infecting hyperthermophilic archaea clearly distinguish them from bacterial and eukaryotic viruses. Moreover, their genomes code for proteins that to a large extend have no related sequences in the extent databases. However, a small pool of genes is shared by overlapping subsets of these viruses, and the most conserved gene, exemplified by the ORF109 of the Acidianus Filamentous Virus 3, AFV3, is present on genomes of members of three viral familes, the Lipothrixviridae, Rudiviridae, and "Bicaudaviridae", as well as of the unclassified Sulfolobus Turreted Icosahedral Virus, STIV. We present here the crystal structure of the protein (Mr = 13.1 kD, 109 residues encoded by the AFV3 ORF 109 in two different crystal forms at 1.5 and 1.3 Å resolution. The structure of AFV3-109 is a five stranded β-sheet with loops on one side and three helices on the other. It forms a dimer adopting the shape of a cradle that encompasses the best conserved regions of the sequence. No protein with a related fold could be identified except for the ortholog from STIV1, whose structure was deposited at the Protein Data Bank. We could clearly identify a well bound glycerol inside the cradle, contacting exclusively totally conserved residues. This interaction was confirmed in solution by fluorescence titration. Although the function of AFV3-109 cannot be deduced directly from its structure, structural homology with the STIV1 protein, and the size and charge distribution of the cavity suggested it could interact with nucleic acids. Fluorescence quenching titrations also showed that AFV3-109 interacts with dsDNA. Genomic sequence analysis revealed bacterial homologs of AFV3-109 as a part of a putative previously unidentified prophage sequences in some Firmicutes.

Packaging of Mason-Pfizer monkey virus (MPMV) genomic RNA depends upon conserved long-range interactions (LRIs) between U5 and gag sequences.

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Kalloush, Rawan M; Vivet-Boudou, Valérie; Ali, Lizna M; Mustafa, Farah; Marquet, Roland; Rizvi, Tahir A

2016-06-01

MPMV has great potential for development as a vector for gene therapy. In this respect, precisely defining the sequences and structural motifs that are important for dimerization and packaging of its genomic RNA (gRNA) are of utmost importance. A distinguishing feature of the MPMV gRNA packaging signal is two phylogenetically conserved long-range interactions (LRIs) between U5 and gag complementary sequences, LRI-I and LRI-II. To test their biological significance in the MPMV life cycle, we introduced mutations into these structural motifs and tested their effects on MPMV gRNA packaging and propagation. Furthermore, we probed the structure of key mutants using SHAPE (selective 2'hydroxyl acylation analyzed by primer extension). Disrupting base-pairing of the LRIs affected gRNA packaging and propagation, demonstrating their significance to the MPMV life cycle. A double mutant restoring a heterologous LRI-I was fully functional, whereas a similar LRI-II mutant failed to restore gRNA packaging and propagation. These results demonstrate that while LRI-I acts at the structural level, maintaining base-pairing is not sufficient for LRI-II function. In addition, in vitro RNA dimerization assays indicated that the loss of RNA packaging in LRI mutants could not be attributed to the defects in dimerization. Our findings suggest that U5-gag LRIs play an important architectural role in maintaining the structure of the 5' region of the MPMV gRNA, expanding the crucial role of LRIs to the nonlentiviral group of retroviruses. © 2016 Kalloush et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Tandemly repeated sequence in 5'end of mtDNA control region of ...

African Journals Online (AJOL)

STORAGESEVER

2008-12-17

Dec 17, 2008 ... chain reaction (PCR). Japanese Spanish ... mainly covered general ecology and fishery biology. No study concerning the ... Conserved sequence blocks and the repeat units are indicated by boxes. performed using the exact ...

Comparative genome sequencing of Drosophila pseudoobscura: Chromosomal, gene, and cis-element evolution

DEFF Research Database (Denmark)

Richards, Stephen; Liu, Yue; Bettencourt, Brian R.

2005-01-01

years (Myr) since the pseudoobscura/melanogaster divergence. Genes expressed in the testes had higher amino acid sequence divergence than the genome-wide average, consistent with the rapid evolution of sex-specific proteins. Cis-regulatory sequences are more conserved than random and nearby sequences......We have sequenced the genome of a second Drosophila species, Drosophila pseudoobscura, and compared this to the genome sequence of Drosophila melanogaster, a primary model organism. Throughout evolution the vast majority of Drosophila genes have remained on the same chromosome arm, but within each...... between the species-but the difference is slight, suggesting that the evolution of cis-regulatory elements is flexible. Overall, a pattern of repeat-mediated chromosomal rearrangement, and high coadaptation of both male genes and cis-regulatory sequences emerges as important themes of genome divergence...

Genome sequencing of chimpanzee malaria parasites reveals possible pathways of adaptation to human hosts

KAUST Repository

Otto, Thomas D.

2014-09-09

Plasmodium falciparum causes most human malaria deaths, having prehistorically evolved from parasites of African Great Apes. Here we explore the genomic basis of P. falciparum adaptation to human hosts by fully sequencing the genome of the closely related chimpanzee parasite species P. reichenowi, and obtaining partial sequence data from a more distantly related chimpanzee parasite (P. gaboni). The close relationship between P. reichenowi and P. falciparum is emphasized by almost complete conservation of genomic synteny, but against this strikingly conserved background we observe major differences at loci involved in erythrocyte invasion. The organization of most virulence-associated multigene families, including the hypervariable var genes, is broadly conserved, but P. falciparum has a smaller subset of rif and stevor genes whose products are expressed on the infected erythrocyte surface. Genome-wide analysis identifies other loci under recent positive selection, but a limited number of changes at the host–parasite interface may have mediated host switching.

Seed storage protein gene promoters contain conserved DNA motifs in Brassicaceae, Fabaceae and Poaceae

Science.gov (United States)

Fauteux, François; Strömvik, Martina V

2009-01-01

Background Accurate computational identification of cis-regulatory motifs is difficult, particularly in eukaryotic promoters, which typically contain multiple short and degenerate DNA sequences bound by several interacting factors. Enrichment in combinations of rare motifs in the promoter sequence of functionally or evolutionarily related genes among several species is an indicator of conserved transcriptional regulatory mechanisms. This provides a basis for the computational identification of cis-regulatory motifs. Results We have used a discriminative seeding DNA motif discovery algorithm for an in-depth analysis of 54 seed storage protein (SSP) gene promoters from three plant families, namely Brassicaceae (mustards), Fabaceae (legumes) and Poaceae (grasses) using backgrounds based on complete sets of promoters from a representative species in each family, namely Arabidopsis (Arabidopsis thaliana (L.) Heynh.), soybean (Glycine max (L.) Merr.) and rice (Oryza sativa L.) respectively. We have identified three conserved motifs (two RY-like and one ACGT-like) in Brassicaceae and Fabaceae SSP gene promoters that are similar to experimentally characterized seed-specific cis-regulatory elements. Fabaceae SSP gene promoter sequences are also enriched in a novel, seed-specific E2Fb-like motif. Conserved motifs identified in Poaceae SSP gene promoters include a GCN4-like motif, two prolamin-box-like motifs and an Skn-1-like motif. Evidence of the presence of a variant of the TATA-box is found in the SSP gene promoters from the three plant families. Motifs discovered in SSP gene promoters were used to score whole-genome sets of promoters from Arabidopsis, soybean and rice. The highest-scoring promoters are associated with genes coding for different subunits or precursors of seed storage proteins. Conclusion Seed storage protein gene promoter motifs are conserved in diverse species, and different plant families are characterized by a distinct combination of conserved motifs

Seed storage protein gene promoters contain conserved DNA motifs in Brassicaceae, Fabaceae and Poaceae

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Fauteux François

2009-10-01

Full Text Available Abstract Background Accurate computational identification of cis-regulatory motifs is difficult, particularly in eukaryotic promoters, which typically contain multiple short and degenerate DNA sequences bound by several interacting factors. Enrichment in combinations of rare motifs in the promoter sequence of functionally or evolutionarily related genes among several species is an indicator of conserved transcriptional regulatory mechanisms. This provides a basis for the computational identification of cis-regulatory motifs. Results We have used a discriminative seeding DNA motif discovery algorithm for an in-depth analysis of 54 seed storage protein (SSP gene promoters from three plant families, namely Brassicaceae (mustards, Fabaceae (legumes and Poaceae (grasses using backgrounds based on complete sets of promoters from a representative species in each family, namely Arabidopsis (Arabidopsis thaliana (L. Heynh., soybean (Glycine max (L. Merr. and rice (Oryza sativa L. respectively. We have identified three conserved motifs (two RY-like and one ACGT-like in Brassicaceae and Fabaceae SSP gene promoters that are similar to experimentally characterized seed-specific cis-regulatory elements. Fabaceae SSP gene promoter sequences are also enriched in a novel, seed-specific E2Fb-like motif. Conserved motifs identified in Poaceae SSP gene promoters include a GCN4-like motif, two prolamin-box-like motifs and an Skn-1-like motif. Evidence of the presence of a variant of the TATA-box is found in the SSP gene promoters from the three plant families. Motifs discovered in SSP gene promoters were used to score whole-genome sets of promoters from Arabidopsis, soybean and rice. The highest-scoring promoters are associated with genes coding for different subunits or precursors of seed storage proteins. Conclusion Seed storage protein gene promoter motifs are conserved in diverse species, and different plant families are characterized by a distinct combination

Cloning and sequence analysis of the defective in anther ...

African Journals Online (AJOL)

To clone the defective in anther dehiscence1 (DAD1) gene fragment of Chinese kale, about 700 bp product was obtained by PCR amplification using Chinese kale genomic DNA as the template and a pair of specific primers designed according to the conserved sequence of DAD1 genes of Arabidopsis thaliana and ...

The complete mitochondrial genome sequence of Oceanic whitetip shark, Carcharhinus longimanus (Carcharhiniformes: Carcharhinidae).

Science.gov (United States)

Li, Weiwen; Dai, Xiaojie; Xu, Qianghua; Wu, Feng; Gao, Chunxia; Zhang, Yanbo

2016-05-01

The complete mitochondrial DNA sequence of Carcharhinus longimanus was determined and analyzed. The complete mtDNA genome sequence of C. longimanus was 16,706 bp in length. It contained 22 tRNA genes, 2 rRNA genes, 13 protein-coding genes and 2 non-conding regions: control region (D-loop) and origin of light-strand replication (OL). The complete mitogenome sequence information of C. longimanus can provide a useful data for further studies on molecular systematics, stock evaluation, taxonomic status and conservation genetics.

Genome-wide conserved consensus transcription factor binding motifs are hyper-methylated

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Down Thomas A

2010-09-01

Full Text Available Abstract Background DNA methylation can regulate gene expression by modulating the interaction between DNA and proteins or protein complexes. Conserved consensus motifs exist across the human genome ("predicted transcription factor binding sites": "predicted TFBS" but the large majority of these are proven by chromatin immunoprecipitation and high throughput sequencing (ChIP-seq not to be biological transcription factor binding sites ("empirical TFBS". We hypothesize that DNA methylation at conserved consensus motifs prevents promiscuous or disorderly transcription factor binding. Results Using genome-wide methylation maps of the human heart and sperm, we found that all conserved consensus motifs as well as the subset of those that reside outside CpG islands have an aggregate profile of hyper-methylation. In contrast, empirical TFBS with conserved consensus motifs have a profile of hypo-methylation. 40% of empirical TFBS with conserved consensus motifs resided in CpG islands whereas only 7% of all conserved consensus motifs were in CpG islands. Finally we further identified a minority subset of TF whose profiles are either hypo-methylated or neutral at their respective conserved consensus motifs implicating that these TF may be responsible for establishing or maintaining an un-methylated DNA state, or whose binding is not regulated by DNA methylation. Conclusions Our analysis supports the hypothesis that at least for a subset of TF, empirical binding to conserved consensus motifs genome-wide may be controlled by DNA methylation.

Seq2Logo: a method for construction and visualization of amino acid binding motifs and sequence profiles including sequence weighting, pseudo counts and two-sided representation of amino acid enrichment and depletion

DEFF Research Database (Denmark)

Thomsen, Martin Christen Frølund; Nielsen, Morten

2012-01-01

Seq2Logo is a web-based sequence logo generator. Sequence logos are a graphical representation of the information content stored in a multiple sequence alignment (MSA) and provide a compact and highly intuitive representation of the position-specific amino acid composition of binding motifs, active...... related to amino acid enrichment and depletion. Besides allowing input in the format of peptides and MSA, Seq2Logo accepts input as Blast sequence profiles, providing easy access for non-expert end-users to characterize and identify functionally conserved/variable amino acids in any given protein...... sites, etc. in biological sequences. Accurate generation of sequence logos is often compromised by sequence redundancy and low number of observations. Moreover, most methods available for sequence logo generation focus on displaying the position-specific enrichment of amino acids, discarding the equally...

Finding a (pine) needle in a haystack: chloroplast genome sequence divergence in rare and widespread pines

Science.gov (United States)

J.B. Whittall; J. Syring; M. Parks; J. Buenrostro; C. Dick; A. Liston; R. Cronn

2010-01-01

Critical to conservation efforts and other investigations at low taxonomic levels, DNA sequence data offer important insights into the distinctiveness, biogeographic partitioning, and evolutionary histories of species. The resolving power of DNA sequences is often limited by insufficient variability at the intraspecific level. This is particularly true of studies...

Evolutionarily conserved regions of the human c-myc protein can be uncoupled from transforming activity

International Nuclear Information System (INIS)

Sarid, J.; Halazonetis, T.D.; Murphy, W.; Leder, P.

1987-01-01

The myc family of oncogenes contains coding sequences that have been preserved in different species for over 400 million years. This conservation (which implies functional selection) is broadly represented throughout the C-terminal portion of the human c-myc protein but is largely restricted to three cluster of amino acid sequences in the N-terminal region. The authors have examined the role that the latter three regions of the c-myc protein might play in the transforming function of the c-myc gene. Several mutations, deletions and frameshifts, were introduced into the c-myc gene, and these mutant genes were tested for their ability to collaborate with the EJ-ras oncogene to transform rat embryo fibroblasts. Complete elimination of the first two N-terminal conserved segments abolished transforming activity. In contrast, genes altered in a portion of the second or the entire third conserved segment retained their transforming activity. Thus, the latter two segments are not required for the transformation process, suggesting that they serve another function related only to the normal expression of the c-myc gene

Development of ent-kaurene Oxidase-Based Conserved Intron Spanning Primers for Species Identification in the Genus Poa (Poaceae; Bluegrass

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Jonathan M. LaMantia

2018-04-01

Full Text Available Interspecific hybridization has been attempted to combine the heat and drought of Poa arachnifera Torr. with the turf quality characteristics of several Poa species. Confirmation of an F1 hybrid through morphological analysis of vegetative and flowering characteristics is often time consuming and ambiguous. Ent-kaurene oxidase (KO has been sequenced in rice, barley, and wheat. In rice, each of the five copies of KO gene has unique lengths for the first intron. Conserved intron spanning primers (CISP can be used as a DNA marker to exploit variations of intron lengths that flank conserved gene sequences. In the present study, we developed CISP to sequence partial genomic fragments of the KO gene from seven Poa species. Through sequence analysis, species-specific primers were also developed to produce co-dominant markers that can be used to identify interspecific hybrids between Texas bluegrass and six other Poa species used in the present study.

eShadow: A tool for comparing closely related sequences

Energy Technology Data Exchange (ETDEWEB)

Ovcharenko, Ivan; Boffelli, Dario; Loots, Gabriela G.

2004-01-15

Primate sequence comparisons are difficult to interpret due to the high degree of sequence similarity shared between such closely related species. Recently, a novel method, phylogenetic shadowing, has been pioneered for predicting functional elements in the human genome through the analysis of multiple primate sequence alignments. We have expanded this theoretical approach to create a computational tool, eShadow, for the identification of elements under selective pressure in multiple sequence alignments of closely related genomes, such as in comparisons of human to primate or mouse to rat DNA. This tool integrates two different statistical methods and allows for the dynamic visualization of the resulting conservation profile. eShadow also includes a versatile optimization module capable of training the underlying Hidden Markov Model to differentially predict functional sequences. This module grants the tool high flexibility in the analysis of multiple sequence alignments and in comparing sequences with different divergence rates. Here, we describe the eShadow comparative tool and its potential uses for analyzing both multiple nucleotide and protein alignments to predict putative functional elements. The eShadow tool is publicly available at http://eshadow.dcode.org/

A robust, simple genotyping-by-sequencing (GBS approach for high diversity species.

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Robert J Elshire

Full Text Available Advances in next generation technologies have driven the costs of DNA sequencing down to the point that genotyping-by-sequencing (GBS is now feasible for high diversity, large genome species. Here, we report a procedure for constructing GBS libraries based on reducing genome complexity with restriction enzymes (REs. This approach is simple, quick, extremely specific, highly reproducible, and may reach important regions of the genome that are inaccessible to sequence capture approaches. By using methylation-sensitive REs, repetitive regions of genomes can be avoided and lower copy regions targeted with two to three fold higher efficiency. This tremendously simplifies computationally challenging alignment problems in species with high levels of genetic diversity. The GBS procedure is demonstrated with maize (IBM and barley (Oregon Wolfe Barley recombinant inbred populations where roughly 200,000 and 25,000 sequence tags were mapped, respectively. An advantage in species like barley that lack a complete genome sequence is that a reference map need only be developed around the restriction sites, and this can be done in the process of sample genotyping. In such cases, the consensus of the read clusters across the sequence tagged sites becomes the reference. Alternatively, for kinship analyses in the absence of a reference genome, the sequence tags can simply be treated as dominant markers. Future application of GBS to breeding, conservation, and global species and population surveys may allow plant breeders to conduct genomic selection on a novel germplasm or species without first having to develop any prior molecular tools, or conservation biologists to determine population structure without prior knowledge of the genome or diversity in the species.

Purifying selection acts on coding and non-coding sequences of paralogous genes in Arabidopsis thaliana.

Science.gov (United States)

Hoffmann, Robert D; Palmgren, Michael

2016-06-13

Whole-genome duplications in the ancestors of many diverse species provided the genetic material for evolutionary novelty. Several models explain the retention of paralogous genes. However, how these models are reflected in the evolution of coding and non-coding sequences of paralogous genes is unknown. Here, we analyzed the coding and non-coding sequences of paralogous genes in Arabidopsis thaliana and compared these sequences with those of orthologous genes in Arabidopsis lyrata. Paralogs with lower expression than their duplicate had more nonsynonymous substitutions, were more likely to fractionate, and exhibited less similar expression patterns with their orthologs in the other species. Also, lower-expressed genes had greater tissue specificity. Orthologous conserved non-coding sequences in the promoters, introns, and 3' untranslated regions were less abundant at lower-expressed genes compared to their higher-expressed paralogs. A gene ontology (GO) term enrichment analysis showed that paralogs with similar expression levels were enriched in GO terms related to ribosomes, whereas paralogs with different expression levels were enriched in terms associated with stress responses. Loss of conserved non-coding sequences in one gene of a paralogous gene pair correlates with reduced expression levels that are more tissue specific. Together with increased mutation rates in the coding sequences, this suggests that similar forces of purifying selection act on coding and non-coding sequences. We propose that coding and non-coding sequences evolve concurrently following gene duplication.

Application of DNA barcodes in wildlife conservation in Tropical East Asia.

Science.gov (United States)

Wilson, John-James; Sing, Kong-Wah; Lee, Ping-Shin; Wee, Alison K S

2016-10-01

Over the past 50 years, Tropical East Asia has lost more biodiversity than any tropical region. Tropical East Asia is a megadiverse region with an acute taxonomic impediment. DNA barcodes are short standardized DNA sequences used for taxonomic purposes and have the potential to lessen the challenges of biodiversity inventory and assessments in regions where they are most needed. We reviewed DNA barcoding efforts in Tropical East Asia relative to other tropical regions. We suggest DNA barcodes (or metabarcodes from next-generation sequencers) may be especially useful for characterizing and connecting species-level biodiversity units in inventories encompassing taxa lacking formal description (particularly arthropods) and in large-scale, minimal-impact approaches to vertebrate monitoring and population assessments through secondary sources of DNA (invertebrate derived DNA and environmental DNA). We suggest interest and capacity for DNA barcoding are slowly growing in Tropical East Asia, particularly among the younger generation of researchers who can connect with the barcoding analogy and understand the need for new approaches to the conservation challenges being faced. © 2016 Society for Conservation Biology.

Repetitive sequences: the hidden diversity of heterochromatin in prochilodontid fish

Directory of Open Access Journals (Sweden)

Maria L. Terencio

2015-08-01

Full Text Available The structure and organization of repetitive elements in fish genomes are still relatively poorly understood, although most of these elements are believed to be located in heterochromatic regions. Repetitive elements are considered essential in evolutionary processes as hotspots for mutations and chromosomal rearrangements, among other functions – thus providing new genomic alternatives and regulatory sites for gene expression. The present study sought to characterize repetitive DNA sequences in the genomes of Semaprochilodus insignis (Jardine & Schomburgk, 1841 and Semaprochilodus taeniurus (Valenciennes, 1817 and identify regions of conserved syntenic blocks in this genome fraction of three species of Prochilodontidae (S. insignis, S. taeniurus, and Prochilodus lineatus (Valenciennes, 1836 by cross-FISH using Cot-1 DNA (renaturation kinetics probes. We found that the repetitive fractions of the genomes of S. insignis and S. taeniurus have significant amounts of conserved syntenic blocks in hybridization sites, but with low degrees of similarity between them and the genome of P. lineatus, especially in relation to B chromosomes. The cloning and sequencing of the repetitive genomic elements of S. insignis and S. taeniurus using Cot-1 DNA identified 48 fragments that displayed high similarity with repetitive sequences deposited in public DNA databases and classified as microsatellites, transposons, and retrotransposons. The repetitive fractions of the S. insignis and S. taeniurus genomes exhibited high degrees of conserved syntenic blocks in terms of both the structures and locations of hybridization sites, but a low degree of similarity with the syntenic blocks of the P. lineatus genome. Future comparative analyses of other prochilodontidae species will be needed to advance our understanding of the organization and evolution of the genomes in this group of fish.

Planarian homeobox genes: cloning, sequence analysis, and expression.

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Garcia-Fernàndez, J; Baguñà, J; Saló, E

1991-01-01

Freshwater planarians (Platyhelminthes, Turbellaria, and Tricladida) are acoelomate, triploblastic, unsegmented, and bilaterally symmetrical organisms that are mainly known for their ample power to regenerate a complete organism from a small piece of their body. To identify potential pattern-control genes in planarian regeneration, we have isolated two homeobox-containing genes, Dth-1 and Dth-2 [Dugesia (Girardia) tigrina homeobox], by using degenerate oligonucleotides corresponding to the most conserved amino acid sequence from helix-3 of the homeodomain. Dth-1 and Dth-2 homeodomains are closely related (68% at the nucleotide level and 78% at the protein level) and show the conserved residues characteristic of the homeodomains identified to data. Similarity with most homeobox sequences is low (30-50%), except with Drosophila NK homeodomains (80-82% with NK-2) and the rodent TTF-1 homeodomain (77-87%). Some unusual amino acid residues specific to NK-2, TTF-1, Dth-1, and Dth-2 can be observed in the recognition helix (helix-3) and may define a family of homeodomains. The deduced amino acid sequences from the cDNAs contain, in addition to the homeodomain, other domains also present in various homeobox-containing genes. The expression of both genes, detected by Northern blot analysis, appear slightly higher in cephalic regions than in the rest of the intact organism, while a slight increase is detected in the central period (5 days) or regeneration. Images PMID:1714599

Identification of evolutionarily conserved Momordica charantia microRNAs using computational approach and its utility in phylogeny analysis.

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Thirugnanasambantham, Krishnaraj; Saravanan, Subramanian; Karikalan, Kulandaivelu; Bharanidharan, Rajaraman; Lalitha, Perumal; Ilango, S; HairulIslam, Villianur Ibrahim

2015-10-01

Momordica charantia (bitter gourd, bitter melon) is a monoecious Cucurbitaceae with anti-oxidant, anti-microbial, anti-viral and anti-diabetic potential. Molecular studies on this economically valuable plant are very essential to understand its phylogeny and evolution. MicroRNAs (miRNAs) are conserved, small, non-coding RNA with ability to regulate gene expression by bind the 3' UTR region of target mRNA and are evolved at different rates in different plant species. In this study we have utilized homology based computational approach and identified 27 mature miRNAs for the first time from this bio-medically important plant. The phylogenetic tree developed from binary data derived from the data on presence/absence of the identified miRNAs were noticed to be uncertain and biased. Most of the identified miRNAs were highly conserved among the plant species and sequence based phylogeny analysis of miRNAs resolved the above difficulties in phylogeny approach using miRNA. Predicted gene targets of the identified miRNAs revealed their importance in regulation of plant developmental process. Reported miRNAs held sequence conservation in mature miRNAs and the detailed phylogeny analysis of pre-miRNA sequences revealed genus specific segregation of clusters. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequence analysis of dolphin ferritin H and L subunits and possible iron-dependent translational control of dolphin ferritin gene

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Sasaki Yukako

2008-10-01

Full Text Available Abstract Background Iron-storage protein, ferritin plays a central role in iron metabolism. Ferritin has dual function to store iron and segregate iron for protection of iron-catalyzed reactive oxygen species. Tissue ferritin is composed of two kinds of subunits (H: heavy chain or heart-type subunit; L: light chain or liver-type subunit. Ferritin gene expression is controlled at translational level in iron-dependent manner or at transcriptional level in iron-independent manner. However, sequencing analysis of marine mammalian ferritin subunits has not yet been performed fully. The purpose of this study is to reveal cDNA-derived amino acid sequences of cetacean ferritin H and L subunits, and demonstrate the possibility of expression of these subunits, especially H subunit, by iron. Methods Sequence analyses of cetacean ferritin H and L subunits were performed by direct sequencing of polymerase chain reaction (PCR fragments from cDNAs generated via reverse transcription-PCR of leukocyte total RNA prepared from blood samples of six different dolphin species (Pseudorca crassidens, Lagenorhynchus obliquidens, Grampus griseus, Globicephala macrorhynchus, Tursiops truncatus, and Delphinapterus leucas. The putative iron-responsive element sequence in the 5'-untranslated region of the six different dolphin species was revealed by direct sequencing of PCR fragments obtained using leukocyte genomic DNA. Results Dolphin H and L subunits consist of 182 and 174 amino acids, respectively, and amino acid sequence identities of ferritin subunits among these dolphins are highly conserved (H: 99–100%, (99→98 ; L: 98–100%. The conserved 28 bp IRE sequence was located -144 bp upstream from the initiation codon in the six different dolphin species. Conclusion These results indicate that six different dolphin species have conserved ferritin sequences, and suggest that these genes are iron-dependently expressed.

Comparative Annotation of Viral Genomes with Non-Conserved Gene Structure

DEFF Research Database (Denmark)

de Groot, Saskia; Mailund, Thomas; Hein, Jotun

2007-01-01

Motivation: Detecting genes in viral genomes is a complex task. Due to the biological necessity of them being constrained in length, RNA viruses in particular tend to code in overlapping reading frames. Since one amino acid is encoded by a triplet of nucleic acids, up to three genes may be coded...... allows for coding in unidirectional nested and overlapping reading frames, to annotate two homologous aligned viral genomes. Our method does not insist on conserved gene structure between the two sequences, thus making it applicable for the pairwise comparison of more distantly related sequences. Results...... and HIV2, as well as of two different Hepatitis Viruses, attaining results of ~87% sensitivity and ~98.5% specificity. We subsequently incorporate prior knowledge by "knowing" the gene structure of one sequence and annotating the other conditional on it. Boosting accuracy close to perfect we demonstrate...

Conservation Genetics of the Cheetah: Lessons Learned and New Opportunities.

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O'Brien, Stephen J; Johnson, Warren E; Driscoll, Carlos A; Dobrynin, Pavel; Marker, Laurie

2017-09-01

The dwindling wildlife species of our planet have become a cause célèbre for conservation groups, governments, and concerned citizens throughout the world. The application of powerful new genetic technologies to surviving populations of threatened mammals has revolutionized our ability to recognize hidden perils that afflict them. We have learned new lessons of survival, adaptation, and evolution from viewing the natural history of genomes in hundreds of detailed studies. A single case history of one species, the African cheetah, Acinonyx jubatus, is here reviewed to reveal a long-term story of conservation challenges and action informed by genetic discoveries and insights. A synthesis of 3 decades of data, interpretation, and controversy, capped by whole genome sequence analysis of cheetahs, provides a compelling tale of conservation relevance and action to protect this species and other threatened wildlife. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Conservation patterns of HIV-1 RT connection and RNase H domains: identification of new mutations in NRTI-treated patients.

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André F A Santos

Full Text Available BACKGROUND: Although extensive HIV drug resistance information is available for the first 400 amino acids of its reverse transcriptase, the impact of antiretroviral treatment in C-terminal domains of Pol (thumb, connection and RNase H is poorly understood. METHODS AND FINDINGS: We wanted to characterize conserved regions in RT C-terminal domains among HIV-1 group M subtypes and CRF. Additionally, we wished to identify NRTI-related mutations in HIV-1 RT C-terminal domains. We sequenced 118 RNase H domains from clinical viral isolates in Brazil, and analyzed 510 thumb and connection domain and 450 RNase H domain sequences collected from public HIV sequence databases, together with their treatment status and histories. Drug-naïve and NRTI-treated datasets were compared for intra- and inter-group conservation, and differences were determined using Fisher's exact tests. One third of RT C-terminal residues were found to be conserved among group M variants. Three mutations were found exclusively in NRTI-treated isolates. Nine mutations in the connection and 6 mutations in the RNase H were associated with NRTI treatment in subtype B. Some of them lay in or close to amino acid residues which contact nucleic acid or near the RNase H active site. Several of the residues pointed out herein have been recently associated to NRTI exposure or increase drug resistance to NRTI. CONCLUSIONS: This is the first comprehensive genotypic analysis of a large sequence dataset that describes NRTI-related mutations in HIV-1 RT C-terminal domains in vivo. The findings into the conservation of RT C-terminal domains may pave the way to more rational drug design initiatives targeting those regions.

Sequencing and analysis of the Mediterranean amphioxus (Branchiostoma lanceolatum transcriptome.

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Silvan Oulion

Full Text Available BACKGROUND: The basally divergent phylogenetic position of amphioxus (Cephalochordata, as well as its conserved morphology, development and genetics, make it the best proxy for the chordate ancestor. Particularly, studies using the amphioxus model help our understanding of vertebrate evolution and development. Thus, interest for the amphioxus model led to the characterization of both the transcriptome and complete genome sequence of the American species, Branchiostoma floridae. However, recent technical improvements allowing induction of spawning in the laboratory during the breeding season on a daily basis with the Mediterranean species Branchiostoma lanceolatum have encouraged European Evo-Devo researchers to adopt this species as a model even though no genomic or transcriptomic data have been available. To fill this need we used the pyrosequencing method to characterize the B. lanceolatum transcriptome and then compared our results with the published transcriptome of B. floridae. RESULTS: Starting with total RNA from nine different developmental stages of B. lanceolatum, a normalized cDNA library was constructed and sequenced on Roche GS FLX (Titanium mode. Around 1.4 million of reads were produced and assembled into 70,530 contigs (average length of 490 bp. Overall 37% of the assembled sequences were annotated by BlastX and their Gene Ontology terms were determined. These results were then compared to genomic and transcriptomic data of B. floridae to assess similarities and specificities of each species. CONCLUSION: We obtained a high-quality amphioxus (B. lanceolatum reference transcriptome using a high throughput sequencing approach. We found that 83% of the predicted genes in the B. floridae complete genome sequence are also found in the B. lanceolatum transcriptome, while only 41% were found in the B. floridae transcriptome obtained with traditional Sanger based sequencing. Therefore, given the high degree of sequence conservation

Evolutionary relationships in the ilarviruses: nucleotide sequence of prunus necrotic ringspot virus RNA 3.

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Sánchez-Navarro, J A; Pallás, V

1997-01-01

The complete nucleotide sequence of an isolate of prunus necrotic ringspot virus (PNRSV) RNA 3 has been determined. Elucidation of the amino acid sequence of the proteins encoded by the two large open reading frames (ORFs) allowed us to carry out comparative and phylogenetic studies on the movement (MP) and coat (CP) proteins in the ilarvirus group. Amino acid sequence comparison of the MP revealed a highly conserved basic sequence motif with an amphipathic alpha-helical structure preceding the conserved motif of the '30K superfamily' proposed by Mushegian and Koonin [26] for MP's. Within this '30K' motif a strictly conserved transmembrane domain is present in all ilarviruses sequenced so far. At the amino-terminal end, prune dwarf virus (PDV) has an extension not present in other ilarviruses but which is observed in all bromo- and cucumoviruses, suggesting a common ancestor or a recombinational event in the Bromoviridae family. Examination of the N-terminus of the CP's of all ilarviruses revealed a highly basic region, part of which resembles the Arg-rich motif that has been characterized in the RNA-binding protein family. This motif has also been found in the other members of the Bromoviridae family, suggesting its involvement in a structural function. Furthermore this region is required for infectivity in ilarviruses. The similarities found in this Arg-rich motif are discussed in terms of this process known as genome activation. Finally, phylogenetic analysis of both the MP and CP proteins revealed a higher relationship of A1MV to PNRSV, apple mosaic virus (ApMV) and PDV than any other member of the ilarvirus group. In that sense, A1MV should be considered as a true ilarvirus instead of forming a distinct group of viruses.

Identification of novel conserved functional motifs across most Influenza A viral strains

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El-Azab Iman

2011-01-01

Full Text Available Abstract Background Influenza A virus poses a continuous threat to global public health. Design of novel universal drugs and vaccine requires a careful analysis of different strains of Influenza A viral genome from diverse hosts and subtypes. We performed a systematic in silico analysis of Influenza A viral segments of all available Influenza A viral strains and subtypes and grouped them based on host, subtype, and years isolated, and through multiple sequence alignments we extrapolated conserved regions, motifs, and accessible regions for functional mapping and annotation. Results Across all species and strains 87 highly conserved regions (conservation percentage > = 90% and 19 functional motifs (conservation percentage = 100% were found in PB2, PB1, PA, NP, M, and NS segments. The conservation percentage of these segments ranged between 94 - 98% in human strains (the most conserved, 85 - 93% in swine strains (the most variable, and 91 - 94% in avian strains. The most conserved segment was different in each host (PB1 for human strains, NS for avian strains, and M for swine strains. Target accessibility prediction yielded 324 accessible regions, with a single stranded probability > 0.5, of which 78 coincided with conserved regions. Some of the interesting annotations in these regions included sites for protein-protein interactions, the RNA binding groove, and the proton ion channel. Conclusions The influenza virus has evolved to adapt to its host through variations in the GC content and conservation percentage of the conserved regions. Nineteen universal conserved functional motifs were discovered, of which some were accessible regions with interesting biological functions. These regions will serve as a foundation for universal drug targets as well as universal vaccine design.

Binning sequences using very sparse labels within a metagenome

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Halgamuge Saman K

2008-04-01

Full Text Available Abstract Background In metagenomic studies, a process called binning is necessary to assign contigs that belong to multiple species to their respective phylogenetic groups. Most of the current methods of binning, such as BLAST, k-mer and PhyloPythia, involve assigning sequence fragments by comparing sequence similarity or sequence composition with already-sequenced genomes that are still far from comprehensive. We propose a semi-supervised seeding method for binning that does not depend on knowledge of completed genomes. Instead, it extracts the flanking sequences of highly conserved 16S rRNA from the metagenome and uses them as seeds (labels to assign other reads based on their compositional similarity. Results The proposed seeding method is implemented on an unsupervised Growing Self-Organising Map (GSOM, and called Seeded GSOM (S-GSOM. We compared it with four well-known semi-supervised learning methods in a preliminary test, separating random-length prokaryotic sequence fragments sampled from the NCBI genome database. We identified the flanking sequences of the highly conserved 16S rRNA as suitable seeds that could be used to group the sequence fragments according to their species. S-GSOM showed superior performance compared to the semi-supervised methods tested. Additionally, S-GSOM may also be used to visually identify some species that do not have seeds. The proposed method was then applied to simulated metagenomic datasets using two different confidence threshold settings and compared with PhyloPythia, k-mer and BLAST. At the reference taxonomic level Order, S-GSOM outperformed all k-mer and BLAST results and showed comparable results with PhyloPythia for each of the corresponding confidence settings, where S-GSOM performed better than PhyloPythia in the ≥ 10 reads datasets and comparable in the ≥ 8 kb benchmark tests. Conclusion In the task of binning using semi-supervised learning methods, results indicate S-GSOM to be the best of

Dinoflagellate phylogeny as inferred from heat shock protein 90 and ribosomal gene sequences.

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Mona Hoppenrath

2010-10-01

Full Text Available Interrelationships among dinoflagellates in molecular phylogenies are largely unresolved, especially in the deepest branches. Ribosomal DNA (rDNA sequences provide phylogenetic signals only at the tips of the dinoflagellate tree. Two reasons for the poor resolution of deep dinoflagellate relationships using rDNA sequences are (1 most sites are relatively conserved and (2 there are different evolutionary rates among sites in different lineages. Therefore, alternative molecular markers are required to address the deeper phylogenetic relationships among dinoflagellates. Preliminary evidence indicates that the heat shock protein 90 gene (Hsp90 will provide an informative marker, mainly because this gene is relatively long and appears to have relatively uniform rates of evolution in different lineages.We more than doubled the previous dataset of Hsp90 sequences from dinoflagellates by generating additional sequences from 17 different species, representing seven different orders. In order to concatenate the Hsp90 data with rDNA sequences, we supplemented the Hsp90 sequences with three new SSU rDNA sequences and five new LSU rDNA sequences. The new Hsp90 sequences were generated, in part, from four additional heterotrophic dinoflagellates and the type species for six different genera. Molecular phylogenetic analyses resulted in a paraphyletic assemblage near the base of the dinoflagellate tree consisting of only athecate species. However, Noctiluca was never part of this assemblage and branched in a position that was nested within other lineages of dinokaryotes. The phylogenetic trees inferred from Hsp90 sequences were consistent with trees inferred from rDNA sequences in that the backbone of the dinoflagellate clade was largely unresolved.The sequence conservation in both Hsp90 and rDNA sequences and the poor resolution of the deepest nodes suggests that dinoflagellates reflect an explosive radiation in morphological diversity in their recent

Sequencing and de novo analysis of a coral larval transcriptome using 454 GSFlx

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Colbourne John K

2009-05-01

Full Text Available Abstract Background New methods are needed for genomic-scale analysis of emerging model organisms that exemplify important biological questions but lack fully sequenced genomes. For example, there is an urgent need to understand the potential for corals to adapt to climate change, but few molecular resources are available for studying these processes in reef-building corals. To facilitate genomics studies in corals and other non-model systems, we describe methods for transcriptome sequencing using 454, as well as strategies for assembling a useful catalog of genes from the output. We have applied these methods to sequence the transcriptome of planulae larvae from the coral Acropora millepora. Results More than 600,000 reads produced in a single 454 sequencing run were assembled into ~40,000 contigs with five-fold average sequencing coverage. Based on sequence similarity with known proteins, these analyses identified ~11,000 different genes expressed in a range of conditions including thermal stress and settlement induction. Assembled sequences were annotated with gene names, conserved domains, and Gene Ontology terms. Targeted searches using these annotations identified the majority of genes associated with essential metabolic pathways and conserved signaling pathways, as well as novel candidate genes for stress-related processes. Comparisons with the genome of the anemone Nematostella vectensis revealed ~8,500 pairs of orthologs and ~100 candidate coral-specific genes. More than 30,000 SNPs were detected in the coral sequences, and a subset of these validated by re-sequencing. Conclusion The methods described here for deep sequencing of the transcriptome should be widely applicable to generate catalogs of genes and genetic markers in emerging model organisms. Our data provide the most comprehensive sequence resource currently available for reef-building corals, and include an extensive collection of potential genetic markers for association and

Serine Protease Variants Encoded by Echis ocellatus Venom Gland cDNA: Cloning and Sequencing Analysis

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S. S. Hasson

2010-01-01

Full Text Available Envenoming by Echis saw-scaled viper is the leading cause of death and morbidity in Africa due to snake bite. Despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. Here, we report the cloning of cDNA sequences encoding four groups or isoforms of the haemostasis-disruptive Serine protease proteins (SPs from the venom glands of Echis ocellatus. All these SP sequences encoded the cysteine residues scaffold that form the 6-disulphide bonds responsible for the characteristic tertiary structure of venom serine proteases. All the Echis ocellatus EoSP groups showed varying degrees of sequence similarity to published viper venom SPs. However, these groups also showed marked intercluster sequence conservation across them which were significantly different from that of previously published viper SPs. Because viper venom SPs exhibit a high degree of sequence similarity and yet exert profoundly different effects on the mammalian haemostatic system, no attempt was made to assign functionality to the new Echis ocellatus EoSPs on the basis of sequence alone. The extraordinary level of interspecific and intergeneric sequence conservation exhibited by the Echis ocellatus EoSPs and analogous serine proteases from other viper species leads us to speculate that antibodies to representative molecules should neutralise (that we will exploit, by epidermal DNA immunization the biological function of this important group of venom toxins in vipers that are distributed throughout Africa, the Middle East, and the Indian subcontinent.

Allele frequencies of variants in ultra conserved elements identify selective pressure on transcription factor binding.

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Toomas Silla

Full Text Available Ultra-conserved genes or elements (UCGs/UCEs in the human genome are extreme examples of conservation. We characterized natural variations in 2884 UCEs and UCGs in two distinct populations; Singaporean Chinese (n = 280 and Italian (n = 501 by using a pooled sample, targeted capture, sequencing approach. We identify, with high confidence, in these regions the abundance of rare SNVs (MAF5% are more often found in relatively less-conserved nucleotides within UCEs, compared to rare variants. Moreover, prevalent variants are less likely to overlap transcription factor binding site. Using SNPfold we found no significant influence of RNA secondary structure on UCE conservation. All together, these results suggest UCEs are not under selective pressure as a stretch of DNA but are under differential evolutionary pressure on the single nucleotide level.

Effect of the sequence data deluge on the performance of methods for detecting protein functional residues.

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Garrido-Martín, Diego; Pazos, Florencio

2018-02-27

The exponential accumulation of new sequences in public databases is expected to improve the performance of all the approaches for predicting protein structural and functional features. Nevertheless, this was never assessed or quantified for some widely used methodologies, such as those aimed at detecting functional sites and functional subfamilies in protein multiple sequence alignments. Using raw protein sequences as only input, these approaches can detect fully conserved positions, as well as those with a family-dependent conservation pattern. Both types of residues are routinely used as predictors of functional sites and, consequently, understanding how the sequence content of the databases affects them is relevant and timely. In this work we evaluate how the growth and change with time in the content of sequence databases affect five sequence-based approaches for detecting functional sites and subfamilies. We do that by recreating historical versions of the multiple sequence alignments that would have been obtained in the past based on the database contents at different time points, covering a period of 20 years. Applying the methods to these historical alignments allows quantifying the temporal variation in their performance. Our results show that the number of families to which these methods can be applied sharply increases with time, while their ability to detect potentially functional residues remains almost constant. These results are informative for the methods' developers and final users, and may have implications in the design of new sequencing initiatives.

[Interconnection between architecture of protein globule and disposition of conformational conservative oligopeptides in proteins from one protein family].

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Batianovskiĭ, A V; Filatov, I V; Namiot, V A; Esipova, N G; Volotovskiĭ, I D

2012-01-01

It was shown that selective interactions between helical segments of macromolecules can realize in globular proteins in the segments characterized by the same periodicities of charge distribution i.e. between conformationally conservative oligopeptides. It was found that in the macromolecules of alpha-helical proteins conformationally conservative oligopeptides are disposed at a distance being characteristic of direct interactions. For representatives of many structural families of alpha-type proteins specific disposition of conformationally conservative segments is observed. This disposition is inherent to a particular structural family. Disposition of conformationally conservative segments is not related to homology of the amino acid sequence but reflects peculiarities of native 3D-architectures of protein globules.

Functional analysis of bipartite begomovirus coat protein promoter sequences

International Nuclear Information System (INIS)

Lacatus, Gabriela; Sunter, Garry

2008-01-01

We demonstrate that the AL2 gene of Cabbage leaf curl virus (CaLCuV) activates the CP promoter in mesophyll and acts to derepress the promoter in vascular tissue, similar to that observed for Tomato golden mosaic virus (TGMV). Binding studies indicate that sequences mediating repression and activation of the TGMV and CaLCuV CP promoter specifically bind different nuclear factors common to Nicotiana benthamiana, spinach and tomato. However, chromatin immunoprecipitation demonstrates that TGMV AL2 can interact with both sequences independently. Binding of nuclear protein(s) from different crop species to viral sequences conserved in both bipartite and monopartite begomoviruses, including TGMV, CaLCuV, Pepper golden mosaic virus and Tomato yellow leaf curl virus suggests that bipartite begomoviruses bind common host factors to regulate the CP promoter. This is consistent with a model in which AL2 interacts with different components of the cellular transcription machinery that bind viral sequences important for repression and activation of begomovirus CP promoters

Conserved genomic organisation of Group B Sox genes in insects.

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Woerfel Gertrud

2005-05-01

Full Text Available Abstract Background Sox domain containing genes are important metazoan transcriptional regulators implicated in a wide rage of developmental processes. The vertebrate B subgroup contains the Sox1, Sox2 and Sox3 genes that have early functions in neural development. Previous studies show that Drosophila Group B genes have been functionally conserved since they play essential roles in early neural specification and mutations in the Drosophila Dichaete and SoxN genes can be rescued with mammalian Sox genes. Despite their importance, the extent and organisation of the Group B family in Drosophila has not been fully characterised, an important step in using Drosophila to examine conserved aspects of Group B Sox gene function. Results We have used the directed cDNA sequencing along with the output from the publicly-available genome sequencing projects to examine the structure of Group B Sox domain genes in Drosophila melanogaster, Drosophila pseudoobscura, Anopheles gambiae and Apis mellifora. All of the insect genomes contain four genes encoding Group B proteins, two of which are intronless, as is the case with vertebrate group B genes. As has been previously reported and unusually for Group B genes, two of the insect group B genes, Sox21a and Sox21b, contain introns within their DNA-binding domains. We find that the highly unusual multi-exon structure of the Sox21b gene is common to the insects. In addition, we find that three of the group B Sox genes are organised in a linked cluster in the insect genomes. By in situ hybridisation we show that the pattern of expression of each of the four group B genes during embryogenesis is conserved between D. melanogaster and D. pseudoobscura. Conclusion The DNA-binding domain sequences and genomic organisation of the group B genes have been conserved over 300 My of evolution since the last common ancestor of the Hymenoptera and the Diptera. Our analysis suggests insects have two Group B1 genes, SoxN and

Screening of broad spectrum natural pesticides against conserved target arginine kinase in cotton pests by molecular modeling.

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Sakthivel, Seethalakshmi; Habeeb, S K M; Raman, Chandrasekar

2018-03-12

Cotton is an economically important crop and its production is challenged by the diversity of pests and related insecticide resistance. Identification of the conserved target across the cotton pest will help to design broad spectrum insecticide. In this study, we have identified conserved sequences by Expressed Sequence Tag profiling from three cotton pests namely Aphis gossypii, Helicoverpa armigera, and Spodoptera exigua. One target protein arginine kinase having a key role in insect physiology and energy metabolism was studied further using homology modeling, virtual screening, molecular docking, and molecular dynamics simulation to identify potential biopesticide compounds from the Zinc natural database. We have identified four compounds having excellent inhibitor potential against the identified broad spectrum target which are highly specific to invertebrates.

Setting Conservation Priorities in a Widespread Species: Phylogeographic and Physiological Variation in the Lake Chub, Couesius plumbeus (Pisces: Cyprinidae

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Patricia M. Schulte

2013-04-01

Full Text Available Defining units of conservation below the species level is a widely accepted conservation priority, but is especially challenging for widespread taxa that have experienced diverse geographic histories and exist across heterogenous environments. The lake chub (Pisces: Couesius plumbeus is a widespread freshwater fish in North America and occurs from the southcentral USA to northwestern Alaska and Canada. We used mtDNA sequence analysis to test for divergent lineages predicted to occur as a result of survival of lake chub in distinct glacial refugia. Lake chub consisted of two major mtDNA lineages separated by 3.8% sequence divergence which are probably late to pre-Pleistocene in origin. We combined these data with those consistent with thermal adaptation in fish living in thermal springs versus those living in a lake with wide seasonal temperature variation, and with data on distribution of lake chub in major watershed units. We assessed these data against objective criteria developed to identify conservation units under Canadian endangered species legislation. Our analysis identified twelve major units of conservation within C. plumbeus that could be assessed under Canada’s Species-at-Risk Act. Our study illustrates how different character traits manifested at very different spatial scales can be used to define conservation units within widely-distributed taxa.

A comprehensive analysis of three Asiatic black bear mitochondrial genomes (subspecies ussuricus, formosanus and mupinensis), with emphasis on the complete mtDNA sequence of Ursus thibetanus ussuricus (Ursidae).

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Hwang, Dae-Sik; Ki, Jang-Seu; Jeong, Dong-Hyuk; Kim, Bo-Hyun; Lee, Bae-Keun; Han, Sang-Hoon; Lee, Jae-Seong

2008-08-01

In the present paper, we describe the mitochondrial genome sequence of the Asiatic black bear (Ursus thibetanus ussuricus) with particular emphasis on the control region (CR), and compared with mitochondrial genomes on molecular relationships among the bears. The mitochondrial genome sequence of U. thibetanus ussuricus was 16,700 bp in size with mostly conserved structures (e.g. 13 protein-coding, two rRNA genes, 22 tRNA genes). The CR consisted of several typical conserved domains such as F, E, D, and C boxes, and a conserved sequence block. Nucleotide sequences and the repeated motifs in the CR were different among the bear species, and their copy numbers were also variable according to populations, even within F1 generations of U. thibetanus ussuricus. Comparative analyses showed that the CR D1 region was highly informative for the discrimination of the bear family. These findings suggest that nucleotide sequences of both repeated motifs and CR D1 in the bear family are good markers for species discriminations.

Sequence analysis of the aminoacylase-1 family. A new proposed signature for metalloexopeptidases.

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Biagini, A; Puigserver, A

2001-03-01

The amino acid sequence analysis of the human and porcine aminoacylases-1, the carboxypeptidase S precursor from Saccharomyces cerevisiae, the succinyl-diaminopimelate desuccinylase from Escherichia coli, Haemophilus influenzae and Corynebacterium glutamicum, the acetylornithine deacetylase from Escherichia coli and Dictyostelium discoideum and the carboxypeptidase G(2) precursor from Pseudomonas strain, using the Basic Local Alignment Search Tool (BLAST) and the Position-Specific Iterated BLAST (PSI-BLAST), allowed us to suggest that all these enzymes, which share common functional and biochemical features, belong to the same structural family. The three amino acid blocks which were found to be highly conserved, using the CLUSTAL W program, could be assigned to the catalytic active site, based on the general three-dimensional structure of the carboxypeptidase G(2) from the Pseudomonas strain precursor. Six additional proteins with the same signature have been retrieved after performing two successive PSI-BLAST iterations using the sequence of the conserved motif, namely Lactobacillus delbrueckii aminoacyl-histidine dipeptidase, Streptomyces griseus aminopeptidase, Saccharomyces cerevisiae aminopeptidase Y precursor, two Bacillus stearothermophilus N-carbamyl-L-amino acid amidohydrolases and Pseudomonas sp. hydantoin utilization protein C. The three conserved amino acid motifs corresponded to the following blocks: (i) [S, G, A]-H-x-D-x-V; (ii) G-x-x-D; and (iii) x-E-E. This new sequence signature is clearly different from that commonly reported in the literature for proteins belonging to the ArgE/DapE/CPG2/YscS family.

The genome sequence and effector complement of the flax rust pathogen Melampsora lini

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Adnane eNemri

2014-03-01

Full Text Available Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp. Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimise parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analysed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote

The genome sequence and effector complement of the flax rust pathogen Melampsora lini.

Science.gov (United States)

Nemri, Adnane; Saunders, Diane G O; Anderson, Claire; Upadhyaya, Narayana M; Win, Joe; Lawrence, Gregory J; Jones, David A; Kamoun, Sophien; Ellis, Jeffrey G; Dodds, Peter N

2014-01-01

Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed most extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp). Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimize parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analyzed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote infection on their

Paradoxical DNA repair and peroxide resistance gene conservation in Bacillus pumilus SAFR-032.

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Jason Gioia

Full Text Available BACKGROUND: Bacillus spores are notoriously resistant to unfavorable conditions such as UV radiation, gamma-radiation, H2O2, desiccation, chemical disinfection, or starvation. Bacillus pumilus SAFR-032 survives standard decontamination procedures of the Jet Propulsion Lab spacecraft assembly facility, and both spores and vegetative cells of this strain exhibit elevated resistance to UV radiation and H2O2 compared to other Bacillus species. PRINCIPAL FINDINGS: The genome of B. pumilus SAFR-032 was sequenced and annotated. Lists of genes relevant to DNA repair and the oxidative stress response were generated and compared to B. subtilis and B. licheniformis. Differences in conservation of genes, gene order, and protein sequences are highlighted because they potentially explain the extreme resistance phenotype of B. pumilus. The B. pumilus genome includes genes not found in B. subtilis or B. licheniformis and conserved genes with sequence divergence, but paradoxically lacks several genes that function in UV or H2O2 resistance in other Bacillus species. SIGNIFICANCE: This study identifies several candidate genes for further research into UV and H2O2 resistance. These findings will help explain the resistance of B. pumilus and are applicable to understanding sterilization survival strategies of microbes.

Integrating conservation costs into sea level rise adaptive conservation prioritization

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Mingjian Zhu

2015-07-01

Full Text Available Biodiversity conservation requires strategic investment as resources for conservation are often limited. As sea level rises, it is important and necessary to consider both sea level rise and costs in conservation decision making. In this study, we consider costs of conservation in an integrated modeling process that incorporates a geomorphological model (SLAMM, species habitat models, and conservation prioritization (Zonation to identify conservation priorities in the face of landscape dynamics due to sea level rise in the Matanzas River basin of northeast Florida. Compared to conservation priorities that do not consider land costs in the analysis process, conservation priorities that consider costs in the planning process change significantly. The comparison demonstrates that some areas with high conservation values might be identified as lower priorities when integrating economic costs in the planning process and some areas with low conservation values might be identified as high priorities when considering costs in the planning process. This research could help coastal resources managers make informed decisions about where and how to allocate conservation resources more wisely to facilitate biodiversity adaptation to sea level rise.

Conserved and variable domains of RNase MRP RNA.

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Dávila López, Marcela; Rosenblad, Magnus Alm; Samuelsson, Tore

2009-01-01

Ribonuclease MRP is a eukaryotic ribonucleoprotein complex consisting of one RNA molecule and 7-10 protein subunits. One important function of MRP is to catalyze an endonucleolytic cleavage during processing of rRNA precursors. RNase MRP is evolutionary related to RNase P which is critical for tRNA processing. A large number of MRP RNA sequences that now are available have been used to identify conserved primary and secondary structure features of the molecule. MRP RNA has structural features in common with P RNA such as a conserved catalytic core, but it also has unique features and is characterized by a domain highly variable between species. Information regarding primary and secondary structure features is of interest not only in basic studies of the function of MRP RNA, but also because mutations in the RNA give rise to human genetic diseases such as cartilage-hair hypoplasia.

Conservation potential of agricultural water conservation subsidies

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Huffaker, Ray

2008-07-01

A current policy subsidizes farmers to invest in improved on-farm irrigation efficiency, expecting water to be conserved off farm. Contrary to expectation, water has been increasingly depleted in some regions after such improvements. This paper investigates the policy's failure to conserve water consistently by (1) formulating an economic model of irrigated crop production to determine a profit-maximizing irrigator's range of responses to a subsidy and (2) embedding these responses into hypothetical streamflow diagrams to ascertain their potential to conserve water under various hydrologic regimes. Testable hypotheses are developed to predict the conservation potential of a subsidy in real-world application.

Advances in conservation endocrinology: the application of molecular approaches to the conservation of endangered species.

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Tubbs, Christopher; McDonough, Caitlin E; Felton, Rachel; Milnes, Matthew R

2014-07-01

Among the numerous societal benefits of comparative endocrinology is the application of our collective knowledge of hormone signaling towards the conservation of threatened and endangered species - conservation endocrinology. For several decades endocrinologists have used longitudinal hormone profiles to monitor reproductive status in a multitude of species. Knowledge of reproductive status among individuals has been used to assist in the management of captive and free-ranging populations. More recently, researchers have begun utilizing molecular and cell-based techniques to gain a more complete understanding of hormone signaling in wildlife species, and to identify potential causes of disrupted hormone signaling. In this review we examine various in vitro approaches we have used to compare estrogen receptor binding and activation by endogenous hormones and phytoestrogens in two species of rhinoceros; southern white and greater one-horned. We have found many of these techniques valuable and practical in species where access to research subjects and/or tissues is limited due to their conservation status. From cell-free, competitive binding assays to full-length receptor activation assays; each technique has strengths and weaknesses related to cost, sensitivity, complexity of the protocols, and relevance to in vivo signaling. We then present a novel approach, in which receptor activation assays are performed in primary cell lines derived from the species of interest, to minimize the artifacts of traditional heterologous expression systems. Finally, we speculate on the promise of next generation sequencing and transcriptome profiling as tools for characterizing hormone signaling in threatened and endangered species. Copyright © 2014 Elsevier Inc. All rights reserved.

WildSpan: mining structured motifs from protein sequences

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Chen Chien-Yu

2011-03-01

Full Text Available Abstract Background Automatic extraction of motifs from biological sequences is an important research problem in study of molecular biology. For proteins, it is desired to discover sequence motifs containing a large number of wildcard symbols, as the residues associated with functional sites are usually largely separated in sequences. Discovering such patterns is time-consuming because abundant combinations exist when long gaps (a gap consists of one or more successive wildcards are considered. Mining algorithms often employ constraints to narrow down the search space in order to increase efficiency. However, improper constraint models might degrade the sensitivity and specificity of the motifs discovered by computational methods. We previously proposed a new constraint model to handle large wildcard regions for discovering functional motifs of proteins. The patterns that satisfy the proposed constraint model are called W-patterns. A W-pattern is a structured motif that groups motif symbols into pattern blocks interleaved with large irregular gaps. Considering large gaps reflects the fact that functional residues are not always from a single region of protein sequences, and restricting motif symbols into clusters corresponds to the observation that short motifs are frequently present within protein families. To efficiently discover W-patterns for large-scale sequence annotation and function prediction, this paper first formally introduces the problem to solve and proposes an algorithm named WildSpan (sequential pattern mining across large wildcard regions that incorporates several pruning strategies to largely reduce the mining cost. Results WildSpan is shown to efficiently find W-patterns containing conserved residues that are far separated in sequences. We conducted experiments with two mining strategies, protein-based and family-based mining, to evaluate the usefulness of W-patterns and performance of WildSpan. The protein-based mining mode

Third-Generation Sequencing and Analysis of Four Complete Pig Liver Esterase Gene Sequences in Clones Identified by Screening BAC Library.

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Zhou, Qiongqiong; Sun, Wenjuan; Liu, Xiyan; Wang, Xiliang; Xiao, Yuncai; Bi, Dingren; Yin, Jingdong; Shi, Deshi

2016-01-01

Pig liver carboxylesterase (PLE) gene sequences in GenBank are incomplete, which has led to difficulties in studying the genetic structure and regulation mechanisms of gene expression of PLE family genes. The aim of this study was to obtain and analysis of complete gene sequences of PLE family by screening from a Rongchang pig BAC library and third-generation PacBio gene sequencing. After a number of existing incomplete PLE isoform gene sequences were analysed, primers were designed based on conserved regions in PLE exons, and the whole pig genome used as a template for Polymerase chain reaction (PCR) amplification. Specific primers were then selected based on the PCR amplification results. A three-step PCR screening method was used to identify PLE-positive clones by screening a Rongchang pig BAC library and PacBio third-generation sequencing was performed. BLAST comparisons and other bioinformatics methods were applied for sequence analysis. Five PLE-positive BAC clones, designated BAC-10, BAC-70, BAC-75, BAC-119 and BAC-206, were identified. Sequence analysis yielded the complete sequences of four PLE genes, PLE1, PLE-B9, PLE-C4, and PLE-G2. Complete PLE gene sequences were defined as those containing regulatory sequences, exons, and introns. It was found that, not only did the PLE exon sequences of the four genes show a high degree of homology, but also that the intron sequences were highly similar. Additionally, the regulatory region of the genes contained two 720bps reverse complement sequences that may have an important function in the regulation of PLE gene expression. This is the first report to confirm the complete sequences of four PLE genes. In addition, the study demonstrates that each PLE isoform is encoded by a single gene and that the various genes exhibit a high degree of sequence homology, suggesting that the PLE family evolved from a single ancestral gene. Obtaining the complete sequences of these PLE genes provides the necessary foundation for

Conservation businesses and conservation planning in a biological diversity hotspot.

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Di Minin, Enrico; Macmillan, Douglas Craig; Goodman, Peter Styan; Escott, Boyd; Slotow, Rob; Moilanen, Atte

2013-08-01

The allocation of land to biological diversity conservation competes with other land uses and the needs of society for development, food, and extraction of natural resources. Trade-offs between biological diversity conservation and alternative land uses are unavoidable, given the realities of limited conservation resources and the competing demands of society. We developed a conservation-planning assessment for the South African province of KwaZulu-Natal, which forms the central component of the Maputaland-Pondoland-Albany biological diversity hotspot. Our objective was to enhance biological diversity protection while promoting sustainable development and providing spatial guidance in the resolution of potential policy conflicts over priority areas for conservation at risk of transformation. The conservation-planning assessment combined spatial-distribution models for 646 conservation features, spatial economic-return models for 28 alternative land uses, and spatial maps for 4 threats. Nature-based tourism businesses were competitive with other land uses and could provide revenues of >US$60 million/year to local stakeholders and simultaneously help meeting conservation goals for almost half the conservation features in the planning region. Accounting for opportunity costs substantially decreased conflicts between biological diversity, agricultural use, commercial forestry, and mining. Accounting for economic benefits arising from conservation and reducing potential policy conflicts with alternative plans for development can provide opportunities for successful strategies that combine conservation and sustainable development and facilitate conservation action. © 2013 Society for Conservation Biology.

Murine mammary tumor virus pol-related sequences in human DNA: characterization and sequence comparison with the complete murine mammary tumor virus pol gene

International Nuclear Information System (INIS)

Deen, K.C.; Sweet, R.W.

1986-01-01

Sequences in the human genome with homology to the murine mammary tumor virus (MMTV) pol gene were isolated from a human phage library. Ten clones with extensive pol homology were shown to define five separate loci. These loci share common sequences immediately adjacent to the pol-like segments and, in addition, contain a related repeat element which bounds this region. This organization is suggestive of a proviral structure. The authors estimate that the human genome contains 30 to 40 copies of these pol-related sequences. The pol region of one of the cloned segments (HM16) and the complete MMTV pol gene were sequenced and compared. The nucleotide homology between these pol sequences is 52% and is concentrated in the terminal regions. The MMTV pol gene contains a single long open reading frame encoding 899 amino acids and is demarcated from the partially overlapping putative gag gene by termination codons and a shift in translational reading frame. The pol sequence of HM16 is multiply terminated but does contain open reading frames which encode 370, 105, and 112 amino acids residues in separate reading frames. The authors deduced a composite pol protein sequence for HM16 by aligning it to the MMTV pol gene and then compared these sequences with other retroviral pol protein sequences. Conserved sequences occur in both the amino and carboxyl regions which lie within the polymerase and endonuclease domains of pol, respectively

Structural and functional conservation of CLEC-2 with the species-specific regulation of transcript expression in evolution.

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Wang, Lan; Ren, Shifang; Zhu, Haiyan; Zhang, Dongmei; Hao, Yuqing; Ruan, Yuanyuan; Zhou, Lei; Lee, Chiayu; Qiu, Lin; Yun, Xiaojing; Xie, Jianhui

2012-08-01

CLEC-2 was first identified by sequence similarity to C-type lectin-like molecules with immune functions and has been reported as a receptor for the platelet-aggregating snake venom toxin rhodocytin and the endogenous sialoglycoprotein podoplanin. Recent researches indicate that CLEC-2-deficient mice were lethal at the embryonic stage associated with disorganized and blood-filled lymphatic vessels and severe edema. In view of a necessary role of CLEC-2 in the individual development, it is of interest to investigate its phylogenetic homology and highly conserved functional regions. In this work, we reported that CLEC-2 from different species holds with an extraordinary conservation by sequence alignment and phylogenetic tree analysis. The functional structures including N-linked oligosaccharide sites and ligand-binding domain implement a structural and functional conservation in a variety of species. The glycosylation sites (N120 and N134) are necessary for the surface expression CLEC-2. CLEC-2 from different species possesses the binding activity of mouse podoplanin. Nevertheless, the expression of CLEC-2 is regulated with a species-specific manner. The alternative splicing of pre-mRNA, a regulatory mechanism of gene expression, and the binding sites on promoter for several key transcription factors vary between different species. Therefore, CLEC-2 shares high sequence homology and functional identity. However the transcript expression might be tightly regulated by different mechanisms in evolution.

[Identification of new conserved and variable regions in the 16S rRNA gene of acetic acid bacteria and acetobacteraceae family].

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Chakravorty, S; Sarkar, S; Gachhui, R

2015-01-01

The Acetobacteraceae family of the class Alpha Proteobacteria is comprised of high sugar and acid tolerant bacteria. The Acetic Acid Bacteria are the economically most significant group of this family because of its association with food products like vinegar, wine etc. Acetobacteraceae are often hard to culture in laboratory conditions and they also maintain very low abundances in their natural habitats. Thus identification of the organisms in such environments is greatly dependent on modern tools of molecular biology which require a thorough knowledge of specific conserved gene sequences that may act as primers and or probes. Moreover unconserved domains in genes also become markers for differentiating closely related genera. In bacteria, the 16S rRNA gene is an ideal candidate for such conserved and variable domains. In order to study the conserved and variable domains of the 16S rRNA gene of Acetic Acid Bacteria and the Acetobacteraceae family, sequences from publicly available databases were aligned and compared. Near complete sequences of the gene were also obtained from Kombucha tea biofilm, a known Acetobacteraceae family habitat, in order to corroborate the domains obtained from the alignment studies. The study indicated that the degree of conservation in the gene is significantly higher among the Acetic Acid Bacteria than the whole Acetobacteraceae family. Moreover it was also observed that the previously described hypervariable regions V1, V3, V5, V6 and V7 were more or less conserved in the family and the spans of the variable regions are quite distinct as well.

The PRC2-binding long non-coding RNAs in human and mouse genomes are associated with predictive sequence features

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Tu, Shiqi; Yuan, Guo-Cheng; Shao, Zhen

2017-01-01

Recently, long non-coding RNAs (lncRNAs) have emerged as an important class of molecules involved in many cellular processes. One of their primary functions is to shape epigenetic landscape through interactions with chromatin modifying proteins. However, mechanisms contributing to the specificity of such interactions remain poorly understood. Here we took the human and mouse lncRNAs that were experimentally determined to have physical interactions with Polycomb repressive complex 2 (PRC2), and systematically investigated the sequence features of these lncRNAs by developing a new computational pipeline for sequences composition analysis, in which each sequence is considered as a series of transitions between adjacent nucleotides. Through that, PRC2-binding lncRNAs were found to be associated with a set of distinctive and evolutionarily conserved sequence features, which can be utilized to distinguish them from the others with considerable accuracy. We further identified fragments of PRC2-binding lncRNAs that are enriched with these sequence features, and found they show strong PRC2-binding signals and are more highly conserved across species than the other parts, implying their functional importance.

Getting complete genomes from complex samples using nanopore sequencing

DEFF Research Database (Denmark)

Kirkegaard, Rasmus Hansen; Karst, Søren Michael; Albertsen, Mads

Background Short read DNA sequencing and metagenomic binning workflows have made it possible to extract bacterial genome bins from environmental microbial samples containing hundreds to thousands of different species. However, these genome bins often do not represent complete genomes......, as they are mostly fragmented, incomplete and often contaminated with foreign DNA. The value of these `draft genomes` have limited, lasting value to the scientific community, as gene synteny is broken and there is some uncertainty of what is missing1. The genetic material most often missed is important multi......-copy and/or conserved marker genes such as the 16S rRNA gene, as sequence micro-heterogeneity prevents assembly of these genes in the de novo assembly. However, long read sequencing technologies are emerging promising an end to fragmented genome assemblies2. Experimental design We extracted DNA from a full...

Highly conserved intragenic HSV-2 sequences: Results from next-generation sequencing of HSV-2 UL and US regions from genital swabs collected from 3 continents.

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Johnston, Christine; Magaret, Amalia; Roychoudhury, Pavitra; Greninger, Alexander L; Cheng, Anqi; Diem, Kurt; Fitzgibbon, Matthew P; Huang, Meei-Li; Selke, Stacy; Lingappa, Jairam R; Celum, Connie; Jerome, Keith R; Wald, Anna; Koelle, David M

2017-10-01

Understanding the variability in circulating herpes simplex virus type 2 (HSV-2) genomic sequences is critical to the development of HSV-2 vaccines. Genital lesion swabs containing ≥ 10 7 log 10 copies HSV DNA collected from Africa, the USA, and South America underwent next-generation sequencing, followed by K-mer based filtering and de novo genomic assembly. Sites of heterogeneity within coding regions in unique long and unique short (U L _U S ) regions were identified. Phylogenetic trees were created using maximum likelihood reconstruction. Among 46 samples from 38 persons, 1468 intragenic base-pair substitutions were identified. The maximum nucleotide distance between strains for concatenated U L_ U S segments was 0.4%. Phylogeny did not reveal geographic clustering. The most variable proteins had non-synonymous mutations in < 3% of amino acids. Unenriched HSV-2 DNA can undergo next-generation sequencing to identify intragenic variability. The use of clinical swabs for sequencing expands the information that can be gathered directly from these specimens. Copyright © 2017 Elsevier Inc. All rights reserved.

Statistical approaches to use a model organism for regulatory sequences annotation of newly sequenced species.

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Pietro Liò

Full Text Available A major goal of bioinformatics is the characterization of transcription factors and the transcriptional programs they regulate. Given the speed of genome sequencing, we would like to quickly annotate regulatory sequences in newly-sequenced genomes. In such cases, it would be helpful to predict sequence motifs by using experimental data from closely related model organism. Here we present a general algorithm that allow to identify transcription factor binding sites in one newly sequenced species by performing Bayesian regression on the annotated species. First we set the rationale of our method by applying it within the same species, then we extend it to use data available in closely related species. Finally, we generalise the method to handle the case when a certain number of experiments, from several species close to the species on which to make inference, are available. In order to show the performance of the method, we analyse three functionally related networks in the Ascomycota. Two gene network case studies are related to the G2/M phase of the Ascomycota cell cycle; the third is related to morphogenesis. We also compared the method with MatrixReduce and discuss other types of validation and tests. The first network is well known and provides a biological validation test of the method. The two cell cycle case studies, where the gene network size is conserved, demonstrate an effective utility in annotating new species sequences using all the available replicas from model species. The third case, where the gene network size varies among species, shows that the combination of information is less powerful but is still informative. Our methodology is quite general and could be extended to integrate other high-throughput data from model organisms.

Conservation of the glycoprotein B homologs of the Kaposi’s sarcoma-associated herpesvirus (KSHV/HHV8) and Old World primate rhadinoviruses of chimpanzees and macaques

Science.gov (United States)

Bruce, A. Gregory; Horst, Jeremy A.; Rose, Timothy M.

2016-01-01

The envelope-associated glycoprotein B (gB) is highly conserved within the Herpesviridae and plays a critical role in viral entry. We analyzed the evolutionary conservation of sequence and structural motifs within the Kaposi’s sarcoma-associated herpesvirus (KSHV) gB and homologs of Old World primate rhadinoviruses belonging to the distinct RV1 and RV2 rhadinovirus lineages. In addition to gB homologs of rhadinoviruses infecting the pig-tailed and rhesus macaques, we cloned and sequenced gB homologs of RV1 and RV2 rhadinoviruses infecting chimpanzees. A structural model of the KSHV gB was determined, and functional motifs and sequence variants were mapped to the model structure. Conserved domains and motifs were identified, including an “RGD” motif that plays a critical role in KSHV binding and entry through the cellular integrin αVβ3. The RGD motif was only detected in RV1 rhadinoviruses suggesting an important difference in cell tropism between the two rhadinovirus lineages. PMID:27070755

Conserved family of glycerol kinase loci in Drosophila melanogaster

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Martinez Agosto, Julian A.; McCabe, Edward R.B.

2009-01-01

Glycerol kinase (GK) is an enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol, the rate-limiting step in glycerol utilization. We analyzed the genome of the model organism Drosophila melanogaster and identified five GK orthologs, including two loci with sequence homology to the mammalian Xp21 GK protein. Using a combination of sequence analysis and evolutionary comparisons of orthologs between species, we characterized functional domains in the protein required for GK activity. Our findings include additional conserved domains that suggest novel nuclear and mitochondrial functions for glycerol kinase in apoptosis and transcriptional regulation. Investigation of GK function in Drosophila will inform us about the role of this enzyme in development and will provide us with a tool to examine genetic modifiers of human metabolic disorders. PMID:16545593

Comparative mtDNA analyses of three sympatric macropodids from a conservation area on the Huon Peninsula, Papua New Guinea.

Science.gov (United States)

McGreevy, Thomas J; Dabek, Lisa; Husband, Thomas P

2016-07-01

Matschie's tree kangaroo (Dendrolagus matschiei), New Guinea pademelon (Thylogale browni), and small dorcopsis (Dorcopsulus vanheurni) are sympatric macropodid taxa, of conservation concern, that inhabit the Yopno-Urawa-Som (YUS) Conservation Area on the Huon Peninsula, Papua New Guinea. We sequenced three partial mitochondrial DNA (mtDNA) genes from the three taxa to (i) investigate network structure; and (ii) identify conservation units within the YUS Conservation Area. All three taxa displayed a similar pattern in the spatial distribution of their mtDNA haplotypes and the Urawa and Som rivers on the Huon may have acted as a barrier to maternal gene flow. Matschie's tree kangaroo and New Guinea pademelon within the YUS Conservation Area should be managed as single conservation units because mtDNA nucleotides were not fixed for a given geographic area. However, two distinct conservation units were identified for small dorcopsis from the two different mountain ranges within the YUS Conservation Area.

Network evolution: rewiring and signatures of conservation in signaling.

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Mark G F Sun

Full Text Available The analysis of network evolution has been hampered by limited availability of protein interaction data for different organisms. In this study, we investigate evolutionary mechanisms in Src Homology 3 (SH3 domain and kinase interaction networks using high-resolution specificity profiles. We constructed and examined networks for 23 fungal species ranging from Saccharomyces cerevisiae to Schizosaccharomyces pombe. We quantify rates of different rewiring mechanisms and show that interaction change through binding site evolution is faster than through gene gain or loss. We found that SH3 interactions evolve swiftly, at rates similar to those found in phosphoregulation evolution. Importantly, we show that interaction changes are sufficiently rapid to exhibit saturation phenomena at the observed timescales. Finally, focusing on the SH3 interaction network, we observe extensive clustering of binding sites on target proteins by SH3 domains and a strong correlation between the number of domains that bind a target protein (target in-degree and interaction conservation. The relationship between in-degree and interaction conservation is driven by two different effects, namely the number of clusters that correspond to interaction interfaces and the number of domains that bind to each cluster leads to sequence specific conservation, which in turn results in interaction conservation. In summary, we uncover several network evolution mechanisms likely to generalize across peptide recognition modules.

Adhesive proteins of stalked and acorn barnacles display homology with low sequence similarities.

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Jaimie-Leigh Jonker

Full Text Available Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins 'sticky' has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes. It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa. Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7-16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes. Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18-26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa are more conserved within barnacles than others (20 kDa.

Molecular genetic characterization of the RD-114 gene family of endogenous feline retroviral sequences.

Science.gov (United States)

Reeves, R H; O'Brien, S J

1984-01-01

RD-114 is a replication-competent, xenotropic retrovirus which is homologous to a family of moderately repetitive DNA sequences present at ca. 20 copies in the normal cellular genome of domestic cats. To examine the extent and character of genomic divergence of the RD-114 gene family as well as to assess their positional association within the cat genome, we have prepared a series of molecular clones of endogenous RD-114 DNA segments from a genomic library of cat cellular DNA. Their restriction endonuclease maps were compared with each other as well as to that of the prototype-inducible RD-114 which was molecularly cloned from a chronically infected human cell line. The endogenous sequences analyzed were similar to each other in that they were colinear with RD-114 proviral DNA, were bounded by long terminal redundancies, and conserved many restriction sites in the gag and pol regions. However, the env regions of many of the sequences examined were substantially deleted. Several of the endogenous RD-114 genomes contained a novel envelope sequence which was unrelated to the env gene of the prototype RD-114 env gene but which, like RD-114 and endogenous feline leukemia virus provirus, was found only in species of the genus Felis, and not in other closely related Felidae genera. The endogenous RD-114 sequences each had a distinct cellular flank which indicates that these sequences are not tandem but dispersed nonspecifically throughout the genome. Southern analysis of cat cellular DNA confirmed the conclusions about conserved restriction sites in endogenous sequences and indicated that a single locus may be responsible for the production of the major inducible form of RD-114. Images PMID:6090693

Isolation of BAC Clones Containing Conserved Genes from Libraries of Three Distantly Related Moths: A Useful Resource for Comparative Genomics of Lepidoptera

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Yuji Yasukochi

2011-01-01

Full Text Available Lepidoptera, butterflies and moths, is the second largest animal order and includes numerous agricultural pests. To facilitate comparative genomics in Lepidoptera, we isolated BAC clones containing conserved and putative single-copy genes from libraries of three pests, Heliothis virescens, Ostrinia nubilalis, and Plutella xylostella, harboring the haploid chromosome number, =31, which are not closely related with each other or with the silkworm, Bombyx mori, (=28, the sequenced model lepidopteran. A total of 108–184 clones representing 101–182 conserved genes were isolated for each species. For 79 genes, clones were isolated from more than two species, which will be useful as common markers for analysis using fluorescence in situ hybridization (FISH, as well as for comparison of genome sequence among multiple species. The PCR-based clone isolation method presented here is applicable to species which lack a sequenced genome but have a significant collection of cDNA or EST sequences.

Genomic 3' terminal sequence comparison of three isolates of rabbit haemorrhagic disease virus.

Science.gov (United States)

Milton, I D; Vlasak, R; Nowotny, N; Rodak, L; Carter, M J

1992-05-15

Comparison of sequence data is necessary in older to investigate virus origins, identify features common to virulent strains, and characterize genomic organization within virus families. A virulent caliciviral disease of rabbits recently emerged in China. We have sequenced 1100 bases from the 3' ends of two independent European isolates of this virus, and compared these with previously determined calicivirus sequences. Rabbit caliciviruses were closely related, despite the different countries in which isolation was made. This supports the rapid spread of a new virus across Europe. The capsid protein sequences of these rabbit viruses differ markedly from those determined for feline calicivirus, but a hypothetical 3' open reading frame is relatively well conserved between the caliciviruses of these two different hosts and argues for a functional role.

Conservation genomics of the endangered Burmese roofed turtle.

Science.gov (United States)

Çilingir, F Gözde; Rheindt, Frank E; Garg, Kritika M; Platt, Kalyar; Platt, Steven G; Bickford, David P

2017-12-01

The Burmese roofed turtle (Batagur trivittata) is one of the world's most endangered turtles. Only one wild population remains in Myanmar. There are thought to be 12 breeding turtles in the wild. Conservation efforts for the species have raised >700 captive turtles since 2002, predominantly from eggs collected in the wild. We collected tissue samples from 445 individuals (approximately 40% of the turtles' remaining global population), applied double-digest restriction-site associated DNA sequencing (ddRAD-Seq), and obtained approximately 1500 unlinked genome-wide single nucleotide polymorphisms. Individuals fell into 5 distinct genetic clusters, 4 of which represented full-sib families. We inferred a low effective population size (≤10 individuals) but did not detect signs of severe inbreeding, possibly because the population bottleneck occurred recently. Two groups of 30 individuals from the captive pool that were the most genetically diverse were reintroduced to the wild, leading to an increase in the number of fertile eggs (n = 27) in the wild. Another 25 individuals, selected based on the same criteria, were transferred to the Singapore Zoo as an assurance colony. Our study demonstrates that the research-to-application gap in conservation can be bridged through application of cutting-edge genomic methods. © 2017 Society for Conservation Biology.

A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities.

Science.gov (United States)

Bastien, Olivier; Ortet, Philippe; Roy, Sylvaine; Maréchal, Eric

2005-03-10

Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons) and be the basis for a novel method of consistent and stable phylogenetic reconstruction. We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space) and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP) allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities

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Maréchal Eric

2005-03-01

Full Text Available Abstract Background Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons and be the basis for a novel method of consistent and stable phylogenetic reconstruction. Results We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. Conclusion The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

Primary structure and localization of a conserved immunogenic Plasmodium falciparum glutamate rich protein (GLURP) expressed in both the preerythrocytic and erythrocytic stages of the vertebrate life cycle

DEFF Research Database (Denmark)

Borre, M B; Dziegiel, M; Høgh, B

1991-01-01

A gene coding for a 220-kDa glutamate rich protein (GLURP), an exoantigen of Plasmodium falciparum, was isolated and its nucleotide sequence was determined. The deduced amino acid sequence contains 2 repeat regions. The sequence of one of these was shown to be conserved among geographically...

Ubiquitin--conserved protein or selfish gene?

Science.gov (United States)

Catic, André; Ploegh, Hidde L

2005-11-01

The posttranslational modifier ubiquitin is encoded by a multigene family containing three primary members, which yield the precursor protein polyubiquitin and two ubiquitin moieties, Ub(L40) and Ub(S27), that are fused to the ribosomal proteins L40 and S27, respectively. The gene encoding polyubiquitin is highly conserved and, until now, those encoding Ub(L40) and Ub(S27) have been generally considered to be equally invariant. The evolution of the ribosomal ubiquitin moieties is, however, proving to be more dynamic. It seems that the genes encoding Ub(L40) and Ub(S27) are actively maintained by homologous recombination with the invariant polyubiquitin locus. Failure to recombine leads to deterioration of the sequence of the ribosomal ubiquitin moieties in several phyla, although this deterioration is evidently constrained by the structural requirements of the ubiquitin fold. Only a few amino acids in ubiquitin are vital for its function, and we propose that conservation of all three ubiquitin genes is driven not only by functional properties of the ubiquitin protein, but also by the propensity of the polyubiquitin locus to act as a 'selfish gene'.

The complete chloroplast genome sequence of Dodonaea viscosa: comparative and phylogenetic analyses.

Science.gov (United States)

Saina, Josphat K; Gichira, Andrew W; Li, Zhi-Zhong; Hu, Guang-Wan; Wang, Qing-Feng; Liao, Kuo

2018-02-01

The plant chloroplast (cp) genome is a highly conserved structure which is beneficial for evolution and systematic research. Currently, numerous complete cp genome sequences have been reported due to high throughput sequencing technology. However, there is no complete chloroplast genome of genus Dodonaea that has been reported before. To better understand the molecular basis of Dodonaea viscosa chloroplast, we used Illumina sequencing technology to sequence its complete genome. The whole length of the cp genome is 159,375 base pairs (bp), with a pair of inverted repeats (IRs) of 27,099 bp separated by a large single copy (LSC) 87,204 bp, and small single copy (SSC) 17,972 bp. The annotation analysis revealed a total of 115 unique genes of which 81 were protein coding, 30 tRNA, and four ribosomal RNA genes. Comparative genome analysis with other closely related Sapindaceae members showed conserved gene order in the inverted and single copy regions. Phylogenetic analysis clustered D. viscosa with other species of Sapindaceae with strong bootstrap support. Finally, a total of 249 SSRs were detected. Moreover, a comparison of the synonymous (Ks) and nonsynonymous (Ka) substitution rates in D. viscosa showed very low values. The availability of cp genome reported here provides a valuable genetic resource for comprehensive further studies in genetic variation, taxonomy and phylogenetic evolution of Sapindaceae family. In addition, SSR markers detected will be used in further phylogeographic and population structure studies of the species in this genus.

Implication of the cause of differences in 3D structures of proteins with high sequence identity based on analyses of amino acid sequences and 3D structures.

Science.gov (United States)

Matsuoka, Masanari; Sugita, Masatake; Kikuchi, Takeshi

2014-09-18

Proteins that share a high sequence homology while exhibiting drastically different 3D structures are investigated in this study. Recently, artificial proteins related to the sequences of the GA and IgG binding GB domains of human serum albumin have been designed. These artificial proteins, referred to as GA and GB, share 98% amino acid sequence identity but exhibit different 3D structures, namely, a 3α bundle versus a 4β + α structure. Discriminating between their 3D structures based on their amino acid sequences is a very difficult problem. In the present work, in addition to using bioinformatics techniques, an analysis based on inter-residue average distance statistics is used to address this problem. It was hard to distinguish which structure a given sequence would take only with the results of ordinary analyses like BLAST and conservation analyses. However, in addition to these analyses, with the analysis based on the inter-residue average distance statistics and our sequence tendency analysis, we could infer which part would play an important role in its structural formation. The results suggest possible determinants of the different 3D structures for sequences with high sequence identity. The possibility of discriminating between the 3D structures based on the given sequences is also discussed.

Regulation of G-protein coupled receptor traffic by an evolutionary conserved hydrophobic signal.

Science.gov (United States)

Angelotti, Tim; Daunt, David; Shcherbakova, Olga G; Kobilka, Brian; Hurt, Carl M

2010-04-01

Plasma membrane (PM) expression of G-protein coupled receptors (GPCRs) is required for activation by extracellular ligands; however, mechanisms that regulate PM expression of GPCRs are poorly understood. For some GPCRs, such as alpha2c-adrenergic receptors (alpha(2c)-ARs), heterologous expression in non-native cells results in limited PM expression and extensive endoplasmic reticulum (ER) retention. Recently, ER export/retentions signals have been proposed to regulate cellular trafficking of several GPCRs. By utilizing a chimeric alpha(2a)/alpha(2c)-AR strategy, we identified an evolutionary conserved hydrophobic sequence (ALAAALAAAAA) in the extracellular amino terminal region that is responsible in part for alpha(2c)-AR subtype-specific trafficking. To our knowledge, this is the first luminal ER retention signal reported for a GPCR. Removal or disruption of the ER retention signal dramatically increased PM expression and decreased ER retention. Conversely, transplantation of this hydrophobic sequence into alpha(2a)-ARs reduced their PM expression and increased ER retention. This evolutionary conserved hydrophobic trafficking signal within alpha(2c)-ARs serves as a regulator of GPCR trafficking.

Cloning and sequencing of the gene for human β-casein

International Nuclear Information System (INIS)

Loennerdal, B.; Bergstroem, S.; Andersson, Y.; Hialmarsson, K.; Sundgyist, A.; Hernell, O.

1990-01-01

Human β-casein is a major protein in human milk. This protein is part of the casein micelle and has been suggested to have several physiological functions in the newborn. Since there is limited information on βcasein and the factors that affect its concentration in human milk, the authors have isolated and sequenced the gene for this protein. A human mammary gland cDNA library (Clontech) in gt 11 was screened by plaque hy-hybridization using a 42-mer synthetic 32 p-labelled oligo-nucleotide. Positive clones were identified and isolated, DNA was prepared and the gene isolated by cleavage with EcoR1. Following subcloning (PUC18), restriction mapping and Southern blotting, DNA for sequencing was prepared. The gene was sequenced by the dideoxy method. Human β-casein has 212 amino acids and the amino acid sequence deducted from the nucleotide sequence is to 91% identical to the published sequence for human β-casein show a high degree of conservation at the leader peptide and the highly phosphorylated sequences, but also deletions and divergence at several positions. These results provide insight into the structure of the human β-casein gene and will facilitate studies on factors affecting its expression

A functional analysis of the spacer of V(DJ recombination signal sequences.

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Alfred Ian Lee

2003-10-01

Full Text Available During lymphocyte development, V(DJ recombination assembles antigen receptor genes from component V, D, and J gene segments. These gene segments are flanked by a recombination signal sequence (RSS, which serves as the binding site for the recombination machinery. The murine Jbeta2.6 gene segment is a recombinationally inactive pseudogene, but examination of its RSS reveals no obvious reason for its failure to recombine. Mutagenesis of the Jbeta2.6 RSS demonstrates that the sequences of the heptamer, nonamer, and spacer are all important. Strikingly, changes solely in the spacer sequence can result in dramatic differences in the level of recombination. The subsequent analysis of a library of more than 4,000 spacer variants revealed that spacer residues of particular functional importance are correlated with their degree of conservation. Biochemical assays indicate distinct cooperation between the spacer and heptamer/nonamer along each step of the reaction pathway. The results suggest that the spacer serves not only to ensure the appropriate distance between the heptamer and nonamer but also regulates RSS activity by providing additional RAG:RSS interaction surfaces. We conclude that while RSSs are defined by a "digital" requirement for absolutely conserved nucleotides, the quality of RSS function is determined in an "analog" manner by numerous complex interactions between the RAG proteins and the less-well conserved nucleotides in the heptamer, the nonamer, and, importantly, the spacer. Those modulatory effects are accurately predicted by a new computational algorithm for "RSS information content." The interplay between such binary and multiplicative modes of interactions provides a general model for analyzing protein-DNA interactions in various biological systems.

DNA sequence explains seemingly disordered methylation levels in partially methylated domains of Mammalian genomes.

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Dimos Gaidatzis

2014-02-01

Full Text Available For the most part metazoan genomes are highly methylated and harbor only small regions with low or absent methylation. In contrast, partially methylated domains (PMDs, recently discovered in a variety of cell lines and tissues, do not fit this paradigm as they show partial methylation for large portions (20%-40% of the genome. While in PMDs methylation levels are reduced on average, we found that at single CpG resolution, they show extensive variability along the genome outside of CpG islands and DNase I hypersensitive sites (DHS. Methylation levels range from 0% to 100% in a roughly uniform fashion with only little similarity between neighboring CpGs. A comparison of various PMD-containing methylomes showed that these seemingly disordered states of methylation are strongly conserved across cell types for virtually every PMD. Comparative sequence analysis suggests that DNA sequence is a major determinant of these methylation states. This is further substantiated by a purely sequence based model which can predict 31% (R(2 of the variation in methylation. The model revealed CpG density as the main driving feature promoting methylation, opposite to what has been shown for CpG islands, followed by various dinucleotides immediately flanking the CpG and a minor contribution from sequence preferences reflecting nucleosome positioning. Taken together we provide a reinterpretation for the nucleotide-specific methylation levels observed in PMDs, demonstrate their conservation across tissues and suggest that they are mainly determined by specific DNA sequence features.

Complete mitochondrial genome sequences from five Eimeria species (Apicomplexa; Coccidia; Eimeriidae) infecting domestic turkeys.

Science.gov (United States)

Ogedengbe, Mosun E; El-Sherry, Shiem; Whale, Julia; Barta, John R

2014-07-17

Clinical and subclinical coccidiosis is cosmopolitan and inflicts significant losses to the poultry industry globally. Seven named Eimeria species are responsible for coccidiosis in turkeys: Eimeria dispersa; Eimeria meleagrimitis; Eimeria gallopavonis; Eimeria meleagridis; Eimeria adenoeides; Eimeria innocua; and, Eimeria subrotunda. Although attempts have been made to characterize these parasites molecularly at the nuclear 18S rDNA and ITS loci, the maternally-derived and mitotically replicating mitochondrial genome may be more suited for species level molecular work; however, only limited sequence data are available for Eimeria spp. infecting turkeys. The purpose of this study was to sequence and annotate the complete mitochondrial genomes from 5 Eimeria species that commonly infect the domestic turkey (Meleagris gallopavo). Six single-oocyst derived cultures of five Eimeria species infecting turkeys were PCR-amplified and sequenced completely prior to detailed annotation. Resulting sequences were aligned and used in phylogenetic analyses (BI, ML, and MP) that included complete mitochondrial genomes from 16 Eimeria species or concatenated CDS sequences from each genome. Complete mitochondrial genome sequences were obtained for Eimeria adenoeides Guelph, 6211 bp; Eimeria dispersa Briston, 6238 bp; Eimeria meleagridis USAR97-01, 6212 bp; Eimeria meleagrimitis USMN08-01, 6165 bp; Eimeria gallopavonis Weybridge, 6215 bp; and Eimeria gallopavonis USKS06-01, 6215 bp). The order, orientation and CDS lengths of the three protein coding genes (COI, COIII and CytB) as well as rDNA fragments encoding ribosomal large and small subunit rRNA were conserved among all sequences. Pairwise sequence identities between species ranged from 88.1% to 98.2%; sequence variability was concentrated within CDS or between rDNA fragments (where indels were common). No phylogenetic reconstruction supported monophyly of Eimeria species infecting turkeys; Eimeria dispersa may have arisen

Complete Genome Sequences of Mycobacteriophages Clautastrophe, Kingsolomon, Krypton555, and Nicholas

OpenAIRE

Chung, Hui-Min; D’Elia, Tom; Ross, Joseph F.; Alvarado, Samuel M.; Brantley, Molly-Catherine; Bricker, Lydia P.; Butler, Courtney R.; Crist, Carson; Dane, Julia M.; Farran, Brett W.; Hobbs, Sierra; Lapak, Michelle; Lovell, Conner; Ludergnani, Nicholas; McMullen, Allison

2017-01-01

ABSTRACT We report here the complete genome sequences of four subcluster L3 mycobacteriophages newly isolated from soil samples, using Mycobacterium smegmatis mc2155 as the host. Comparative genomic analyses with four previously described subcluster L3 phages reveal strong nucleotide similarity and gene conservation, with several large insertions/deletions near their right genome ends.

Genomic analysis of expressed sequence tags in American black bear Ursus americanus

Science.gov (United States)

2010-01-01

Background Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus). Results Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference. We identified 18 genes, involved in functions such as lipid catabolism, cell cycle, and vesicle-mediated transport, that are showing rapid evolution in the bear lineage Three genes, Phospholamban (PLN), cysteine glycine-rich protein 3 (CSRP3) and Troponin I type 3 (TNNI3), are related to heart contraction, and defects in these genes in humans lead to heart disease. Two genes, biphenyl hydrolase-like (BPHL) and CSRP3, contain positively selected sites in bear. Global analysis of evolution rates of hibernation-related genes in bear showed that they are largely conserved and slowly evolving genes, rather than novel and fast-evolving genes. Conclusion We provide a genomic resource for an important mammalian organism and our study sheds new light on the possible functions and evolution of bear genes. PMID:20338065

Genomic analysis of expressed sequence tags in American black bear Ursus americanus.

Science.gov (United States)

Zhao, Sen; Shao, Chunxuan; Goropashnaya, Anna V; Stewart, Nathan C; Xu, Yichi; Tøien, Øivind; Barnes, Brian M; Fedorov, Vadim B; Yan, Jun

2010-03-26

Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus). Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference. We identified 18 genes, involved in functions such as lipid catabolism, cell cycle, and vesicle-mediated transport, that are showing rapid evolution in the bear lineage Three genes, Phospholamban (PLN), cysteine glycine-rich protein 3 (CSRP3) and Troponin I type 3 (TNNI3), are related to heart contraction, and defects in these genes in humans lead to heart disease. Two genes, biphenyl hydrolase-like (BPHL) and CSRP3, contain positively selected sites in bear. Global analysis of evolution rates of hibernation-related genes in bear showed that they are largely conserved and slowly evolving genes, rather than novel and fast-evolving genes. We provide a genomic resource for an important mammalian organism and our study sheds new light on the possible functions and evolution of bear genes.

Distribution of Ds-like sequences in genomes of cereals

International Nuclear Information System (INIS)

Vershinin, A.V.; Salina, E.A.; Shumnii, V.K.; Svitashev, S.K.

1986-01-01

It has been suggested that insertions of Ds-elements may alter the effectiveness of transcription or translation of the genetic loci and the normal processing of introns and exons, and that they may impair coding frames, etc. The object of the present study was to determine the frequency of occurence of DNA sequences similar to the Ds-controlling elements of mazie (Ds-like sequences) among other representatives of cereals. The conservative feature of the primary structure of transposons from different eukaryotic species served as a basis in this investigation. By means of the ''nick-translation'' reaction with the aid of DNA-polymerase I (alpha- 32 P) dCTP or TTP was introduced into the Ds-element. The specific radioactivity of the preparations obtained was 5 x 10 7 to 1 x 10 8 cpm/gamma. From the results obtained, it is suggested that the genomes of cereals examined contain a collection of Ds-like sequences. The Ds-element may have a significant effect on gene expression in the presence of Ac-like or other sequences, which undergo transposition

Detection of a Usp-like gene in Calotropis procera plant from the de novo assembled genome contigs of the high-throughput sequencing dataset

KAUST Repository

Shokry, Ahmed M.; Al-Karim, Saleh; Ramadan, Ahmed M Ali; Gadallah, Nour; Al-Attas, Sanaa G.; Sabir, Jamal Sabir M; Hassan, Sabah Mohammed; Madkour, Loutfy H.; Bressan, Ray Anthony; Mahfouz, Magdy M.; Bahieldin, Ahmed M.

2014-01-01

acids sequence were identified from the NCBI conserved domain database (CDD) that provide insights into sequence structure/function relationships, as well as domain models imported from a number of external source databases (Pfam, SMART, COG, PRK

Structure-Based Sequence Alignment of the Transmembrane Domains of All Human GPCRs: Phylogenetic, Structural and Functional Implications

Science.gov (United States)

Cvicek, Vaclav; Goddard, William A.; Abrol, Ravinder

2016-01-01

The understanding of G-protein coupled receptors (GPCRs) is undergoing a revolution due to increased information about their signaling and the experimental determination of structures for more than 25 receptors. The availability of at least one receptor structure for each of the GPCR classes, well separated in sequence space, enables an integrated superfamily-wide analysis to identify signatures involving the role of conserved residues, conserved contacts, and downstream signaling in the context of receptor structures. In this study, we align the transmembrane (TM) domains of all experimental GPCR structures to maximize the conserved inter-helical contacts. The resulting superfamily-wide GpcR Sequence-Structure (GRoSS) alignment of the TM domains for all human GPCR sequences is sufficient to generate a phylogenetic tree that correctly distinguishes all different GPCR classes, suggesting that the class-level differences in the GPCR superfamily are encoded at least partly in the TM domains. The inter-helical contacts conserved across all GPCR classes describe the evolutionarily conserved GPCR structural fold. The corresponding structural alignment of the inactive and active conformations, available for a few GPCRs, identifies activation hot-spot residues in the TM domains that get rewired upon activation. Many GPCR mutations, known to alter receptor signaling and cause disease, are located at these conserved contact and activation hot-spot residue positions. The GRoSS alignment places the chemosensory receptor subfamilies for bitter taste (TAS2R) and pheromones (Vomeronasal, VN1R) in the rhodopsin family, known to contain the chemosensory olfactory receptor subfamily. The GRoSS alignment also enables the quantification of the structural variability in the TM regions of experimental structures, useful for homology modeling and structure prediction of receptors. Furthermore, this alignment identifies structurally and functionally important residues in all human GPCRs

Molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer myostatin gene

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Smith-Keune Carolyn

2008-02-01

Full Text Available Abstract Background Myostatin (MSTN is a member of the transforming growth factor-β superfamily that negatively regulates growth of skeletal muscle tissue. The gene encoding for the MSTN peptide is a consolidate candidate for the enhancement of productivity in terrestrial livestock. This gene potentially represents an important target for growth improvement of cultured finfish. Results Here we report molecular characterization, tissue expression and sequence variability of the barramundi (Lates calcarifer MSTN-1 gene. The barramundi MSTN-1 was encoded by three exons 379, 371 and 381 bp in length and translated into a 376-amino acid peptide. Intron 1 and 2 were 412 and 819 bp in length and presented typical GT...AG splicing sites. The upstream region contained cis-regulatory elements such as TATA-box and E-boxes. A first assessment of sequence variability suggested that higher mutation rates are found in the 5' flanking region with several SNP's present in this species. A putative micro RNA target site has also been observed in the 3'UTR (untranslated region and is highly conserved across teleost fish. The deduced amino acid sequence was conserved across vertebrates and exhibited characteristic conserved putative functional residues including a cleavage motif of proteolysis (RXXR, nine cysteines and two glycosilation sites. A qualitative analysis of the barramundi MSTN-1 expression pattern revealed that, in adult fish, transcripts are differentially expressed in various tissues other than skeletal muscles including gill, heart, kidney, intestine, liver, spleen, eye, gonad and brain. Conclusion Our findings provide valuable insights such as sequence variation and genomic information which will aid the further investigation of the barramundi MSTN-1 gene in association with growth. The finding for the first time in finfish MSTN of a miRNA target site in the 3'UTR provides an opportunity for the identification of regulatory mutations on the

Geographic variation, genetic structure, and conservation unit designation in the Larch Mountain salamander (Plethodon larselli).

Science.gov (United States)

R. Steven Wagner; Mark P. Miller; Charles M. Crisafulli; Susan M. Haig

2005-01-01

The Larch Mountain salamander (Plethodon larselli Burns, 1954) is an endemic species in the Pacific northwestern United States facing threats related to habitat destruction. To facilitate development of conservation strategies, we used DNA sequences and RAPDs (random amplified polymorphic DNA) to examine differences among populations of this...

Complete Genome Sequences of Mycobacteriophages Clautastrophe, Kingsolomon, Krypton555, and Nicholas

Science.gov (United States)

Chung, Hui-Min; D’Elia, Tom; Ross, Joseph F.; Alvarado, Samuel M.; Brantley, Molly-Catherine; Bricker, Lydia P.; Butler, Courtney R.; Crist, Carson; Dane, Julia M.; Farran, Brett W.; Hobbs, Sierra; Lapak, Michelle; Lovell, Conner; McMullen, Allison; Mirza, Sohail A.; Thrift, Noah; Vaughan, Donald P.; Worley, Grace; Ejikemeuwa, Amara; Zaw, May; Albritton, Claude F.; Bertrand, Sarah C.; Chaudhry, Shanzay S.; Cheema, Vzair A.; Do, Camilla; Do, Michael L.; Duong, Huyen M.; El-Desoky, Dalia H.; Green, Kelsey M.; Lee, Rhea N.; Thornton, Lauren A.; Vu, James M.; Zahra, Mah Noor; Stoner, Ty H.; Garlena, Rebecca A.; Jacobs-Sera, Deborah; Russell, Daniel A.

2017-01-01

ABSTRACT We report here the complete genome sequences of four subcluster L3 mycobacteriophages newly isolated from soil samples, using Mycobacterium smegmatis mc2155 as the host. Comparative genomic analyses with four previously described subcluster L3 phages reveal strong nucleotide similarity and gene conservation, with several large insertions/deletions near their right genome ends. PMID:29122864

Synaptotagmin gene content of the sequenced genomes

Directory of Open Access Journals (Sweden)

Craxton Molly

2004-07-01

Full Text Available Abstract Background Synaptotagmins exist as a large gene family in mammals. There is much interest in the function of certain family members which act crucially in the regulated synaptic vesicle exocytosis required for efficient neurotransmission. Knowledge of the functions of other family members is relatively poor and the presence of Synaptotagmin genes in plants indicates a role for the family as a whole which is wider than neurotransmission. Identification of the Synaptotagmin genes within completely sequenced genomes can provide the entire Synaptotagmin gene complement of each sequenced organism. Defining the detailed structures of all the Synaptotagmin genes and their encoded products can provide a useful resource for functional studies and a deeper understanding of the evolution of the gene family. The current rapid increase in the number of sequenced genomes from different branches of the tree of life, together with the public deposition of evolutionarily diverse transcript sequences make such studies worthwhile. Results I have compiled a detailed list of the Synaptotagmin genes of Caenorhabditis, Anopheles, Drosophila, Ciona, Danio, Fugu, Mus, Homo, Arabidopsis and Oryza by examining genomic and transcript sequences from public sequence databases together with some transcript sequences obtained by cDNA library screening and RT-PCR. I have compared all of the genes and investigated the relationship between plant Synaptotagmins and their non-Synaptotagmin counterparts. Conclusions I have identified and compared 98 Synaptotagmin genes from 10 sequenced genomes. Detailed comparison of transcript sequences reveals abundant and complex variation in Synaptotagmin gene expression and indicates the presence of Synaptotagmin genes in all animals and land plants. Amino acid sequence comparisons indicate patterns of conservation and diversity in function. Phylogenetic analysis shows the origin of Synaptotagmins in multicellular eukaryotes and their

The formation of a native-like structure containing eight conserved hydrophobic residues is rate limiting in two-state protein folding of ACBP

DEFF Research Database (Denmark)

Kragelund, Birthe Brandt; Osmark, Peter; Neergaard, Thomas B.

1999-01-01

The acyl-coenzyme A-binding proteins (ACBPs) contain 26 highly conserved sequence positions. The majority of these have been mutated in the bovine protein, and their influence on the rate of two-state folding and unfolding has been measured. The results identify eight sequence positions, out of 24...... probed, that are critical for fast productive folding. The residues are all hydrophobic and located in the interface between the N- and C-terminal helices. The results suggest that one specific site dominated by conserved hydrophobic residues forms the structure of the productive rate-determining folding...... step and that a sequential framework model can describe the protein folding reaction....

Expression profiling and comparative sequence derived insights into lipid metabolism

Energy Technology Data Exchange (ETDEWEB)

Callow, Matthew J.; Rubin, Edward M.

2001-12-19

Expression profiling and genomic DNA sequence comparisons are increasingly being applied to the identification and analysis of the genes involved in lipid metabolism. Not only has genome-wide expression profiling aided in the identification of novel genes involved in important processes in lipid metabolism such as sterol efflux, but the utilization of information from these studies has added to our understanding of the regulation of pathways participating in the process. Coupled with these gene expression studies, cross species comparison, searching for sequences conserved through evolution, has proven to be a powerful tool to identify important non-coding regulatory sequences as well as the discovery of novel genes relevant to lipid biology. An example of the value of this approach was the recent chance discovery of a new apolipoprotein gene (apo AV) that has dramatic effects upon triglyceride metabolism in mice and humans.

Characterization of full-length sequenced cDNA inserts (FLIcs) from Atlantic salmon (Salmo salar)

Science.gov (United States)

Andreassen, Rune; Lunner, Sigbjørn; Høyheim, Bjørn

2009-01-01

Background Sequencing of the Atlantic salmon genome is now being planned by an international research consortium. Full-length sequenced inserts from cDNAs (FLIcs) are an important tool for correct annotation and clustering of the genomic sequence in any species. The large amount of highly similar duplicate sequences caused by the relatively recent genome duplication in the salmonid ancestor represents a particular challenge for the genome project. FLIcs will therefore be an extremely useful resource for the Atlantic salmon sequencing project. In addition to be helpful in order to distinguish between duplicate genome regions and in determining correct gene structures, FLIcs are an important resource for functional genomic studies and for investigation of regulatory elements controlling gene expression. In contrast to the large number of ESTs available, including the ESTs from 23 developmental and tissue specific cDNA libraries contributed by the Salmon Genome Project (SGP), the number of sequences where the full-length of the cDNA insert has been determined has been small. Results High quality full-length insert sequences from 560 pre-smolt white muscle tissue specific cDNAs were generated, accession numbers [GenBank: BT043497 - BT044056]. Five hundred and ten (91%) of the transcripts were annotated using Gene Ontology (GO) terms and 440 of the FLIcs are likely to contain a complete coding sequence (cCDS). The sequence information was used to identify putative paralogs, characterize salmon Kozak motifs, polyadenylation signal variation and to identify motifs likely to be involved in the regulation of particular genes. Finally, conserved 7-mers in the 3'UTRs were identified, of which some were identical to miRNA target sequences. Conclusion This paper describes the first Atlantic salmon FLIcs from a tissue and developmental stage specific cDNA library. We have demonstrated that many FLIcs contained a complete coding sequence (cCDS). This suggests that the remaining c

Characterization of full-length sequenced cDNA inserts (FLIcs from Atlantic salmon (Salmo salar

Directory of Open Access Journals (Sweden)

Lunner Sigbjørn

2009-10-01

Full Text Available Abstract Background Sequencing of the Atlantic salmon genome is now being planned by an international research consortium. Full-length sequenced inserts from cDNAs (FLIcs are an important tool for correct annotation and clustering of the genomic sequence in any species. The large amount of highly similar duplicate sequences caused by the relatively recent genome duplication in the salmonid ancestor represents a particular challenge for the genome project. FLIcs will therefore be an extremely useful resource for the Atlantic salmon sequencing project. In addition to be helpful in order to distinguish between duplicate genome regions and in determining correct gene structures, FLIcs are an important resource for functional genomic studies and for investigation of regulatory elements controlling gene expression. In contrast to the large number of ESTs available, including the ESTs from 23 developmental and tissue specific cDNA libraries contributed by the Salmon Genome Project (SGP, the number of sequences where the full-length of the cDNA insert has been determined has been small. Results High quality full-length insert sequences from 560 pre-smolt white muscle tissue specific cDNAs were generated, accession numbers [GenBank: BT043497 - BT044056]. Five hundred and ten (91% of the transcripts were annotated using Gene Ontology (GO terms and 440 of the FLIcs are likely to contain a complete coding sequence (cCDS. The sequence information was used to identify putative paralogs, characterize salmon Kozak motifs, polyadenylation signal variation and to identify motifs likely to be involved in the regulation of particular genes. Finally, conserved 7-mers in the 3'UTRs were identified, of which some were identical to miRNA target sequences. Conclusion This paper describes the first Atlantic salmon FLIcs from a tissue and developmental stage specific cDNA library. We have demonstrated that many FLIcs contained a complete coding sequence (cCDS. This

Biogeographic Comparison of Lophelia-Associated Bacterial Communities in the Western Atlantic Reveals Conserved Core Microbiome

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Christina A. Kellogg

2017-05-01

Full Text Available Over the last decade, publications on deep-sea corals have tripled. Most attention has been paid to Lophelia pertusa, a globally distributed scleractinian coral that creates critical three-dimensional habitat in the deep ocean. The bacterial community associated with L. pertusa has been previously described by a number of studies at sites in the Mediterranean Sea, Norwegian fjords, off Great Britain, and in the Gulf of Mexico (GOM. However, use of different methodologies prevents direct comparisons in most cases. Our objectives were to address intra-regional variation and to identify any conserved bacterial core community. We collected samples from three distinct colonies of L. pertusa at each of four locations within the western Atlantic: three sites within the GOM and one off the east coast of the United States. Amplicon libraries of 16S rRNA genes were generated using primers targeting the V4–V5 hypervariable region and 454 pyrosequencing. The dominant phylum was Proteobacteria (75–96%. At the family level, 80–95% of each sample was comprised of five groups: Pirellulaceae, Pseudonocardiaceae, Rhodobacteraceae, Sphingomonadaceae, and unclassified Oceanospirillales. Principal coordinate analysis based on weighted UniFrac distances showed a clear distinction between the GOM and Atlantic samples. Interestingly, the replicate samples from each location did not always cluster together, indicating there is not a strong site-specific influence. The core bacterial community, conserved in 100% of the samples, was dominated by the operational taxonomic units of genera Novosphingobium and Pseudonocardia, both known degraders of aromatic hydrocarbons. The sequence of another core member, Propionibacterium, was also found in prior studies of L. pertusa from Norway and Great Britain, suggesting a role as a conserved symbiont. By examining more than 40,000 sequences per sample, we found that GOM samples were dominated by the identified conserved core

On universal common ancestry, sequence similarity, and phylogenetic structure: the sins of P-values and the virtues of Bayesian evidence

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Theobald Douglas L

2011-11-01

Full Text Available Abstract Background The universal common ancestry (UCA of all known life is a fundamental component of modern evolutionary theory, supported by a wide range of qualitative molecular evidence. Nevertheless, recently both the status and nature of UCA has been questioned. In earlier work I presented a formal, quantitative test of UCA in which model selection criteria overwhelmingly choose common ancestry over independent ancestry, based on a dataset of universally conserved proteins. These model-based tests are founded in likelihoodist and Bayesian probability theory, in opposition to classical frequentist null hypothesis tests such as Karlin-Altschul E-values for sequence similarity. In a recent comment, Koonin and Wolf (K&W claim that the model preference for UCA is "a trivial consequence of significant sequence similarity". They support this claim with a computational simulation, derived from universally conserved proteins, which produces similar sequences lacking phylogenetic structure. The model selection tests prefer common ancestry for this artificial data set. Results For the real universal protein sequences, hierarchical phylogenetic structure (induced by genealogical history is the overriding reason for why the tests choose UCA; sequence similarity is a relatively minor factor. First, for cases of conflicting phylogenetic structure, the tests choose independent ancestry even with highly similar sequences. Second, certain models, like star trees and K&W's profile model (corresponding to their simulation, readily explain sequence similarity yet lack phylogenetic structure. However, these are extremely poor models for the real proteins, even worse than independent ancestry models, though they explain K&W's artificial data well. Finally, K&W's simulation is an implementation of a well-known phylogenetic model, and it produces sequences that mimic homologous proteins. Therefore the model selection tests work appropriately with the artificial

Identification and analysis of 21 novel disease-causing amino acid substitutions in the conserved part of ATP7A

DEFF Research Database (Denmark)

Moller, L.B.; Bukrinsky, J.T.; Mølgaard, Anne

2005-01-01

ATP7A encodes a copper. translocating ATPase that belongs to the large family of P-type ATPases. Eight conserved regions define the core of the P-type ATPase superfamily. We report here the identification of 21 novel missense mutations in the conserved part of ATP7A that encodes the residues p.V842...... clustered three-dimensionally than expected from the primary sequence. The location of the substituted residues in conserved regions supports the functional similarities between the two types of P-type ATPases. An immunofluorescence analysis of Menkes fibroblasts suggested that the localization of a large...

The genome sequence of the commercially cultivated mushroom Agrocybe aegerita reveals a conserved repertoire of fruiting-related genes and a versatile suite of biopolymer-degrading enzymes.

Science.gov (United States)

Gupta, Deepak K; Rühl, Martin; Mishra, Bagdevi; Kleofas, Vanessa; Hofrichter, Martin; Herzog, Robert; Pecyna, Marek J; Sharma, Rahul; Kellner, Harald; Hennicke, Florian; Thines, Marco

2018-01-15

Agrocybe aegerita is an agaricomycete fungus with typical mushroom features, which is commercially cultivated for its culinary use. In nature, it is a saprotrophic or facultative pathogenic fungus causing a white-rot of hardwood in forests of warm and mild climate. The ease of cultivation and fructification on solidified media as well as its archetypal mushroom fruit body morphology render A. aegerita a well-suited model for investigating mushroom developmental biology. Here, the genome of the species is reported and analysed with respect to carbohydrate active genes and genes known to play a role during fruit body formation. In terms of fruit body development, our analyses revealed a conserved repertoire of fruiting-related genes, which corresponds well to the archetypal fruit body morphology of this mushroom. For some genes involved in fruit body formation, paralogisation was observed, but not all fruit body maturation-associated genes known from other agaricomycetes seem to be conserved in the genome sequence of A. aegerita. In terms of lytic enzymes, our analyses suggest a versatile arsenal of biopolymer-degrading enzymes that likely account for the flexible life style of this species. Regarding the amount of genes encoding CAZymes relevant for lignin degradation, A. aegerita shows more similarity to white-rot fungi than to litter decomposers, including 18 genes coding for unspecific peroxygenases and three dye-decolourising peroxidase genes expanding its lignocellulolytic machinery. The genome resource will be useful for developing strategies towards genetic manipulation of A. aegerita, which will subsequently allow functional genetics approaches to elucidate fundamentals of fruiting and vegetative growth including lignocellulolysis.

Sequence analysis of RNase MRP RNA reveals its origination from eukaryotic RNase P RNA

Science.gov (United States)

Zhu, Yanglong; Stribinskis, Vilius; Ramos, Kenneth S.; Li, Yong

2006-01-01

RNase MRP is a eukaryote-specific endoribonuclease that generates RNA primers for mitochondrial DNA replication and processes precursor rRNA. RNase P is a ubiquitous endoribonuclease that cleaves precursor tRNA transcripts to produce their mature 5′ termini. We found extensive sequence homology of catalytic domains and specificity domains between their RNA subunits in many organisms. In Candida glabrata, the internal loop of helix P3 is 100% conserved between MRP and P RNAs. The helix P8 of MRP RNA from microsporidia Encephalitozoon cuniculi is identical to that of P RNA. Sequence homology can be widely spread over the whole molecule of MRP RNA and P RNA, such as those from Dictyostelium discoideum. These conserved nucleotides between the MRP and P RNAs strongly support the hypothesis that the MRP RNA is derived from the P RNA molecule in early eukaryote evolution. PMID:16540690

Widespread alternative and aberrant splicing revealed by lariat sequencing

Science.gov (United States)

Stepankiw, Nicholas; Raghavan, Madhura; Fogarty, Elizabeth A.; Grimson, Andrew; Pleiss, Jeffrey A.

2015-01-01

Alternative splicing is an important and ancient feature of eukaryotic gene structure, the existence of which has likely facilitated eukaryotic proteome expansions. Here, we have used intron lariat sequencing to generate a comprehensive profile of splicing events in Schizosaccharomyces pombe, amongst the simplest organisms that possess mammalian-like splice site degeneracy. We reveal an unprecedented level of alternative splicing, including alternative splice site selection for over half of all annotated introns, hundreds of novel exon-skipping events, and thousands of novel introns. Moreover, the frequency of these events is far higher than previous estimates, with alternative splice sites on average activated at ∼3% the rate of canonical sites. Although a subset of alternative sites are conserved in related species, implying functional potential, the majority are not detectably conserved. Interestingly, the rate of aberrant splicing is inversely related to expression level, with lowly expressed genes more prone to erroneous splicing. Although we validate many events with RNAseq, the proportion of alternative splicing discovered with lariat sequencing is far greater, a difference we attribute to preferential decay of aberrantly spliced transcripts. Together, these data suggest the spliceosome possesses far lower fidelity than previously appreciated, highlighting the potential contributions of alternative splicing in generating novel gene structures. PMID:26261211

The Runt domain of AML1 (RUNX1) binds a sequence-conserved RNA motif that mimics a DNA element.

Science.gov (United States)

Fukunaga, Junichi; Nomura, Yusuke; Tanaka, Yoichiro; Amano, Ryo; Tanaka, Taku; Nakamura, Yoshikazu; Kawai, Gota; Sakamoto, Taiichi; Kozu, Tomoko

2013-07-01

AML1 (RUNX1) is a key transcription factor for hematopoiesis that binds to the Runt-binding double-stranded DNA element (RDE) of target genes through its N-terminal Runt domain. Aberrations in the AML1 gene are frequently found in human leukemia. To better understand AML1 and its potential utility for diagnosis and therapy, we obtained RNA aptamers that bind specifically to the AML1 Runt domain. Enzymatic probing and NMR analyses revealed that Apt1-S, which is a truncated variant of one of the aptamers, has a CACG tetraloop and two stem regions separated by an internal loop. All the isolated aptamers were found to contain the conserved sequence motif 5'-NNCCAC-3' and 5'-GCGMGN'N'-3' (M:A or C; N and N' form Watson-Crick base pairs). The motif contains one AC mismatch and one base bulged out. Mutational analysis of Apt1-S showed that three guanines of the motif are important for Runt binding as are the three guanines of RDE, which are directly recognized by three arginine residues of the Runt domain. Mutational analyses of the Runt domain revealed that the amino acid residues used for Apt1-S binding were similar to those used for RDE binding. Furthermore, the aptamer competed with RDE for binding to the Runt domain in vitro. These results demonstrated that the Runt domain of the AML1 protein binds to the motif of the aptamer that mimics DNA. Our findings should provide new insights into RNA function and utility in both basic and applied sciences.

DisoMCS: Accurately Predicting Protein Intrinsically Disordered Regions Using a Multi-Class Conservative Score Approach.

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Zhiheng Wang

Full Text Available The precise prediction of protein intrinsically disordered regions, which play a crucial role in biological procedures, is a necessary prerequisite to further the understanding of the principles and mechanisms of protein function. Here, we propose a novel predictor, DisoMCS, which is a more accurate predictor of protein intrinsically disordered regions. The DisoMCS bases on an original multi-class conservative score (MCS obtained by sequence-order/disorder alignment. Initially, near-disorder regions are defined on fragments located at both the terminus of an ordered region connecting a disordered region. Then the multi-class conservative score is generated by sequence alignment against a known structure database and represented as order, near-disorder and disorder conservative scores. The MCS of each amino acid has three elements: order, near-disorder and disorder profiles. Finally, the MCS is exploited as features to identify disordered regions in sequences. DisoMCS utilizes a non-redundant data set as the training set, MCS and predicted secondary structure as features, and a conditional random field as the classification algorithm. In predicted near-disorder regions a residue is determined as an order or a disorder according to the optimized decision threshold. DisoMCS was evaluated by cross-validation, large-scale prediction, independent tests and CASP (Critical Assessment of Techniques for Protein Structure Prediction tests. All results confirmed that DisoMCS was very competitive in terms of accuracy of prediction when compared with well-established publicly available disordered region predictors. It also indicated our approach was more accurate when a query has higher homologous with the knowledge database.The DisoMCS is available at http://cal.tongji.edu.cn/disorder/.

77 FR 59712 - Energy Conservation Program: Energy Conservation Standards for Dishwashers

Science.gov (United States)

2012-10-01

... amended energy conservation standards, DOE conducted a market survey using all available public... Energy Conservation Program: Energy Conservation Standards for Dishwashers AGENCY: Office of Energy... establish amended energy conservation standards for dishwashers in the Federal Register on May 30, 2012. DOE...

Superior control of HIV-1 replication by CD8+ T cells targeting conserved epitopes: implications for HIV vaccine design.

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Pratima Kunwar

Full Text Available A successful HIV vaccine will likely induce both humoral and cell-mediated immunity, however, the enormous diversity of HIV has hampered the development of a vaccine that effectively elicits both arms of the adaptive immune response. To tackle the problem of viral diversity, T cell-based vaccine approaches have focused on two main strategies (i increasing the breadth of vaccine-induced responses or (ii increasing vaccine-induced responses targeting only conserved regions of the virus. The relative extent to which set-point viremia is impacted by epitope-conservation of CD8(+ T cell responses elicited during early HIV-infection is unknown but has important implications for vaccine design. To address this question, we comprehensively mapped HIV-1 CD8(+ T cell epitope-specificities in 23 ART-naïve individuals during early infection and computed their conservation score (CS by three different methods (prevalence, entropy and conseq on clade-B and group-M sequence alignments. The majority of CD8(+ T cell responses were directed against variable epitopes (p<0.01. Interestingly, increasing breadth of CD8(+ T cell responses specifically recognizing conserved epitopes was associated with lower set-point viremia (r = - 0.65, p = 0.009. Moreover, subjects possessing CD8(+ T cells recognizing at least one conserved epitope had 1.4 log10 lower set-point viremia compared to those recognizing only variable epitopes (p = 0.021. The association between viral control and the breadth of conserved CD8(+ T cell responses may be influenced by the method of CS definition and sequences used to determine conservation levels. Strikingly, targeting variable versus conserved epitopes was independent of HLA type (p = 0.215. The associations with viral control were independent of functional avidity of CD8(+ T cell responses elicited during early infection. Taken together, these data suggest that the next-generation of T-cell based HIV-1 vaccines should focus

The conserved Tarp actin binding domain is important for chlamydial invasion.

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Travis J Jewett

2010-07-01

Full Text Available The translocated actin recruiting phosphoprotein (Tarp is conserved among all pathogenic chlamydial species. Previous reports identified single C. trachomatis Tarp actin binding and proline rich domains required for Tarp mediated actin nucleation. A peptide antiserum specific for the Tarp actin binding domain was generated and inhibited actin polymerization in vitro and C. trachomatis entry in vivo, indicating an essential role for Tarp in chlamydial pathogenesis. Sequence analysis of Tarp orthologs from additional chlamydial species and C. trachomatis serovars indicated multiple putative actin binding sites. In order to determine whether the identified actin binding domains are functionally conserved, GST-Tarp fusions from multiple chlamydial species were examined for their ability to bind and nucleate actin. Chlamydial Tarps harbored variable numbers of actin binding sites and promoted actin nucleation as determined by in vitro polymerization assays. Our findings indicate that Tarp mediated actin binding and nucleation is a conserved feature among diverse chlamydial species and this function plays a critical role in bacterial invasion of host cells.

Extended region of nodulation genes in Rhizobium meliloti 1021. II. Nucleotide sequence, transcription start sites and protein products

International Nuclear Information System (INIS)

Fisher, R.F.; Swanson, J.A.; Mulligan, J.T.; Long, S.R.

1987-01-01

The authors have established the DNA sequence and analyzed the transcription and translation products of a series of putative nodulation (nod) genes in Rhizobium meliloti strain 1021. Four loci have been designated nodF, nodE, nodG and nodH. The correlation of transposon insertion positions with phenotypes and open reading frames was confirmed by sequencing the insertion junctions of the transposons. The protein products of these nod genes were visualized by in vitro expression of cloned DNA segments in a R. meliloti transcription-translation system. In addition, the sequence for nodG was substantiated by creating translational fusions in all three reading frames at several points in the sequence; the resulting fusions were expressed in vitro in both E. coli and R. meliloti transcription-translation systems. A DNA segment bearing several open reading frames downstream of nodG corresponds to the putative nod gene mutated in strain nod-216. The transcription start sites of nodF and nodH were mapped by primer extension of RNA from cells induced with the plant flavone, luteolin. Initiation of transcription occurs approximately 25 bp downstream from the conserved sequence designated the nod box, suggesting that this conserved sequence acts as an upstream regulator of inducible nod gene expression. Its distance from the transcription start site is more suggestive of an activator binding site rather than an RNA polymerase binding site

Allele frequencies of variants in ultra conserved elements identify selective pressure on transcription factor binding.

Science.gov (United States)

Silla, Toomas; Kepp, Katrin; Tai, E Shyong; Goh, Liang; Davila, Sonia; Catela Ivkovic, Tina; Calin, George A; Voorhoeve, P Mathijs

2014-01-01

Ultra-conserved genes or elements (UCGs/UCEs) in the human genome are extreme examples of conservation. We characterized natural variations in 2884 UCEs and UCGs in two distinct populations; Singaporean Chinese (n = 280) and Italian (n = 501) by using a pooled sample, targeted capture, sequencing approach. We identify, with high confidence, in these regions the abundance of rare SNVs (MAFpower for association studies. By combining our data with 1000 Genome Project data, we show in three independent datasets that prevalent UCE variants (MAF>5%) are more often found in relatively less-conserved nucleotides within UCEs, compared to rare variants. Moreover, prevalent variants are less likely to overlap transcription factor binding site. Using SNPfold we found no significant influence of RNA secondary structure on UCE conservation. All together, these results suggest UCEs are not under selective pressure as a stretch of DNA but are under differential evolutionary pressure on the single nucleotide level.

Monomorphism in humans and sequence differences among higher primates for a sequence tagged site (STS) in homeo box cluster 2 as assayed by denaturing gradient electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Ruano, G.; Ruddle, F.H.; Kidd, K.K. (Yale Univ., New Haven, CT (United States)); Gray, M.R. (Tufts Univ., Boston, MA (United States)); Miki, Tetsuro (Osaka Univ. (Japan)); Ferguson-Smith, A.C. (Inst. of Animal Physiology and Genetics Research, Cambridge (United Kingdom))

1990-03-11

The human homeo box cluster 2 (HOX2) contains genes coding for DNA binding proteins involved in developmental control and is highly conserved between mouse and man. The authors have applied in concert the Polymerase Chain Reaction (PCR) and Denaturing Gradient Electrophoresis (DGE) to amplify defined primate HOX2 segments and to detect sequence differences among them. They have sequenced a PstI fragment 4 kb upstream from HOX 2.2 and synthesized primers delimiting both halves of 630 bp segment within it PCR on various unrelated humans and SC-PCR on chimpanzee, gorilla, orangutan and gibbon yielded products of the same length for each primer pair.

Novel Approach to Analyzing MFE of Noncoding RNA Sequences.

Science.gov (United States)

George, Tina P; Thomas, Tessamma

2016-01-01

Genomic studies have become noncoding RNA (ncRNA) centric after the study of different genomes provided enormous information on ncRNA over the past decades. The function of ncRNA is decided by its secondary structure, and across organisms, the secondary structure is more conserved than the sequence itself. In this study, the optimal secondary structure or the minimum free energy (MFE) structure of ncRNA was found based on the thermodynamic nearest neighbor model. MFE of over 2600 ncRNA sequences was analyzed in view of its signal properties. Mathematical models linking MFE to the signal properties were found for each of the four classes of ncRNA analyzed. MFE values computed with the proposed models were in concordance with those obtained with the standard web servers. A total of 95% of the sequences analyzed had deviation of MFE values within ±15% relative to those obtained from standard web servers.

The identification and functional annotation of RNA structures conserved in vertebrates

DEFF Research Database (Denmark)

Seemann, Ernst Stefan; Mirza, Aashiq Hussain; Hansen, Claus

2017-01-01

Structured elements of RNA molecules are essential in, e.g., RNA stabilization, localization and protein interaction, and their conservation across species suggests a common functional role. We computationally screened vertebrate genomes for Conserved RNA Structures (CRSs), leveraging structure...... (RBPs) or (ii) are transcribed in corresponding tissues. Additionally, a CaptureSeq experiment revealed expression of many of our CRS regions in human fetal brain, including 662 novel ones. For selected human and mouse candidate pairs, qRT-PCR and in vitro RNA structure probing supported both shared...... expression and shared structure despite low abundance and low sequence identity. About 30k CRS regions are located near coding or long non-coding RNA genes or within enhancers. Structured (CRS overlapping) enhancer RNAs and extended 3' ends have significantly increased expression levels over their non-structured...

Use of genotyping by sequencing data to develop a high-throughput and multifunctional SNP panel for conservation applications in Pacific lamprey.

Science.gov (United States)

Hess, Jon E; Campbell, Nathan R; Docker, Margaret F; Baker, Cyndi; Jackson, Aaron; Lampman, Ralph; McIlraith, Brian; Moser, Mary L; Statler, David P; Young, William P; Wildbill, Andrew J; Narum, Shawn R

2015-01-01

Next-generation sequencing data can be mined for highly informative single nucleotide polymorphisms (SNPs) to develop high-throughput genomic assays for nonmodel organisms. However, choosing a set of SNPs to address a variety of objectives can be difficult because SNPs are often not equally informative. We developed an optimal combination of 96 high-throughput SNP assays from a total of 4439 SNPs identified in a previous study of Pacific lamprey (Entosphenus tridentatus) and used them to address four disparate objectives: parentage analysis, species identification and characterization of neutral and adaptive variation. Nine of these SNPs are FST outliers, and five of these outliers are localized within genes and significantly associated with geography, run-timing and dwarf life history. Two of the 96 SNPs were diagnostic for two other lamprey species that were morphologically indistinguishable at early larval stages and were sympatric in the Pacific Northwest. The majority (85) of SNPs in the panel were highly informative for parentage analysis, that is, putatively neutral with high minor allele frequency across the species' range. Results from three case studies are presented to demonstrate the broad utility of this panel of SNP markers in this species. As Pacific lamprey populations are undergoing rapid decline, these SNPs provide an important resource to address critical uncertainties associated with the conservation and recovery of this imperiled species. © 2014 John Wiley & Sons Ltd.

Investigation of bacterial communities in peat land of the Gahai Lake natural conservation area

Science.gov (United States)

Bai, Yani; Wang, Jinchang; Zhan, Zhigao; Guan, Limei; Jin, Liang; Zheng, Guohua

2017-10-01

Peat is involved in the global carbon cycle and water conservation; therefore, it is implicated in global environmental change. Microorganisms play an important role in the function of peat. To investigate the bacterial communities in peat of Gahai Lake, different locations and depths were sampled and Illumina Miseq sequencing was used to analyze the microbial community. Chemical properties of peat samples were analyzed by China state standard methods (GB methods). The results showed that bacterial communities were affected by depth, with bacterial diversity and community structure at 90 and 120 cm significantly different from that at 10, 30 and 50 cm depth from the peat surface. Chemical properties of peat land including organic matter, total nitrogen and humus content did not significantly influence bacterial community structure in peat, with only one group from genus Rhizomicrobium that was significantly correlated with total nitrogen. A substantial proportion of the bacterial sequences were unclassified (1.4%), which indicates the great application potential of peat in the Gahai Lake natural conservation area in the future.

Exploiting CRISPR-Cas nucleases to produce sequence-specific antimicrobials.

Science.gov (United States)

Bikard, David; Euler, Chad W; Jiang, Wenyan; Nussenzweig, Philip M; Goldberg, Gregory W; Duportet, Xavier; Fischetti, Vincent A; Marraffini, Luciano A

2014-11-01

Antibiotics target conserved bacterial cellular pathways or growth functions and therefore cannot selectively kill specific members of a complex microbial population. Here, we develop programmable, sequence-specific antimicrobials using the RNA-guided nuclease Cas9 (refs.1,2) delivered by a bacteriophage. We show that Cas9, reprogrammed to target virulence genes, kills virulent, but not avirulent, Staphylococcus aureus. Reprogramming the nuclease to target antibiotic resistance genes destroys staphylococcal plasmids that harbor antibiotic resistance genes and immunizes avirulent staphylococci to prevent the spread of plasmid-borne resistance genes. We also show that CRISPR-Cas9 antimicrobials function in vivo to kill S. aureus in a mouse skin colonization model. This technology creates opportunities to manipulate complex bacterial populations in a sequence-specific manner.

A study on hydrogen deflagration for selected severe accident sequences in Ringhals 3

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, V.; Moeller, E. [SwedPower AB (Sweden)

2002-01-01

In this report, we have investigated the most important severe accident sequences in Ringhals 3, a Westinghouse 3-loop PWR, concerning hydrogen generation and containment pressure at hydrogen deflagration. In order to analyze the accident sequences and to calculate the hydrogen production, the computer code MAAP (Modular Accident Analysis Program) was used. Six accident sequences were studied, where four were LOCA cases and two transients. MAAP gives the evolution of the accident and particularly the pressure in the containment and the production of hydrogen as a function of time. The pressure peaks at deflagration were calculated by the method AICC-Adiabatic Isochoric Complete Combustion. The results from these calculations are conservative for two reasons. Adiabatic combustion means that the heat losses to structures in the containment are neglected. The combustion is also assumed to occur once and all available hydrogen is burned. The maximum pressure in five analysed cases was compared with the failure pressure of the containment. In the LOCA case, 373 kg hydrogen was burned and the resulting peak pressure in the containment was 0,53 MPa. In the transient, where 720 kg hydrogen was burned, the peak pressure was 0,69 MPa. This is the same as the failure pressure of the containment. Finally, in the conservative case, 980 kg hydrogen was burned and the resulting peak pressure 0,96 MPa. However, it should be noted that these conclusions are conservative from two points of view. Firstly a more realistic (than AICC) calculation of the peak pressure would give a lower value than 0,69 MPa. Secondly, there is conservatism in the evaluation of the failure pressure. (au)

A functional analysis of the spacer of V(D)J recombination signal sequences.

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Lee, Alfred Ian; Fugmann, Sebastian D; Cowell, Lindsay G; Ptaszek, Leon M; Kelsoe, Garnett; Schatz, David G

2003-10-01

During lymphocyte development, V(D)J recombination assembles antigen receptor genes from component V, D, and J gene segments. These gene segments are flanked by a recombination signal sequence (RSS), which serves as the binding site for the recombination machinery. The murine Jbeta2.6 gene segment is a recombinationally inactive pseudogene, but examination of its RSS reveals no obvious reason for its failure to recombine. Mutagenesis of the Jbeta2.6 RSS demonstrates that the sequences of the heptamer, nonamer, and spacer are all important. Strikingly, changes solely in the spacer sequence can result in dramatic differences in the level of recombination. The subsequent analysis of a library of more than 4,000 spacer variants revealed that spacer residues of particular functional importance are correlated with their degree of conservation. Biochemical assays indicate distinct cooperation between the spacer and heptamer/nonamer along each step of the reaction pathway. The results suggest that the spacer serves not only to ensure the appropriate distance between the heptamer and nonamer but also regulates RSS activity by providing additional RAG:RSS interaction surfaces. We conclude that while RSSs are defined by a "digital" requirement for absolutely conserved nucleotides, the quality of RSS function is determined in an "analog" manner by numerous complex interactions between the RAG proteins and the less-well conserved nucleotides in the heptamer, the nonamer, and, importantly, the spacer. Those modulatory effects are accurately predicted by a new computational algorithm for "RSS information content." The interplay between such binary and multiplicative modes of interactions provides a general model for analyzing protein-DNA interactions in various biological systems.

Cloning and sequence analysis of a partial CDS of leptospiral ligA gene in pET-32a - Escherichia coli DH5α system

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Manju Soman

2018-04-01

Full Text Available Aim: This study aims at cloning, sequencing, and phylogenetic analysis of a partial CDS of ligA gene in pET-32a - Escherichia coli DH5α system, with the objective of identifying the conserved nature of the ligA gene in the genus Leptospira. Materials and Methods: A partial CDS (nucleotide 1873 to nucleotide 3363 of the ligA gene was amplified from genomic DNA of Leptospira interrogans serovar Canicola by polymerase chain reaction (PCR. The PCR-amplified DNA was cloned into pET-32a vector and transformed into competent E. coli DH5α bacterial cells. The partial ligA gene insert was sequenced and the nucleotide sequences obtained were aligned with the published ligA gene sequences of other Leptospira serovars, using nucleotide BLAST, NCBI. Phylogenetic analysis of the gene sequence was done by maximum likelihood method using Mega 6.06 software. Results: The PCR could amplify the 1491 nucleotide sequence spanning from nucleotide 1873 to nucleotide 3363 of the ligA gene and the partial ligA gene could be successfully cloned in E. coli DH5α cells. The nucleotide sequence when analyzed for homology with the reported gene sequences of other Leptospira serovars was found to have 100% homology to the 1910 bp to 3320 bp sequence of ligA gene of L. interrogans strain Kito serogroup Canicola. The predicted protein consisted of 470 aminoacids. Phylogenetic analysis revealed that the ligA gene was conserved in L. interrogans species. Conclusion: The partial ligA gene could be successfully cloned and sequenced from E. coli DH5α cells. The sequence showed 100% homology to the published ligA gene sequences. The phylogenetic analysis revealed the conserved nature of the ligA gene. Further studies on the expression and immunogenicity of the partial LigA protein need to be carried out to determine its competence as a subunit vaccine candidate.

MicroRNA repertoire for functional genome research in tilapia identified by deep sequencing.

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Yan, Biao; Wang, Zhen-Hua; Zhu, Chang-Dong; Guo, Jin-Tao; Zhao, Jin-Liang

2014-08-01

The Nile tilapia (Oreochromis niloticus; Cichlidae) is an economically important species in aquaculture and occupies a prominent position in the aquaculture industry. MicroRNAs (miRNAs) are a class of noncoding RNAs that post-transcriptionally regulate gene expression involved in diverse biological and metabolic processes. To increase the repertoire of miRNAs characterized in tilapia, we used the Illumina/Solexa sequencing technology to sequence a small RNA library using pooled RNA sample isolated from the different developmental stages of tilapia. Bioinformatic analyses suggest that 197 conserved and 27 novel miRNAs are expressed in tilapia. Sequence alignments indicate that all tested miRNAs and miRNAs* are highly conserved across many species. In addition, we characterized the tissue expression patterns of five miRNAs using real-time quantitative PCR. We found that miR-1/206, miR-7/9, and miR-122 is abundantly expressed in muscle, brain, and liver, respectively, implying a potential role in the regulation of tissue differentiation or the maintenance of tissue identity. Overall, our results expand the number of tilapia miRNAs, and the discovery of miRNAs in tilapia genome contributes to a better understanding the role of miRNAs in regulating diverse biological processes.

Comparative sequence analysis of Sordaria macrospora and Neurospora crassa as a means to improve genome annotation.

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Nowrousian, Minou; Würtz, Christian; Pöggeler, Stefanie; Kück, Ulrich

2004-03-01

One of the most challenging parts of large scale sequencing projects is the identification of functional elements encoded in a genome. Recently, studies of genomes of up to six different Saccharomyces species have demonstrated that a comparative analysis of genome sequences from closely related species is a powerful approach to identify open reading frames and other functional regions within genomes [Science 301 (2003) 71, Nature 423 (2003) 241]. Here, we present a comparison of selected sequences from Sordaria macrospora to their corresponding Neurospora crassa orthologous regions. Our analysis indicates that due to the high degree of sequence similarity and conservation of overall genomic organization, S. macrospora sequence information can be used to simplify the annotation of the N. crassa genome.

Conservation and diversity of influenza A H1N1 HLA-restricted T cell epitope candidates for epitope-based vaccines.

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Paul Thiamjoo Tan

2010-01-01

Full Text Available The immune-related evolution of influenza viruses is exceedingly complex and current vaccines against influenza must be reformulated for each influenza season because of the high degree of antigenic drift among circulating influenza strains. Delay in vaccine production is a serious problem in responding to a pandemic situation, such as that of the current H1N1 strain. Immune escape is generally attributed to reduced antibody recognition of the viral hemagglutinin and neuraminidase proteins whose rate of mutation is much greater than that of the internal non-structural proteins. As a possible alternative, vaccines directed at T cell epitope domains of internal influenza proteins, that are less susceptible to antigenic variation, have been investigated.HLA transgenic mouse strains expressing HLA class I A*0201, A*2402, and B*0702, and class II DRB1*1501, DRB1*0301 and DRB1*0401 were immunized with 196 influenza H1N1 peptides that contained residues of highly conserved proteome sequences of the human H1N1, H3N2, H1N2, H5N1, and avian influenza A strains. Fifty-four (54 peptides that elicited 63 HLA-restricted peptide-specific T cell epitope responses were identified by IFN-gamma ELISpot assay. The 54 peptides were compared to the 2007-2009 human H1N1 sequences for selection of sequences in the design of a new candidate H1N1 vaccine, specifically targeted to highly-conserved HLA-restricted T cell epitopes.Seventeen (17 T cell epitopes in PB1, PB2, and M1 were selected as vaccine targets based on sequence conservation over the past 30 years, high functional avidity, non-identity to human peptides, clustered localization, and promiscuity to multiple HLA alleles. These candidate vaccine antigen sequences may be applicable to any avian or human influenza A virus.

Genomic Imprinting Was Evolutionarily Conserved during Wheat Polyploidization.

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Yang, Guanghui; Liu, Zhenshan; Gao, Lulu; Yu, Kuohai; Feng, Man; Yao, Yingyin; Peng, Huiru; Hu, Zhaorong; Sun, Qixin; Ni, Zhongfu; Xin, Mingming

2018-01-01

Genomic imprinting is an epigenetic phenomenon that causes genes to be differentially expressed depending on their parent of origin. To evaluate the evolutionary conservation of genomic imprinting and the effects of ploidy on this process, we investigated parent-of-origin-specific gene expression patterns in the endosperm of diploid ( Aegilops spp), tetraploid, and hexaploid wheat ( Triticum spp) at various stages of development via high-throughput transcriptome sequencing. We identified 91, 135, and 146 maternally or paternally expressed genes (MEGs or PEGs, respectively) in diploid, tetraploid, and hexaploid wheat, respectively, 52.7% of which exhibited dynamic expression patterns at different developmental stages. Gene Ontology enrichment analysis suggested that MEGs and PEGs were involved in metabolic processes and DNA-dependent transcription, respectively. Nearly half of the imprinted genes exhibited conserved expression patterns during wheat hexaploidization. In addition, 40% of the homoeolog pairs originating from whole-genome duplication were consistently maternally or paternally biased in the different subgenomes of hexaploid wheat. Furthermore, imprinted expression was found for 41.2% and 50.0% of homolog pairs that evolved by tandem duplication after genome duplication in tetraploid and hexaploid wheat, respectively. These results suggest that genomic imprinting was evolutionarily conserved between closely related Triticum and Aegilops species and in the face of polyploid hybridization between species in these genera. © 2018 American Society of Plant Biologists. All rights reserved.

Stereophysicochemical variability plots highlight conserved antigenic areas in Flaviviruses

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Zhou Bin

2005-04-01

Full Text Available Abstract Background Flaviviruses, which include Dengue (DV and West Nile (WN, mutate in response to immune system pressure. Identifying escape mutants, variant progeny that replicate in the presence of neutralizing antibodies, is a common way to identify functionally important residues of viral proteins. However, the mutations typically occur at variable positions on the viral surface that are not essential for viral replication. Methods are needed to determine the true targets of the neutralizing antibodies. Results Stereophysicochemical variability plots (SVPs, 3-D images of protein structures colored according to variability, as determined by our PCPMer program, were used to visualize residues conserved in their physical chemical properties (PCPs near escape mutant positions. The analysis showed 1 that escape mutations in the flavivirus envelope protein are variable residues by our criteria and 2 two escape mutants found at the same position in many flaviviruses sit above clusters of conserved residues from different regions of the linear sequence. Conservation patterns in T-cell epitopes in the NS3- protease suggest a similar mechanism of immune system evasion. Conclusion The SVPs add another dimension to structurally defining the binding sites of neutralizing antibodies. They provide a useful aid for determining antigenically important regions and designing vaccines.

The Complete Chloroplast Genome Sequences of the Medicinal Plant Forsythia suspensa (Oleaceae

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Wenbin Wang

2017-10-01

Full Text Available Forsythia suspensa is an important medicinal plant and traditionally applied for the treatment of inflammation, pyrexia, gonorrhea, diabetes, and so on. However, there is limited sequence and genomic information available for F. suspensa. Here, we produced the complete chloroplast genomes of F. suspensa using Illumina sequencing technology. F. suspensa is the first sequenced member within the genus Forsythia (Oleaceae. The gene order and organization of the chloroplast genome of F. suspensa are similar to other Oleaceae chloroplast genomes. The F. suspensa chloroplast genome is 156,404 bp in length, exhibits a conserved quadripartite structure with a large single-copy (LSC; 87,159 bp region, and a small single-copy (SSC; 17,811 bp region interspersed between inverted repeat (IRa/b; 25,717 bp regions. A total of 114 unique genes were annotated, including 80 protein-coding genes, 30 tRNA, and four rRNA. The low GC content (37.8% and codon usage bias for A- or T-ending codons may largely affect gene codon usage. Sequence analysis identified a total of 26 forward repeats, 23 palindrome repeats with lengths >30 bp (identity > 90%, and 54 simple sequence repeats (SSRs with an average rate of 0.35 SSRs/kb. We predicted 52 RNA editing sites in the chloroplast of F. suspensa, all for C-to-U transitions. IR expansion or contraction and the divergent regions were analyzed among several species including the reported F. suspensa in this study. Phylogenetic analysis based on whole-plastome revealed that F. suspensa, as a member of the Oleaceae family, diverged relatively early from Lamiales. This study will contribute to strengthening medicinal resource conservation, molecular phylogenetic, and genetic engineering research investigations of this species.

Conservation

NARCIS (Netherlands)

Noteboom, H.P.

1985-01-01

The IUCN/WWF Plants Conservation Programme 1984 — 1985. World Wildlife Fund chose plants to be the subject of their fund-raising campaign in the period 1984 — 1985. The objectives were to: 1. Use information techniques to achieve the conservation objectives of the Plants Programme – to save plants;

Ballooning mode second stability region for sequences of tokamak equilibria

International Nuclear Information System (INIS)

Sugiyama, L.; Mark, J.W.K.

A numerical study of several sequences of tokamak equilibria derived from two flux conserving sequences confirms the tendency of high n ideal MHD ballooning modes to stabilize for values of the plasma beta greater than a second critical beta, for sufficiently favorable equilibria. The major stabilizing effect of increasing the inverse rotational transform profile q(Psi) for equilibria with the same flux surface geometry is shown. The unstable region shifts toward larger shear d ln q/d ln γ and the width of the region measured in terms of the poloidal beta or a pressure gradient parameter, for fixed shear, decreases. The smaller aspect ratio sequences are more sensitive to changes in q and have less stringent limits on the attainable value of the plasma beta in the high beta stable region. Finally, the disconnected mode approximation is shown to provide a reasonable description of the second high beta stability boundary

The genome sequence of a widespread apex Predator, the golden eagle (Aquila chrysaetos)

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Jacqueline M. Doyle; Todd E. Katzner; Peter H. Bloom; Yanzhu Ji; Bhagya K. Wijayawardena; J. Andrew DeWoody; Ludovic. Orlando

2014-01-01

Biologists routinely use molecular markers to identify conservation units, to quantify genetic connectivity, to estimate population sizes, and to identify targets of selection. Many imperiled eagle populations require such efforts and would benefit from enhanced genomic resources. We sequenced, assembled, and annotated the first eagle genome using DNA from a male...

Characterization of novel precursor miRNAs using next generation sequencing and prediction of miRNA targets in Atlantic halibut.

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Teshome Tilahun Bizuayehu

Full Text Available BACKGROUND: microRNAs (miRNAs are implicated in regulation of many cellular processes. miRNAs are processed to their mature functional form in a step-wise manner by multiple proteins and cofactors in the nucleus and cytoplasm. Many miRNAs are conserved across vertebrates. Mature miRNAs have recently been characterized in Atlantic halibut (Hippoglossus hippoglossus L.. The aim of this study was to identify and characterize precursor miRNA (pre-miRNAs and miRNA targets in this non-model flatfish. Discovery of miRNA precursor forms and targets in non-model organisms is difficult because of limited source information available. Therefore, we have developed a methodology to overcome this limitation. METHODS: Genomic DNA and small transcriptome of Atlantic halibut were sequenced using Roche 454 pyrosequencing and SOLiD next generation sequencing (NGS, respectively. Identified pre- miRNAs were further validated with reverse-transcription PCR. miRNA targets were identified using miRanda and RNAhybrid target prediction tools using sequences from public databases. Some of miRNA targets were also identified using RACE-PCR. miRNA binding sites were validated with luciferase assay using the RTS34st cell line. RESULTS: We obtained more than 1.3 M and 92 M sequence reads from 454 genomic DNA sequencing and SOLiD small RNA sequencing, respectively. We identified 34 known and 9 novel pre-miRNAs. We predicted a number of miRNA target genes involved in various biological pathways. miR-24 binding to kisspeptin 1 receptor-2 (kiss1-r2 was confirmed using luciferase assay. CONCLUSION: This study demonstrates that identification of conserved and novel pre-miRNAs in a non-model vertebrate lacking substantial genomic resources can be performed by combining different next generation sequencing technologies. Our results indicate a wide conservation of miRNA precursors and involvement of miRNA in multiple regulatory pathways, and provide resources for further research on mi

Identification and Characterization of Wilt and Salt Stress-Responsive MicroRNAs in Chickpea through High-Throughput Sequencing

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Deokar, Amit Atmaram; Bhardwaj, Ankur R.; Agarwal, Manu; Katiyar-Agarwal, Surekha; Srinivasan, Ramamurthy; Jain, Pradeep Kumar

2014-01-01

Chickpea (Cicer arietinum) is the second most widely grown legume worldwide and is the most important pulse crop in the Indian subcontinent. Chickpea productivity is adversely affected by a large number of biotic and abiotic stresses. MicroRNAs (miRNAs) have been implicated in the regulation of plant responses to several biotic and abiotic stresses. This study is the first attempt to identify chickpea miRNAs that are associated with biotic and abiotic stresses. The wilt infection that is caused by the fungus Fusarium oxysporum f.sp. ciceris is one of the major diseases severely affecting chickpea yields. Of late, increasing soil salinization has become a major problem in realizing these potential yields. Three chickpea libraries using fungal-infected, salt-treated and untreated seedlings were constructed and sequenced using next-generation sequencing technology. A total of 12,135,571 unique reads were obtained. In addition to 122 conserved miRNAs belonging to 25 different families, 59 novel miRNAs along with their star sequences were identified. Four legume-specific miRNAs, including miR5213, miR5232, miR2111 and miR2118, were found in all of the libraries. Poly(A)-based qRT-PCR (Quantitative real-time PCR) was used to validate eleven conserved and five novel miRNAs. miR530 was highly up regulated in response to fungal infection, which targets genes encoding zinc knuckle- and microtubule-associated proteins. Many miRNAs responded in a similar fashion under both biotic and abiotic stresses, indicating the existence of cross talk between the pathways that are involved in regulating these stresses. The potential target genes for the conserved and novel miRNAs were predicted based on sequence homologies. miR166 targets a HD-ZIPIII transcription factor and was validated by 5′ RLM-RACE. This study has identified several conserved and novel miRNAs in the chickpea that are associated with gene regulation following exposure to wilt and salt stress. PMID:25295754

Conservation.

Science.gov (United States)

National Audubon Society, New York, NY.

This set of teaching aids consists of seven Audubon Nature Bulletins, providing the teacher and student with informational reading on various topics in conservation. The bulletins have these titles: Plants as Makers of Soil, Water Pollution Control, The Ground Water Table, Conservation--To Keep This Earth Habitable, Our Threatened Air Supply,…

Conservation Triage Falls Short Because Conservation Is Not Like Emergency Medicine

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John A. Vucetich

2017-05-01

Full Text Available Conservation triage, as a concept, seems to have been born from analogizing circumstances that characterize conservation with triage, as the concept applies to emergency medicine. Careful consideration—facilitated through the aid of formal argumentation—demonstrates the critical limitations of the analogy. Those limitations reveal how the concept of conservation triage falls short. For example, medical triage presupposes that resources available for an emergency are limited and fixed. By contrast, the resources available for conservation are not fixed. Moreover, the ethics of prioritization in medical triage is characterized by there being universal agreement on the moral value of the patients. However, in conservation there is not universal agreement on the value of various objects of conservation concern. The looming importance of those features of conservation—disputed values and unfixed resources—make conservation triage a largely un-useful concept.

Requirement of Sequences outside the Conserved Kinase Domain of Fission Yeast Rad3p for Checkpoint Control

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Chapman, Carolyn Riley; Evans, Sarah Tyler; Carr, Antony M.; Enoch, Tamar

1999-01-01

The fission yeast Rad3p checkpoint protein is a member of the phosphatidylinositol 3-kinase-related family of protein kinases, which includes human ATMp. Mutation of the ATM gene is responsible for the disease ataxia-telangiectasia. The kinase domain of Rad3p has previously been shown to be essential for function. Here, we show that although this domain is necessary, it is not sufficient, because the isolated kinase domain does not have kinase activity in vitro and cannot complement a rad3 deletion strain. Using dominant negative alleles of rad3, we have identified two sites N-terminal to the conserved kinase domain that are essential for Rad3p function. One of these sites is the putative leucine zipper, which is conserved in other phosphatidylinositol 3-kinase-related family members. The other is a novel motif, which may also mediate Rad3p protein–protein interactions. PMID:10512862

Telomeric expression sites are highly conserved in Trypanosoma brucei.

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Christiane Hertz-Fowler

Full Text Available Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs. The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology.

Characterization of promoter sequence of toll-like receptor genes in Vechur cattle

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R. Lakshmi

2016-06-01

Full Text Available Aim: To analyze the promoter sequence of toll-like receptor (TLR genes in Vechur cattle, an indigenous breed of Kerala with the sequence of Bos taurus and access the differences that could be attributed to innate immune responses against bovine mastitis. Materials and Methods: Blood samples were collected from Jugular vein of Vechur cattle, maintained at Vechur cattle conservation center of Kerala Veterinary and Animal Sciences University, using an acid-citrate-dextrose anticoagulant. The genomic DNA was extracted, and polymerase chain reaction was carried out to amplify the promoter region of TLRs. The amplified product of TLR2, 4, and 9 promoter regions was sequenced by Sanger enzymatic DNA sequencing technique. Results: The sequence of promoter region of TLR2 of Vechur cattle with the B. taurus sequence present in GenBank showed 98% similarity and revealed variants for four sequence motifs. The sequence of the promoter region of TLR4 of Vechur cattle revealed 99% similarity with that of B. taurus sequence but not reveals significant variant in motifregions. However, two heterozygous loci were observed from the chromatogram. Promoter sequence of TLR9 gene also showed 99% similarity to B. taurus sequence and revealed variants for four sequence motifs. Conclusion: The results of this study indicate that significant variation in the promoter of TLR2 and 9 genes in Vechur cattle breed and may potentially link the influence the innate immunity response against mastitis diseases.

FragKB: structural and literature annotation resource of conserved peptide fragments and residues.

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Ashish V Tendulkar

Full Text Available BACKGROUND: FragKB (Fragment Knowledgebase is a repository of clusters of structurally similar fragments from proteins. Fragments are annotated with information at the level of sequence, structure and function, integrating biological descriptions derived from multiple existing resources and text mining. METHODOLOGY: FragKB contains approximately 400,000 conserved fragments from 4,800 representative proteins from PDB. Literature annotations are extracted from more than 1,700 articles and are available for over 12,000 fragments. The underlying systematic annotation workflow of FragKB ensures efficient update and maintenance of this database. The information in FragKB can be accessed through a web interface that facilitates sequence and structural visualization of fragments together with known literature information on the consequences of specific residue mutations and functional annotations of proteins and fragment clusters. FragKB is accessible online at http://ubio.bioinfo.cnio.es/biotools/fragkb/. SIGNIFICANCE: The information presented in FragKB can be used for modeling protein structures, for designing novel proteins and for functional characterization of related fragments. The current release is focused on functional characterization of proteins through inspection of conservation of the fragments.

Pigs in sequence space: A 0.66X coverage pig genome survey based on shotgun sequencing

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Li Wei

2005-05-01

Full Text Available Abstract Background Comparative whole genome analysis of Mammalia can benefit from the addition of more species. The pig is an obvious choice due to its economic and medical importance as well as its evolutionary position in the artiodactyls. Results We have generated ~3.84 million shotgun sequences (0.66X coverage from the pig genome. The data are hereby released (NCBI Trace repository with center name "SDJVP", and project name "Sino-Danish Pig Genome Project" together with an initial evolutionary analysis. The non-repetitive fraction of the sequences was aligned to the UCSC human-mouse alignment and the resulting three-species alignments were annotated using the human genome annotation. Ultra-conserved elements and miRNAs were identified. The results show that for each of these types of orthologous data, pig is much closer to human than mouse is. Purifying selection has been more efficient in pig compared to human, but not as efficient as in mouse, and pig seems to have an isochore structure most similar to the structure in human. Conclusion The addition of the pig to the set of species sequenced at low coverage adds to the understanding of selective pressures that have acted on the human genome by bisecting the evolutionary branch between human and mouse with the mouse branch being approximately 3 times as long as the human branch. Additionally, the joint alignment of the shot-gun sequences to the human-mouse alignment offers the investigator a rapid way to defining specific regions for analysis and resequencing.

Conservation genomics of natural and managed populations: building a conceptual and practical framework.

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Benestan, Laura Marilyn; Ferchaud, Anne-Laure; Hohenlohe, Paul A; Garner, Brittany A; Naylor, Gavin J P; Baums, Iliana Brigitta; Schwartz, Michael K; Kelley, Joanna L; Luikart, Gordon

2016-07-01

The boom of massive parallel sequencing (MPS) technology and its applications in conservation of natural and managed populations brings new opportunities and challenges to meet the scientific questions that can be addressed. Genomic conservation offers a wide range of approaches and analytical techniques, with their respective strengths and weaknesses that rely on several implicit assumptions. However, finding the most suitable approaches and analysis regarding our scientific question are often difficult and time-consuming. To address this gap, a recent workshop entitled 'ConGen 2015' was held at Montana University in order to bring together the knowledge accumulated in this field and to provide training in conceptual and practical aspects of data analysis applied to the field of conservation and evolutionary genomics. Here, we summarize the expertise yield by each instructor that has led us to consider the importance of keeping in mind the scientific question from sampling to management practices along with the selection of appropriate genomics tools and bioinformatics challenges. © 2016 John Wiley & Sons Ltd.

Identification and Characterization of MicroRNAs in Small Brown Planthopper (Laodephax striatellus) by Next-Generation Sequencing

Science.gov (United States)

Lou, Yonggen; Cheng, Jia'an; Zhang, Hengmu; Xu, Jian-Hong

2014-01-01

MicroRNAs (miRNAs) are endogenous non-coding small RNAs that regulate gene expression at the post-transcriptional level and are thought to play critical roles in many metabolic activities in eukaryotes. The small brown planthopper (Laodephax striatellus Fallén), one of the most destructive agricultural pests, causes great damage to crops including rice, wheat, and maize. However, information about the genome of L. striatellus is limited. In this study, a small RNA library was constructed from a mixed L. striatellus population and sequenced by Solexa sequencing technology. A total of 501 mature miRNAs were identified, including 227 conserved and 274 novel miRNAs belonging to 125 and 250 families, respectively. Sixty-nine conserved miRNAs that are included in 38 families are predicted to have an RNA secondary structure typically found in miRNAs. Many miRNAs were validated by stem-loop RT-PCR. Comparison with the miRNAs in 84 animal species from miRBase showed that the conserved miRNA families we identified are highly conserved in the Arthropoda phylum. Furthermore, miRanda predicted 2701 target genes for 378 miRNAs, which could be categorized into 52 functional groups annotated by gene ontology. The function of miRNA target genes was found to be very similar between conserved and novel miRNAs. This study of miRNAs in L. striatellus will provide new information and enhance the understanding of the role of miRNAs in the regulation of L. striatellus metabolism and development. PMID:25057821

Identification and characterization of microRNAs in small brown planthopper (Laodephax striatellus by next-generation sequencing.

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Guoyan Zhou

Full Text Available MicroRNAs (miRNAs are endogenous non-coding small RNAs that regulate gene expression at the post-transcriptional level and are thought to play critical roles in many metabolic activities in eukaryotes. The small brown planthopper (Laodephax striatellus Fallén, one of the most destructive agricultural pests, causes great damage to crops including rice, wheat, and maize. However, information about the genome of L. striatellus is limited. In this study, a small RNA library was constructed from a mixed L. striatellus population and sequenced by Solexa sequencing technology. A total of 501 mature miRNAs were identified, including 227 conserved and 274 novel miRNAs belonging to 125 and 250 families, respectively. Sixty-nine conserved miRNAs that are included in 38 families are predicted to have an RNA secondary structure typically found in miRNAs. Many miRNAs were validated by stem-loop RT-PCR. Comparison with the miRNAs in 84 animal species from miRBase showed that the conserved miRNA families we identified are highly conserved in the Arthropoda phylum. Furthermore, miRanda predicted 2701 target genes for 378 miRNAs, which could be categorized into 52 functional groups annotated by gene ontology. The function of miRNA target genes was found to be very similar between conserved and novel miRNAs. This study of miRNAs in L. striatellus will provide new information and enhance the understanding of the role of miRNAs in the regulation of L. striatellus metabolism and development.

cDNA cloning and nucleotide sequence comparison of Chinese hamster metallothionein I and II mRNAs

Energy Technology Data Exchange (ETDEWEB)

Griffith, B B; Walters, R A; Enger, M D; Hildebrand, C E; Griffith, J K

1983-01-01

Polyadenylated RNA was extracted from a cadmium resistant Chinese hamster (CHO) cell line, enriched for metal-induced, abundant RNA sequences and cloned as double-stranded cDNA in the plasmid pBR322. Two cDNA clones, pCHMT1 and pCHMT2, encoding two Chinese hamster isometallothioneins were identified, and the nucleotide sequence of each insert was determined. The two Chinese hamster metallothioneins show nucleotide sequence homologies of 80% in the protein coding region and approximately 35% in both the 5' and 3' untranslated regions. Interestingly, an 8 nucleotide sequence (TGTAAATA) has been conserved in sequence and position in the 3' untranslated regions of each metallothionein mRNA sequenced thus far. Estimated nucleotide substitution rates derived from interspecies comparisons were used to calculate a metallothionein gene duplication time of 45 to 120 million years ago. 39 references, 1 figure, 1 table.

HBVRegDB: Annotation, comparison, detection and visualization of regulatory elements in hepatitis B virus sequences

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Firth Andrew E

2007-12-01

Full Text Available Abstract Background The many Hepadnaviridae sequences available have widely varied functional annotation. The genomes are very compact (~3.2 kb but contain multiple layers of functional regulatory elements in addition to coding regions. Key regions are subject to purifying selection, as mutations in these regions will produce non-functional viruses. Results These genomic sequences have been organized into a structured database to facilitate research at the molecular level. HBVRegDB is a comparative genomic analysis tool with an integrated underlying sequence database. The database contains genomic sequence data from representative viruses. In addition to INSDC and RefSeq annotation, HBVRegDB also contains expert and systematically calculated annotations (e.g. promoters and comparative genome analysis results (e.g. blastn, tblastx. It also contains analyses based on curated HBV alignments. Information about conserved regions – including primary conservation (e.g. CDS-Plotcon and RNA secondary structure predictions (e.g. Alidot – is integrated into the database. A large amount of data is graphically presented using the GBrowse (Generic Genome Browser adapted for analysis of viral genomes. Flexible query access is provided based on any annotated genomic feature. Novel regulatory motifs can be found by analysing the annotated sequences. Conclusion HBVRegDB serves as a knowledge database and as a comparative genomic analysis tool for molecular biologists investigating HBV. It is publicly available and complementary to other viral and HBV focused datasets and tools http://hbvregdb.otago.ac.nz. The availability of multiple and highly annotated sequences of viral genomes in one database combined with comparative analysis tools facilitates detection of novel genomic elements.

Setting conservation priorities.

Science.gov (United States)

Wilson, Kerrie A; Carwardine, Josie; Possingham, Hugh P

2009-04-01

A generic framework for setting conservation priorities based on the principles of classic decision theory is provided. This framework encapsulates the key elements of any problem, including the objective, the constraints, and knowledge of the system. Within the context of this framework the broad array of approaches for setting conservation priorities are reviewed. While some approaches prioritize assets or locations for conservation investment, it is concluded here that prioritization is incomplete without consideration of the conservation actions required to conserve the assets at particular locations. The challenges associated with prioritizing investments through time in the face of threats (and also spatially and temporally heterogeneous costs) can be aided by proper problem definition. Using the authors' general framework for setting conservation priorities, multiple criteria can be rationally integrated and where, how, and when to invest conservation resources can be scheduled. Trade-offs are unavoidable in priority setting when there are multiple considerations, and budgets are almost always finite. The authors discuss how trade-offs, risks, uncertainty, feedbacks, and learning can be explicitly evaluated within their generic framework for setting conservation priorities. Finally, they suggest ways that current priority-setting approaches may be improved.

Tools for integrated sequence-structure analysis with UCSF Chimera

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Huang Conrad C

2006-07-01

Full Text Available Abstract Background Comparing related structures and viewing the structures in the context of sequence alignments are important tasks in protein structure-function research. While many programs exist for individual aspects of such work, there is a need for interactive visualization tools that: (a provide a deep integration of sequence and structure, far beyond mapping where a sequence region falls in the structure and vice versa; (b facilitate changing data of one type based on the other (for example, using only sequence-conserved residues to match structures, or adjusting a sequence alignment based on spatial fit; (c can be used with a researcher's own data, including arbitrary sequence alignments and annotations, closely or distantly related sets of proteins, etc.; and (d interoperate with each other and with a full complement of molecular graphics features. We describe enhancements to UCSF Chimera to achieve these goals. Results The molecular graphics program UCSF Chimera includes a suite of tools for interactive analyses of sequences and structures. Structures automatically associate with sequences in imported alignments, allowing many kinds of crosstalk. A novel method is provided to superimpose structures in the absence of a pre-existing sequence alignment. The method uses both sequence and secondary structure, and can match even structures with very low sequence identity. Another tool constructs structure-based sequence alignments from superpositions of two or more proteins. Chimera is designed to be extensible, and mechanisms for incorporating user-specific data without Chimera code development are also provided. Conclusion The tools described here apply to many problems involving comparison and analysis of protein structures and their sequences. Chimera includes complete documentation and is intended for use by a wide range of scientists, not just those in the computational disciplines. UCSF Chimera is free for non-commercial use and is

Biophysical and structural considerations for protein sequence evolution

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Grahnen Johan A

2011-12-01

Full Text Available Abstract Background Protein sequence evolution is constrained by the biophysics of folding and function, causing interdependence between interacting sites in the sequence. However, current site-independent models of sequence evolutions do not take this into account. Recent attempts to integrate the influence of structure and biophysics into phylogenetic models via statistical/informational approaches have not resulted in expected improvements in model performance. This suggests that further innovations are needed for progress in this field. Results Here we develop a coarse-grained physics-based model of protein folding and binding function, and compare it to a popular informational model. We find that both models violate the assumption of the native sequence being close to a thermodynamic optimum, causing directional selection away from the native state. Sampling and simulation show that the physics-based model is more specific for fold-defining interactions that vary less among residue type. The informational model diffuses further in sequence space with fewer barriers and tends to provide less support for an invariant sites model, although amino acid substitutions are generally conservative. Both approaches produce sequences with natural features like dN/dS Conclusions Simple coarse-grained models of protein folding can describe some natural features of evolving proteins but are currently not accurate enough to use in evolutionary inference. This is partly due to improper packing of the hydrophobic core. We suggest possible improvements on the representation of structure, folding energy, and binding function, as regards both native and non-native conformations, and describe a large number of possible applications for such a model.

Comparative genomics of human and non-human Listeria monocytogenes sequence type 121 strains.

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Kathrin Rychli

Full Text Available The food-borne pathogen Listeria (L. monocytogenes is able to survive for months and even years in food production environments. Strains belonging to sequence type (ST121 are particularly found to be abundant and to persist in food and food production environments. To elucidate genetic determinants characteristic for L. monocytogenes ST121, we sequenced the genomes of 14 ST121 strains and compared them with currently available L. monocytogenes ST121 genomes. In total, we analyzed 70 ST121 genomes deriving from 16 different countries, different years of isolation, and different origins-including food, animal and human ST121 isolates. All ST121 genomes show a high degree of conservation sharing at least 99.7% average nucleotide identity. The main differences between the strains were found in prophage content and prophage conservation. We also detected distinct highly conserved subtypes of prophages inserted at the same genomic locus. While some of the prophages showed more than 99.9% similarity between strains from different sources and years, other prophages showed a higher level of diversity. 81.4% of the strains harbored virtually identical plasmids. 97.1% of the ST121 strains contain a truncated internalin A (inlA gene. Only one of the seven human ST121 isolates encodes a full-length inlA gene, illustrating the need of better understanding their survival and virulence mechanisms.

Conservation of the human integrin-type beta-propeller domain in bacteria.

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Bhanupratap Chouhan

Full Text Available Integrins are heterodimeric cell-surface receptors with key functions in cell-cell and cell-matrix adhesion. Integrin α and β subunits are present throughout the metazoans, but it is unclear whether the subunits predate the origin of multicellular organisms. Several component domains have been detected in bacteria, one of which, a specific 7-bladed β-propeller domain, is a unique feature of the integrin α subunits. Here, we describe a structure-derived motif, which incorporates key features of each blade from the X-ray structures of human αIIbβ3 and αVβ3, includes elements of the FG-GAP/Cage and Ca(2+-binding motifs, and is specific only for the metazoan integrin domains. Separately, we searched for the metazoan integrin type β-propeller domains among all available sequences from bacteria and unicellular eukaryotic organisms, which must incorporate seven repeats, corresponding to the seven blades of the β-propeller domain, and so that the newly found structure-derived motif would exist in every repeat. As the result, among 47 available genomes of unicellular eukaryotes we could not find a single instance of seven repeats with the motif. Several sequences contained three repeats, a predicted transmembrane segment, and a short cytoplasmic motif associated with some integrins, but otherwise differ from the metazoan integrin α subunits. Among the available bacterial sequences, we found five examples containing seven sequential metazoan integrin-specific motifs within the seven repeats. The motifs differ in having one Ca(2+-binding site per repeat, whereas metazoan integrins have three or four sites. The bacterial sequences are more conserved in terms of motif conservation and loop length, suggesting that the structure is more regular and compact than those example structures from human integrins. Although the bacterial examples are not full-length integrins, the full-length metazoan-type 7-bladed β-propeller domains are present, and

Conservation Value

OpenAIRE

Tisdell, Clement A.

2010-01-01

This paper outlines the significance of the concept of conservation value and discusses ways in which it is determined paying attention to views stemming from utilitarian ethics and from deontological ethics. The importance of user costs in relation to economic decisions about the conservation and use of natural resources is emphasised. Particular attention is given to competing views about the importance of conserving natural resources in order to achieve economic sustainability. This then l...

Catalytic center of lecithin:cholesterol acyltransferase: isolation and sequence of diisopropyl fluorophosphate-labeled peptides

Energy Technology Data Exchange (ETDEWEB)

Park, Y.B.; Yueksel, U.G.; Gracy, R.W.; Lacko, A.G.

1987-02-27

Lecithin:cholesterol acyltransferase (LCAT) was purified from hog plasma and subsequently reacted with (/sup 3/H)-Diisopropyl fluorophosphate (DFP). The labeled enzyme was digested with pepsin and the peptides separated by high performance liquid chromatography (HPLC). Two radioactive peptides were isolated, subjected to automated amino acid sequencing and yielded the following data: A) Ile-Ser-Leu-Gly-Ala-Pro-Trp-Gly-Gly-Ser, and B) Tyr-Ile-Phe-Asp-x-Gly-Phe-Pro-Tyr-x-Asp-Pro-Val. Both of these sequences represent very highly conserved regions of the enzyme when compared to the sequence of human LCAT. Peptide (A) is considered to represent the catalytic center of LCAT based on comparisons with data reported in the literature.

Constrained dansyl derivatives reveal bacterial specificity of highly conserved thymidylate synthases.

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Calò, Sanuele; Tondi, Donatella; Ferrari, Stefania; Venturelli, Alberto; Ghelli, Stefano; Costi, Maria Paola

2008-03-25

The elucidation of the structural/functional specificities of highly conserved enzymes remains a challenging area of investigation, and enzymes involved in cellular replication are important targets for functional studies and drug discovery. Thymidylate synthase (TS, ThyA) governs the synthesis of thymidylate for use in DNA synthesis. The present study focused on Lactobacillus casei TS (LcTS) and Escherichia coli TS (EcTS), which exhibit 50 % sequence identity and strong folding similarity. We have successfully designed and validated a chemical model in which linear, but not constrained, dansyl derivatives specifically complement the LcTS active site. Conversely, chemically constrained dansyl derivatives showed up to 1000-fold improved affinity for EcTS relative to the inhibitory activity of linear derivatives. This study demonstrates that the accurate design of small ligands can uncover functional features of highly conserved enzymes.

The complete mitochondrial genome sequence of the world's largest fish, the whale shark (Rhincodon typus), and its comparison with those of related shark species.

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Alam, Md Tauqeer; Petit, Robert A; Read, Timothy D; Dove, Alistair D M

2014-04-10

The whale shark (Rhincodon typus) is the largest extant species of fish, belonging to the order Orectolobiformes. It is listed as a "vulnerable" species on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species, which makes it an important species for conservation efforts. We report here the first complete sequence of the mitochondrial genome (mitogenome) of the whale shark obtained by next-generation sequencing methods. The assembled mitogenome is a 16,875 bp circle, comprising of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region. We also performed comparative analysis of the whale shark mitogenome to the available mitogenome sequences of 17 other shark species, four from the order Orectolobiformes, five from Lamniformes and eight from Carcharhiniformes. The nucleotide composition, number and arrangement of the genes in whale shark mitogenome are the same as found in the mitogenomes of the other members of the order Orectolobiformes and its closest orders Lamniformes and Carcharhiniformes, although the whale shark mitogenome had a slightly longer control region. The availability of mitogenome sequence of whale shark will aid studies of molecular systematics, biogeography, genetic differentiation, and conservation genetics in this species. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of the conservation of synteny between Fugu and human chromosome 12

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Koop Ben F

2003-07-01

Full Text Available Abstract Background The pufferfish Fugu rubripes (Fugu with its compact genome is increasingly recognized as an important vertebrate model for comparative genomic studies. In particular, large regions of conserved synteny between human and Fugu genomes indicate its utility to identify disease-causing genes. The human chromosome 12p12 is frequently deleted in various hematological malignancies and solid tumors, but the actual tumor suppressor gene remains unidentified. Results We investigated approximately 200 kb of the genomic region surrounding the ETV6 locus in Fugu (fETV6 in order to find conserved functional features, such as genes or regulatory regions, that could give insight into the nature of the genes targeted by deletions in human cancer cells. Seven genes were identified near the fETV6 locus. We found that the synteny with human chromosome 12 was conserved, but extensive genomic rearrangements occurred between the Fugu and human ETV6 loci. Conclusion This comparative analysis led to the identification of previously uncharacterized genes in the human genome and some potentially important regulatory sequences as well. This is a good indication that the analysis of the compact Fugu genome will be valuable to identify functional features that have been conserved throughout the evolution of vertebrates.

Genome sequence of the lager brewing yeast, an interspecies hybrid.

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Nakao, Yoshihiro; Kanamori, Takeshi; Itoh, Takehiko; Kodama, Yukiko; Rainieri, Sandra; Nakamura, Norihisa; Shimonaga, Tomoko; Hattori, Masahira; Ashikari, Toshihiko

2009-04-01

This work presents the genome sequencing of the lager brewing yeast (Saccharomyces pastorianus) Weihenstephan 34/70, a strain widely used in lager beer brewing. The 25 Mb genome comprises two nuclear sub-genomes originating from Saccharomyces cerevisiae and Saccharomyces bayanus and one circular mitochondrial genome originating from S. bayanus. Thirty-six different types of chromosomes were found including eight chromosomes with translocations between the two sub-genomes, whose breakpoints are within the orthologous open reading frames. Several gene loci responsible for typical lager brewing yeast characteristics such as maltotriose uptake and sulfite production have been increased in number by chromosomal rearrangements. Despite an overall high degree of conservation of the synteny with S. cerevisiae and S. bayanus, the syntenies were not well conserved in the sub-telomeric regions that contain lager brewing yeast characteristic and specific genes. Deletion of larger chromosomal regions, a massive unilateral decrease of the ribosomal DNA cluster and bilateral truncations of over 60 genes reflect a post-hybridization evolution process. Truncations and deletions of less efficient maltose and maltotriose uptake genes may indicate the result of adaptation to brewing. The genome sequence of this interspecies hybrid yeast provides a new tool for better understanding of lager brewing yeast behavior in industrial beer production.

Unique Trichomonas vaginalis gene sequences identified in multinational regions of Northwest China.

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Liu, Jun; Feng, Meng; Wang, Xiaolan; Fu, Yongfeng; Ma, Cailing; Cheng, Xunjia

2017-07-24

Trichomonas vaginalis (T. vaginalis) is a flagellated protozoan parasite that infects humans worldwide. This study determined the sequence of the 18S ribosomal RNA gene of T. vaginalis infecting both females and males in Xinjiang, China. Samples from 73 females and 28 males were collected and confirmed for infection with T. vaginalis, a total of 110 sequences were identified when the T. vaginalis 18S ribosomal RNA gene was sequenced. These sequences were used to prepare a phylogenetic network. The rooted network comprised three large clades and several independent branches. Most of the Xinjiang sequences were in one group. Preliminary results suggest that Xinjiang T. vaginalis isolates might be genetically unique, as indicated by the sequence of their 18S ribosomal RNA gene. Low migration rate of local people in this province may contribute to a genetic conservativeness of T. vaginalis. The unique genetic feature of our isolates may suggest a different clinical presentation of trichomoniasis, including metronidazole susceptibility, T. vaginalis virus or Mycoplasma co-infection characteristics. The transmission and evolution of Xinjiang T. vaginalis is of interest and should be studied further. More attention should be given to T. vaginalis infection in both females and males in Xinjiang.

Genes with stable DNA methylation levels show higher evolutionary conservation than genes with fluctuant DNA methylation levels.

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Zhang, Ruijie; Lv, Wenhua; Luan, Meiwei; Zheng, Jiajia; Shi, Miao; Zhu, Hongjie; Li, Jin; Lv, Hongchao; Zhang, Mingming; Shang, Zhenwei; Duan, Lian; Jiang, Yongshuai

2015-11-24

Different human genes often exhibit different degrees of stability in their DNA methylation levels between tissues, samples or cell types. This may be related to the evolution of human genome. Thus, we compared the evolutionary conservation between two types of genes: genes with stable DNA methylation levels (SM genes) and genes with fluctuant DNA methylation levels (FM genes). For long-term evolutionary characteristics between species, we compared the percentage of the orthologous genes, evolutionary rate dn/ds and protein sequence identity. We found that the SM genes had greater percentages of the orthologous genes, lower dn/ds, and higher protein sequence identities in all the 21 species. These results indicated that the SM genes were more evolutionarily conserved than the FM genes. For short-term evolutionary characteristics among human populations, we compared the single nucleotide polymorphism (SNP) density, and the linkage disequilibrium (LD) degree in HapMap populations and 1000 genomes project populations. We observed that the SM genes had lower SNP densities, and higher degrees of LD in all the 11 HapMap populations and 13 1000 genomes project populations. These results mean that the SM genes had more stable chromosome genetic structures, and were more conserved than the FM genes.

An efficient binomial model-based measure for sequence comparison and its application.

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Liu, Xiaoqing; Dai, Qi; Li, Lihua; He, Zerong

2011-04-01

Sequence comparison is one of the major tasks in bioinformatics, which could serve as evidence of structural and functional conservation, as well as of evolutionary relations. There are several similarity/dissimilarity measures for sequence comparison, but challenges remains. This paper presented a binomial model-based measure to analyze biological sequences. With help of a random indicator, the occurrence of a word at any position of sequence can be regarded as a random Bernoulli variable, and the distribution of a sum of the word occurrence is well known to be a binomial one. By using a recursive formula, we computed the binomial probability of the word count and proposed a binomial model-based measure based on the relative entropy. The proposed measure was tested by extensive experiments including classification of HEV genotypes and phylogenetic analysis, and further compared with alignment-based and alignment-free measures. The results demonstrate that the proposed measure based on binomial model is more efficient.

Comparative genomic sequence analysis of strawberry and other rosids reveals significant microsynteny

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Abbott Albert

2010-06-01

Full Text Available Abstract Background Fragaria belongs to the Rosaceae, an economically important family that includes a number of important fruit producing genera such as Malus and Prunus. Using genomic sequences from 50 Fragaria fosmids, we have examined the microsynteny between Fragaria and other plant models. Results In more than half of the strawberry fosmids, we found syntenic regions that are conserved in Populus, Vitis, Medicago and/or Arabidopsis with Populus containing the greatest number of syntenic regions with Fragaria. The longest syntenic region was between LG VIII of the poplar genome and the strawberry fosmid 72E18, where seven out of twelve predicted genes were collinear. We also observed an unexpectedly high level of conserved synteny between Fragaria (rosid I and Vitis (basal rosid. One of the strawberry fosmids, 34E24, contained a cluster of R gene analogs (RGAs with NBS and LRR domains. We detected clusters of RGAs with high sequence similarity to those in 34E24 in all the genomes compared. In the phylogenetic tree we have generated, all the NBS-LRR genes grouped together with Arabidopsis CNL-A type NBS-LRR genes. The Fragaria RGA grouped together with those of Vitis and Populus in the phylogenetic tree. Conclusions Our analysis shows considerable microsynteny between Fragaria and other plant genomes such as Populus, Medicago, Vitis, and Arabidopsis to a lesser degree. We also detected a cluster of NBS-LRR type genes that are conserved in all the genomes compared.

Novel Conserved Genotypes Correspond to Antibiotic Resistance Phenotypes of E. coli Clinical Isolates.

Science.gov (United States)

Swick, Michelle C; Evangelista, Michael A; Bodine, Truston J; Easton-Marks, Jeremy R; Barth, Patrick; Shah, Minita J; Bormann Chung, Christina A; Stanley, Sarah; McLaughlin, Stephen F; Lee, Clarence C; Sheth, Vrunda; Doan, Quynh; Hamill, Richard J; Steffen, David; Becnel, Lauren B; Sucgang, Richard; Zechiedrich, Lynn

2013-01-01

Current efforts to understand antibiotic resistance on the whole genome scale tend to focus on known genes even as high throughput sequencing strategies uncover novel mechanisms. To identify genomic variations associated with antibiotic resistance, we employed a modified genome-wide association study; we sequenced genomic DNA from pools of E. coli clinical isolates with similar antibiotic resistance phenotypes using SOLiD technology to uncover single nucleotide polymorphisms (SNPs) unanimously conserved in each pool. The multidrug-resistant pools were genotypically similar to SMS-3-5, a previously sequenced multidrug-resistant isolate from a polluted environment. The similarity was evenly spread across the entire genome and not limited to plasmid or pathogenicity island loci. Among the pools of clinical isolates, genomic variation was concentrated adjacent to previously reported inversion and duplication differences between the SMS-3-5 isolate and the drug-susceptible laboratory strain, DH10B. SNPs that result in non-synonymous changes in gyrA (encoding the well-known S83L allele associated with fluoroquinolone resistance), mutM, ligB, and recG were unanimously conserved in every fluoroquinolone-resistant pool. Alleles of the latter three genes are tightly linked among most sequenced E. coli genomes, and had not been implicated in antibiotic resistance previously. The changes in these genes map to amino acid positions in alpha helices that are involved in DNA binding. Plasmid-encoded complementation of null strains with either allelic variant of mutM or ligB resulted in variable responses to ultraviolet light or hydrogen peroxide treatment as markers of induced DNA damage, indicating their importance in DNA metabolism and revealing a potential mechanism for fluoroquinolone resistance. Our approach uncovered evidence that additional DNA binding enzymes may contribute to fluoroquinolone resistance and further implicate environmental bacteria as a reservoir for

Sequence-structure relationships in RNA loops: establishing the basis for loop homology modeling.

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Schudoma, Christian; May, Patrick; Nikiforova, Viktoria; Walther, Dirk

2010-01-01

The specific function of RNA molecules frequently resides in their seemingly unstructured loop regions. We performed a systematic analysis of RNA loops extracted from experimentally determined three-dimensional structures of RNA molecules. A comprehensive loop-structure data set was created and organized into distinct clusters based on structural and sequence similarity. We detected clear evidence of the hallmark of homology present in the sequence-structure relationships in loops. Loops differing by structures. Thus, our results support the application of homology modeling for RNA loop model building. We established a threshold that may guide the sequence divergence-based selection of template structures for RNA loop homology modeling. Of all possible sequences that are, under the assumption of isosteric relationships, theoretically compatible with actual sequences observed in RNA structures, only a small fraction is contained in the Rfam database of RNA sequences and classes implying that the actual RNA loop space may consist of a limited number of unique loop structures and conserved sequences. The loop-structure data sets are made available via an online database, RLooM. RLooM also offers functionalities for the modeling of RNA loop structures in support of RNA engineering and design efforts.

An atlas of over 90.000 conserved noncoding sequences provides insight into crucifer regulatory regions

NARCIS (Netherlands)

Haudry, A.; Platts, A.E.; Vello, E.; Hoen, D.R.; Leclerq, M.; Williamson, R.J.; Forczek, E.; Joly-Lopez, Z.; Steffen, J.G.; Hazzouri, K.M.; Dewar, K.; Stinchcombe, J.R.; Schoen, D.J.; Wang, X.; Schmutz, J.; Town, C.D.; Edger, P.P.; Pires, J.C.; Schumaker, K.S.; Jarvis, D.E.; Mandakova, T.; Lysak, M.; Bergh, van den E.; Schranz, M.E.; Harrison, P.M.

2013-01-01

Despite the central importance of noncoding DNA to gene regulation and evolution, understanding of the extent of selection on plant noncoding DNA remains limited compared to that of other organisms. Here we report sequencing of genomes from three Brassicaceae species (Leavenworthia alabamica,

The first genome sequence of a metatherian herpesvirus: Macropodid herpesvirus 1.

Science.gov (United States)

Vaz, Paola K; Mahony, Timothy J; Hartley, Carol A; Fowler, Elizabeth V; Ficorilli, Nino; Lee, Sang W; Gilkerson, James R; Browning, Glenn F; Devlin, Joanne M

2016-01-22

While many placental herpesvirus genomes have been fully sequenced, the complete genome of a marsupial herpesvirus has not been described. Here we present the first genome sequence of a metatherian herpesvirus, Macropodid herpesvirus 1 (MaHV-1). The MaHV-1 viral genome was sequenced using an Illumina MiSeq sequencer, de novo assembly was performed and the genome was annotated. The MaHV-1 genome was 140 kbp in length and clustered phylogenetically with the primate simplexviruses, sharing 67% nucleotide sequence identity with Human herpesviruses 1 and 2. The MaHV-1 genome contained 66 predicted open reading frames (ORFs) homologous to those in other herpesvirus genomes, but lacked homologues of UL3, UL4, UL56 and glycoprotein J. This is the first alphaherpesvirus genome that has been found to lack the UL3 and UL4 homologues. We identified six novel ORFs and confirmed their transcription by RT-PCR. This is the first genome sequence of a herpesvirus that infects metatherians, a taxonomically unique mammalian clade. Members of the Simplexvirus genus are remarkably conserved, so the absence of ORFs otherwise retained in eutherian and avian alphaherpesviruses contributes to our understanding of the Alphaherpesvirinae. Further study of metatherian herpesvirus genetics and pathogenesis provides a unique approach to understanding herpesvirus-mammalian interactions.

Discovery of candidate disease genes in ENU-induced mouse mutants by large-scale sequencing, including a splice-site mutation in nucleoredoxin.

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Melissa K Boles

2009-12-01

Full Text Available An accurate and precisely annotated genome assembly is a fundamental requirement for functional genomic analysis. Here, the complete DNA sequence and gene annotation of mouse Chromosome 11 was used to test the efficacy of large-scale sequencing for mutation identification. We re-sequenced the 14,000 annotated exons and boundaries from over 900 genes in 41 recessive mutant mouse lines that were isolated in an N-ethyl-N-nitrosourea (ENU mutation screen targeted to mouse Chromosome 11. Fifty-nine sequence variants were identified in 55 genes from 31 mutant lines. 39% of the lesions lie in coding sequences and create primarily missense mutations. The other 61% lie in noncoding regions, many of them in highly conserved sequences. A lesion in the perinatal lethal line l11Jus13 alters a consensus splice site of nucleoredoxin (Nxn, inserting 10 amino acids into the resulting protein. We conclude that point mutations can be accurately and sensitively recovered by large-scale sequencing, and that conserved noncoding regions should be included for disease mutation identification. Only seven of the candidate genes we report have been previously targeted by mutation in mice or rats, showing that despite ongoing efforts to functionally annotate genes in the mammalian genome, an enormous gap remains between phenotype and function. Our data show that the classical positional mapping approach of disease mutation identification can be extended to large target regions using high-throughput sequencing.

The lytic origin of herpesvirus papio is highly homologous to Epstein-Barr virus ori-Lyt: evolutionary conservation of transcriptional activation and replication signals.

Science.gov (United States)

Ryon, J J; Fixman, E D; Houchens, C; Zong, J; Lieberman, P M; Chang, Y N; Hayward, G S; Hayward, S D

1993-01-01

Herpesvirus papio (HVP) is a B-lymphotropic baboon virus with an estimated 40% homology to Epstein-Barr virus (EBV). We have cloned and sequenced ori-Lyt of herpesvirus papio and found a striking degree of nucleotide homology (89%) with ori-Lyt of EBV. Transcriptional elements form an integral part of EBV ori-Lyt. The promoter and enhancer domains of EBV ori-Lyt are conserved in herpesvirus papio. The EBV ori-Lyt promoter contains four binding sites for the EBV lytic cycle transactivator Zta, and the enhancer includes one Zta and two Rta response elements. All five of the Zta response elements and one of the Rta motifs are conserved in HVP ori-Lyt, and the HVP DS-L leftward promoter and the enhancer were activated in transient transfection assays by the EBV Zta and Rta transactivators. The EBV ori-Lyt enhancer contains a palindromic sequence, GGTCAGCTGACC, centered on a PvuII restriction site. This sequence, with a single base change, is also present in the HVP ori-Lyt enhancer. DNase I footprinting demonstrated that the PvuII sequence was bound by a protein present in a Raji nuclear extract. Mobility shift and competition assays using oligonucleotide probes identified this sequence as a binding site for the cellular transcription factor MLTF. Mutagenesis of the binding site indicated that MLTF contributes significantly to the constitutive activity of the ori-Lyt enhancer. The high degree of conservation of cis-acting signal sequences in HVP ori-Lyt was further emphasized by the finding that an HVP ori-Lyt-containing plasmid was replicated in Vero cells by a set of cotransfected EBV replication genes. The central domain of EBV ori-Lyt contains two related AT-rich palindromes, one of which is partially duplicated in the HVP sequence. The AT-rich palindromes are functionally important cis-acting motifs. Deletion of these palindromes severely diminished replication of an ori-Lyt target plasmid. Images PMID:8389916

Nature and distribution of feline sarcoma virus nucleotide sequences.

Science.gov (United States)

Frankel, A E; Gilbert, J H; Porzig, K J; Scolnick, E M; Aaronson, S A

1979-01-01

The genomes of three independent isolates of feline sarcoma virus (FeSV) were compared by molecular hybridization techniques. Using complementary DNAs prepared from two strains, SM- and ST-FeSV, common complementary DNA'S were selected by sequential hybridization to FeSV and feline leukemia virus RNAs. These DNAs were shown to be highly related among the three independent sarcoma virus isolates. FeSV-specific complementary DNAs were prepared by selection for hybridization by the homologous FeSV RNA and against hybridization by fline leukemia virus RNA. Sarcoma virus-specific sequences of SM-FeSV were shown to differ from those of either ST- or GA-FeSV strains, whereas ST-FeSV-specific DNA shared extensive sequence homology with GA-FeSV. By molecular hybridization, each set of FeSV-specific sequences was demonstrated to be present in normal cat cellular DNA in approximately one copy per haploid genome and was conserved throughout Felidae. In contrast, FeSV-common sequences were present in multiple DNA copies and were found only in Mediterranean cats. The present results are consistent with the concept that each FeSV strain has arisen by a mechanism involving recombination between feline leukemia virus and cat cellular DNA sequences, the latter represented within the cat genome in a manner analogous to that of a cellular gene. PMID:225544

Conserved loci of leaf and stem rust fungi of wheat share synteny interrupted by lineage-specific influx of repeat elements

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Fellers John P

2013-01-01

Full Text Available Abstract Background Wheat leaf rust (Puccinia triticina Eriks; Pt and stem rust fungi (P. graminis f.sp. tritici; Pgt are significant economic pathogens having similar host ranges and life cycles, but different alternate hosts. The Pt genome, currently estimated at 135 Mb, is significantly larger than Pgt, at 88 Mb, but the reason for the expansion is unknown. Three genomic loci of Pt conserved proteins were characterized to gain insight into gene content, genome complexity and expansion. Results A bacterial artificial chromosome (BAC library was made from P. triticina race 1, BBBD and probed with Pt homologs of genes encoding two predicted Pgt secreted effectors and a DNA marker mapping to a region of avirulence. Three BACs, 103 Kb, 112 Kb, and 166 Kb, were sequenced, assembled, and open reading frames were identified. Orthologous genes were identified in Pgt and local conservation of gene order (microsynteny was observed. Pairwise protein identities ranged from 26 to 99%. One Pt BAC, containing a RAD18 ortholog, shares syntenic regions with two Pgt scaffolds, which could represent both haplotypes of Pgt. Gene sequence is diverged between the species as well as within the two haplotypes. In all three BAC clones, gene order is locally conserved, however, gene shuffling has occurred relative to Pgt. These regions are further diverged by differing insertion loci of LTR-retrotransposon, Gypsy, Copia, Mutator, and Harbinger mobile elements. Uncharacterized Pt open reading frames were also found; these proteins are high in lysine and similar to multiple proteins in Pgt. Conclusions The three Pt loci are conserved in gene order, with a range of gene sequence divergence. Conservation of predicted haustoria expressed secreted protein genes between Pt and Pgt is extended to the more distant poplar rust, Melampsora larici-populina. The loci also reveal that genome expansion in Pt is in part due to higher occurrence of repeat-elements in this species.

Assessment of phylogenetic relationship of rare plant species collected from Saudi Arabia using internal transcribed spacer sequences of nuclear ribosomal DNA.

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Al-Qurainy, F; Khan, S; Nadeem, M; Tarroum, M; Alaklabi, A

2013-03-11

The rare and endangered plants of any country are important genetic resources that often require urgent conservation measures. Assessment of phylogenetic relationships and evaluation of genetic diversity is very important prior to implementation of conservation strategies for saving rare and endangered plant species. We used internal transcribed spacer sequences of nuclear ribosomal DNA for the evaluation of sequence identity from the available taxa in the GenBank database by using the Basic Local Alignment Search Tool (BLAST). Two rare plant species viz, Heliotropium strigosum claded with H. pilosum (98% branch support) and Pancratium tortuosum claded with P. tenuifolium (61% branch support) clearly. However, some species, viz Scadoxus multiflorus, Commiphora myrrha and Senecio hadiensis showed close relationships with more than one species. We conclude that nuclear ribosomal internal transcribed spacer sequences are useful markers for phylogenetic study of these rare plant species in Saudi Arabia.

Long-PCR based next generation sequencing of the whole mitochondrial genome of the peacock skate Pavoraja nitida (Elasmobranchii: Arhynchobatidae).

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Yang, Lei; Naylor, Gavin J P

2016-01-01

We determined the complete mitochondrial genome sequence (16,760 bp) of the peacock skate Pavoraja nitida using a long-PCR based next generation sequencing method. It has 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region in the typical vertebrate arrangement. Primers, protocols, and procedures used to obtain this mitogenome are provided. We anticipate that this approach will facilitate rapid collection of mitogenome sequences for studies on phylogenetic relationships, population genetics, and conservation of cartilaginous fishes.

[Sequence analysis of LEAFY homologous gene from Dendrobium moniliforme and application for identification of medicinal Dendrobium].

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Xing, Wen-Rui; Hou, Bei-Wei; Guan, Jing-Jiao; Luo, Jing; Ding, Xiao-Yu

2013-04-01

The LEAFY (LFY) homologous gene of Dendrobium moniliforme (L.) Sw. was cloned by new primers which were designed based on the conservative region of known sequences of orchid LEAFY gene. Partial LFY homologous gene was cloned by common PCR, then we got the complete LFY homologous gene Den LFY by Tail-PCR. The complete sequence of DenLFY gene was 3 575 bp which contained three exons and two introns. Using BLAST method, comparison analysis among the exon of LFY homologous gene indicted that the DenLFY gene had high identity with orchids LFY homologous, including the related fragment of PhalLFY (84%) in Phalaenopsis hybrid cultivar, LFY homologous gene in Oncidium (90%) and in other orchid (over 80%). Using MP analysis, Dendrobium is found to be the sister to Oncidium and Phalaenopsis. Homologous analysis demonstrated that the C-terminal amino acids were highly conserved. When the exons and introns were separately considered, exons and the sequence of amino acid were good markers for the function research of DenLFY gene. The second intron can be used in authentication research of Dendrobium based on the length polymorphism between Dendrobium moniliforme and Dendrobium officinale.

DNA sequence of 15 base pairs is sufficient to mediate both glucocorticoid and progesterone induction of gene expression

International Nuclear Information System (INIS)

Straehle, U.; Klock, G.; Schuetz, G.

1987-01-01

To define the recognition sequence of the glucocorticoid receptor and its relationship with that of the progesterone receptor, oligonucleotides derived from the glucocorticoid response element of the tyrosine aminotransferase gene were tested upstream of a heterologous promoter for their capacity to mediate effects of these two steroids. The authors show that a 15-base-pair sequence with partial symmetry is sufficient to confer glucocorticoid inducibility on the promoter of the herpes simplex virus thymidine kinase gene. The same 15-base-pair sequence mediates induction by progesterone. Point mutations in the recognition sequence affect inducibility by glucocorticoids and progesterone similarly. Together with the strong conservation of the sequence of the DNA-binding domain of the two receptors, these data suggest that both proteins recognize a sequence that is similar, if not the same

An Amyloidogenic Sequence at the N-Terminus of the Androgen Receptor Impacts Polyglutamine Aggregation

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Emmanuel Oppong

2017-06-01

Full Text Available The human androgen receptor (AR is a ligand inducible transcription factor that harbors an amino terminal domain (AR-NTD with a ligand-independent activation function. AR-NTD is intrinsically disordered and displays aggregation properties conferred by the presence of a poly-glutamine (polyQ sequence. The length of the polyQ sequence as well as its adjacent sequence motifs modulate this aggregation property. AR-NTD also contains a conserved KELCKAVSVSM sequence motif that displays an intrinsic property to form amyloid fibrils under mild oxidative conditions. As peptide sequences with intrinsic oligomerization properties are reported to have an impact on the aggregation of polyQ tracts, we determined the effect of the KELCKAVSVSM on the polyQ stretch in the context of the AR-NTD using atomic force microscopy (AFM. Here, we present evidence for a crosstalk between the amyloidogenic properties of the KELCKAVSVSM motif and the polyQ stretch at the AR-NTD.

Functional Advantages of Conserved Intrinsic Disorder in RNA-Binding Proteins.

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Varadi, Mihaly; Zsolyomi, Fruzsina; Guharoy, Mainak; Tompa, Peter

2015-01-01

Proteins form large macromolecular assemblies with RNA that govern essential molecular processes. RNA-binding proteins have often been associated with conformational flexibility, yet the extent and functional implications of their intrinsic disorder have never been fully assessed. Here, through large-scale analysis of comprehensive protein sequence and structure datasets we demonstrate the prevalence of intrinsic structural disorder in RNA-binding proteins and domains. We addressed their functionality through a quantitative description of the evolutionary conservation of disordered segments involved in binding, and investigated the structural implications of flexibility in terms of conformational stability and interface formation. We conclude that the functional role of intrinsically disordered protein segments in RNA-binding is two-fold: first, these regions establish extended, conserved electrostatic interfaces with RNAs via induced fit. Second, conformational flexibility enables them to target different RNA partners, providing multi-functionality, while also ensuring specificity. These findings emphasize the functional importance of intrinsically disordered regions in RNA-binding proteins.

Functional Advantages of Conserved Intrinsic Disorder in RNA-Binding Proteins.

Directory of Open Access Journals (Sweden)

Mihaly Varadi

Full Text Available Proteins form large macromolecular assemblies with RNA that govern essential molecular processes. RNA-binding proteins have often been associated with conformational flexibility, yet the extent and functional implications of their intrinsic disorder have never been fully assessed. Here, through large-scale analysis of comprehensive protein sequence and structure datasets we demonstrate the prevalence of intrinsic structural disorder in RNA-binding proteins and domains. We addressed their functionality through a quantitative description of the evolutionary conservation of disordered segments involved in binding, and investigated the structural implications of flexibility in terms of conformational stability and interface formation. We conclude that the functional role of intrinsically disordered protein segments in RNA-binding is two-fold: first, these regions establish extended, conserved electrostatic interfaces with RNAs via induced fit. Second, conformational flexibility enables them to target different RNA partners, providing multi-functionality, while also ensuring specificity. These findings emphasize the functional importance of intrinsically disordered regions in RNA-binding proteins.