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Mitreva M, Wendl MC, Martin J, Wylie T, Yin Y, Larson A, Parkinson J, Waterston RH, McCarter JP. Codon usage patterns in Nematoda: analysis based on over 25 million codons in thirty-two species. Genome Biol 2006; 7:R75. [PMID: 26271136 PMCID: PMC1779591 DOI: 10.1186/gb-2006-7-8-r75] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Revised: 06/30/2006] [Accepted: 08/14/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Codon usage has direct utility in molecular characterization of species and is also a arker for molecular evolution. To understand codon usage within the diverse phylum Nematoda,we analyzed a total of 265,494 expressed sequence tags (ESTs) from 30 nematode species. The full genomes of Caenorhabditis elegans and C. briggsae were also examined. A total of 25,871,325 codons ere analyzed and a comprehensive codon usage table for all species was generated. This is the first codon usage table available for 24 of these organisms. RESULTS Codon usage similarity in Nematoda usually persists over the breadth of a genus but thenrapidly diminishes even within each clade. Globodera, Meloidogyne, Pristionchus, and Strongyloides have the most highly derived patterns of codon usage. The major factor affecting differences in codon usage between species is the coding sequence GC content, which varies in nematodes from 32%to 51%. Coding GC content (measured as GC3) also explains much of the observed variation in the effective number of codons (R = 0.70), which is a measure of codon bias, and it even accounts for differences in amino acid frequency. Codon usage is also affected by neighboring nucleotides(N1 context). Coding GC content correlates strongly with estimated noncoding genomic GC content (R = 0.92). On examining abundant clusters in five species, candidate optimal codons were identified that may be preferred in highly expressed transcripts. CONCLUSION Evolutionary models indicate that total genomic GC content, probably the product of directional mutation pressure, drives codon usage rather than the converse, a conclusion that is supported by examination of nematode genomes.
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Affiliation(s)
- Makedonka Mitreva
- Genome Sequencing Center, Washington University School of Medicine, St Louis, Missouri 63108, USA
| | - Michael C Wendl
- Genome Sequencing Center, Washington University School of Medicine, St Louis, Missouri 63108, USA
| | - John Martin
- Genome Sequencing Center, Washington University School of Medicine, St Louis, Missouri 63108, USA
| | - Todd Wylie
- Genome Sequencing Center, Washington University School of Medicine, St Louis, Missouri 63108, USA
| | - Yong Yin
- Genome Sequencing Center, Washington University School of Medicine, St Louis, Missouri 63108, USA
| | - Allan Larson
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA
| | - John Parkinson
- Hospital for Sick Children, Toronto, and Departments of Biochemistry/Medical Genetics and Microbiology, University of Toronto, M5G 1X8, Canada
| | - Robert H Waterston
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
| | - James P McCarter
- Genome Sequencing Center, Washington University School of Medicine, St Louis, Missouri 63108, USA
- Divergence Inc., St Louis, Missouri 63141, USA
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Sayers JR, Price HP, Fallon PG, Doenhoff MJ. AGA/AGG codon usage in parasites: implications for gene expression in Escherichia coli. ACTA ACUST UNITED AC 2005; 11:345-6. [PMID: 15275317 DOI: 10.1016/0169-4758(95)80188-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Kovaleva ES, Subbotin SA, Masler EP, Chitwood DJ. Molecular Characterization of the Actin Gene from Cyst Nematodes in Comparison with Those from Other Nematodes. COMP PARASITOL 2005. [DOI: 10.1654/4138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wu Y, Egerton G, Pappin DJC, Harrison RA, Wilkinson MC, Underwood A, Bianco AE. The Secreted Larval Acidic Proteins (SLAPs) of Onchocerca spp. are encoded by orthologues of the alt gene family of Brugia malayi and have host protective potential. Mol Biochem Parasitol 2004; 134:213-24. [PMID: 15003841 DOI: 10.1016/j.molbiopara.2003.12.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Accepted: 12/03/2003] [Indexed: 10/26/2022]
Abstract
Onchocerca volvulus is a tissue-dwelling, vector-borne nematode parasite of humans and the causative agent of onchocerciasis, or 'River Blindness'. Resistance to infection is associated with immune responses to the infective, third-stage (L3) larvae. The antigens of greatest interest for their vaccine potential are surface and secreted molecules. We have previously identified a family of Secreted Larval Acidic Proteins (SLAPs) from the L3 larvae of O. volvulus by biosynthetic labelling. Here, we provide further characterisation of these molecules following cloning and expression of the corresponding cDNAs. Using protein sequencing, we show that SLAPs are members of the alt gene family, first described in the lymphatic filarial parasite, Brugia malayi. Ov-ALT-1 and Ov-ALT-2 correspond with 20 and 18kDa SLAPs. Both proteins are highly acidic and related by sequence, differing chiefly in an 8-amino acid deletion from Ov-ALT-2. By immunochemistry, we confirm that Ov-ALTs are highly stage-specific, being expressed exclusively in late L2 and L3 larvae during growth in the vector. They are synthesised and stored in the glandular oesophagus. Secretion is triggered by the resumption of development in the definitive host and occurs via the pseudocoelom and cuticle. Serological responses in humans to recombinant Ov-ALT-1 indicate that the level of IgG production may be governed by the force of transmission but does not overtly reflect infection status. Immunisation of mice with recombinant Ov-ALT-1 resulted in a modest level of protection against challenge with O. volvulus L3 larvae (P = 0.036). We conclude that Ov-ALT genes, like those of other filariae, are of interest from the standpoint of parasite transmission and infectivity. They may also offer promise as components of a future sub-unit vaccine should the means to enhance protection be achieved.
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Affiliation(s)
- Yang Wu
- Division of Molecular Biology and Immunology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.
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Pogonka T, Oberländer U, Marti T, Lucius R. Acanthocheilonema viteae: characterization of a molt-associated excretory/secretory 18-kDa protein. Exp Parasitol 1999; 93:73-81. [PMID: 10502469 DOI: 10.1006/expr.1999.4445] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Post-invasive third-stage larvae (pL3) of Acanthocheilonema viteae were labeled with [(35)S]-methionine in vivo, and proteins released into the culture supernatant before and during the third molt were analyzed. The molting supernatant (MSN) contained abundant proteins of 14, 18, 29, and 36 kDa. The 14- and 29-kDa proteins were exclusively found in the MSN, while the 18- and 36-kDa proteins were also produced by nonmolting pL3, albeit in much lower quantities. The cDNA for the most abundant protein in the MSN, an 18-kDa protein (Av18), was isolated by polymerase chain reaction (PCR) with reverse transcribed (RT) RNA of pL3, using information of the protein sequence. The Av18 full-length cDNA of 583 base pairs contained the 5' spliced leader sequence of nematodes, an open reading frame of 427 base pairs, and a poly(A) tail in typical distance to a polyadenylation signal. The deduced amino acid sequence encodes for a protein with a calculated size of 15.8 kDa. The N-terminus starts with a hydrophobic signal sequence and a predicted cleavage site after amino acid 20. The Av18 protein showed homologies to the deduced amino acid sequence of the larval transcripts Bm-alt-1 and alt-2 of Brugia malayi and to the Dirofilaria immitis proteins Di20/22 as well as to the Onchocerca volvulus proteins Ov-alt-1 and Ov-alt-2. Av18 is present in all parasite stages within the mammalian host, as determined by immunoblot with sera against the Escherichia coli-expressed protein and RT-PCR experiments. However, it was released into culture medium only by L3 and adult female worms. In female worms Av18 was localized in the cuticular region as demonstrated by immunofluorescent antibody tests using cryosections.
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Affiliation(s)
- T Pogonka
- Department of Molecular Parasitology (Institute of Biology), Humboldt University Berlin, Philippstrasse 13, Berlin, 10115, USA
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Wuitschick JD, Karrer KM. Analysis of genomic G + C content, codon usage, initiator codon context and translation termination sites in Tetrahymena thermophila. J Eukaryot Microbiol 1999; 46:239-47. [PMID: 10377985 DOI: 10.1111/j.1550-7408.1999.tb05120.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In recent years, the amount of molecular sequencing data from Tetrahymena thermophila has dramatically increased. We analyzed G + C content, codon usage, initiator codon context and stop codon sites in the extremely A + T rich genome of this ciliate. Average G + C content was 38% for protein coding regions, 21% for 5' non-coding sequences, 19% for 3' non-coding sequences, 15% for introns, 19% for micronuclear limited sequences and 17% for macronuclear retained sequences flanking micronuclear specific regions. The 75 available T. thermophila protein coding sequences favored codons ending in T and, where possible, avoided those with G in the third position. Highly expressed genes were relatively G + C-rich and exhibited an extremely biased pattern of codon usage while developmentally regulated genes were more A + T-rich and showed less codon usage bias. Regions immediately preceding Tetrahymena translation initiator codons were generally A-rich. For the 60 stop codons examined, the frequency of G in the end + 1 site was much higher than expected whereas C never occupied this position.
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Affiliation(s)
- J D Wuitschick
- Department of Biology, Marquette University, Milwaukee, Wisconsin 53201-1881, USA
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Affiliation(s)
- J G Waterkeyn
- Veterinary Clinical Centre, University of Melbourne, Victoria, Australia.
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Abstract
Coxiella burnetii, the causative agent of Q fever, is an obligate intracellular bacterium. With the development of molecular biology techniques, there have been increasing efforts on gene cloning and other genetic analyses of this organism. In this report, we tabulate the codon usage (CU) and nucleotide (nt) co-occurrence in C. burnetii, based on available nt sequence data. The average G+C content of the C. burnetii genome is 42.4%, where the G+C content is 42.7% for the chromosome and 38.7% for the plasmid. In comparison to Escherichia coli, there is biased CU. Some codons are frequently used in C. burnetii, but rarely used in E. coli and vice versa. Plasmid genes prefer A or T at the first or third position of a codon. However, TAA remains the most used stop codon. In the AT-rich DNA of C. burnetii, A or T tend to occur together, forming A or T tracks.
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Affiliation(s)
- Z Lin
- Department of Microbiology, Washington State University, Pullman 99164-4233, USA
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Wu Y, Adam R, Williams SA, Bianco AE. Chitinase genes expressed by infective larvae of the filarial nematodes, Acanthocheilonema viteae and Onchocerca volvulus. Mol Biochem Parasitol 1996; 75:207-19. [PMID: 8992319 DOI: 10.1016/0166-6851(95)02529-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
State-specific products of 220 and 75 kDa were identified by metabolic labelling of infective larvae of the filarial nematode Acanthocheilonema viteae in ticks. Synthesis was temperature sensitive, occurring at 27 degrees C but not at 37 degrees C. These products were secreted 3-6 days after leaving the vector during post-infective development, but subsequent expression was not detected. The smaller protein with a pI of 6.2, was purified by two-dimensional electrophoresis and the N-terminal amino acid sequence was derived. This provisionally identified the protein as a chitinase, which was confirmed biochemically by glycol-chitin substrate gel electrophoresis. The polymerase chain reaction was used to amplify a product from a cDNA library of A. viteae infective larvae. The nucleotide sequence codes for a putative signal peptide of 20 amino acids and a mature protein of 504 residues (Mr 56 kDa), exhibiting 69% identity (81% similarity allowing for conservative substitutions) with the MF1 chitinase described from microfilariae of Brugia malayi. N-linked glycosylation may account for some, or all, of the discrepancy in Mr between the predicted polypeptide and the native parasite product (75 kDa). Primers based on the A. viteae sequence were used to amplify a related sequence from a cDNA library of Onchocerca volvulus infective larvae. The O. volvulus cDNA codes for a 20-amino acid signal peptide followed by 477 residues with an Mr of 54 kDa, and shares 67% identity with the A. viteae chitinase (80% similarity allowing for conservative substitutions) and 69% identity with the B. malayi MF1 molecule. It is proposed that chitinases expressed by infective stages of these filarial nematodes may play a role in ecdysis during post-infective development.
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Affiliation(s)
- Y Wu
- Liverpool School of Tropical Medicine, UK
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Yates RA, Tuan RS, Shepley KJ, Unnasch TR. Characterization of genes encoding members of the nuclear hormone receptor superfamily from Onchocerca volvulus. Mol Biochem Parasitol 1995; 70:19-31. [PMID: 7637701 DOI: 10.1016/0166-6851(95)00018-v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Several lines of evidence suggest that molting in parasitic nematodes is controlled through the action of steroid molting hormones, or ecdysones. In other organisms, the central mediator of steroid hormone action is the hormone receptor. These receptor molecules are members of a superfamily of proteins called the nuclear hormone receptor family. Using an oligonucleotide derived from the amino-acid sequence of the Drosophila melanogaster ecdysone receptor, genes encoding homologues of the nuclear hormone receptor family were identified in the genome of the human filarial parasite Onchocerca volvulus. The O. volvulus genome contains at least three genes that encode putative members of the nuclear hormone receptor superfamily. A complete cDNA for one of these genes, designated OvNHR-1, has been isolated and characterized. The OvNHR-1 cDNA was 2378 bp in length, and contained a single open reading frame of 1104 bp. The open reading frame encoded a peptide with all of the features characteristic of a member of the nuclear hormone receptor superfamily of proteins. OVNHR-1 appeared to be encoded by a single-copy gene. Expression of the mRNA corresponding to OvNHR-1 was developmentally regulated, with maximal expression occurring during early embryogenesis. The polypeptide encoded by the OvNHR-1 open reading frame is antigenic in a minority of individuals exposed to O. volvulus.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Helminth/biosynthesis
- Antigens, Helminth/genetics
- Antigens, Helminth/immunology
- Base Sequence
- Cell Nucleus/metabolism
- Cloning, Molecular
- DNA, Complementary/genetics
- Ecdysone/metabolism
- Escherichia coli
- Female
- Gene Expression Regulation, Developmental
- Genes, Helminth
- Helminth Proteins/biosynthesis
- Helminth Proteins/genetics
- Helminth Proteins/immunology
- In Situ Hybridization
- Molecular Sequence Data
- Multigene Family
- Onchocerca volvulus/embryology
- Onchocerca volvulus/genetics
- Onchocerca volvulus/growth & development
- Onchocerca volvulus/immunology
- Open Reading Frames
- Phylogeny
- Receptors, Cytoplasmic and Nuclear/biosynthesis
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/immunology
- Receptors, Steroid/biosynthesis
- Receptors, Steroid/genetics
- Receptors, Steroid/immunology
- Recombinant Fusion Proteins/biosynthesis
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Affiliation(s)
- R A Yates
- Division of Geographic Medicine, University of Alabama at Birmingham 35294, USA
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11
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Ellis J, Morrison DA, Kalinna B. Comparison of the patterns of codon usage and bias between Brugia, Echinococcus, Onchocerca and Schistosoma species. Parasitol Res 1995; 81:388-93. [PMID: 7501637 DOI: 10.1007/bf00931499] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Patterns of codon usage and bias were compared among taxa of the genera Brugia, Echinococcus, Onchocerca and Schistosoma by metric multidimensional scaling and three commonly used indices of bias: Nc, GC3S and B. The overall codon usage for each taxon was compared, as was the codon usage for each individual gene within the taxa. Differences in the patterns of codon usage observed between taxa were dependent on the overall base composition of the genes analysed. The codon usage of Echinococcus was distinct from that of the other taxa. Furthermore, the pattern of codon usage detected by the average codon usage summed across all genes for each taxon was not shown by all genes from that taxon.
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Affiliation(s)
- J Ellis
- Faculty of Science, University of Technology Sydney, New South Wales, Australia
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12
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Ajuh PM, Egwang TG. Cloning of a cDNA encoding a putative nicotinic acetylcholine receptor subunit of the human filarial parasite Onchocerca volvulus. Gene 1994; 144:127-9. [PMID: 8026747 DOI: 10.1016/0378-1119(94)90216-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A partial cDNA clone encoding a putative nicotinic acetylcholine receptor (ACHR) subunit of the human filarial parasite, Onchocerca volvulus, has been isolated and sequenced. A truncated open reading frame of 1308 bp capable of encoding 436 amino acids with a calculated M(r) of 51,209 was identified. The absence of the double cysteine residues necessary for neurotransmitter binding indicates that the cloned ACHR is a non-alpha subunit.
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Affiliation(s)
- P M Ajuh
- Department of Filarial Molecular Biology, Centre International de Recherches Médicales de Franceville, Gabon
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Affiliation(s)
- M P Hammond
- Department of Biochemistry, University of the West Indies, Mona, Kingston, Jamaica
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