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1.
Folia Biol (Praha) ; 65(5-6): 212-220, 2019.
Article in English | MEDLINE | ID: mdl-32362304

ABSTRACT

Breast cancer survival prediction can have an extreme effect on selection of best treatment protocols. Many approaches such as statistical or machine learning models have been employed to predict the survival prospects of patients, but newer algorithms such as deep learning can be tested with the aim of improving the models and prediction accuracy. In this study, we used machine learning and deep learning approaches to predict breast cancer survival in 4,902 patient records from the University of Malaya Medical Centre Breast Cancer Registry. The results indicated that the multilayer perceptron (MLP), random forest (RF) and decision tree (DT) classifiers could predict survivorship, respectively, with 88.2 %, 83.3 % and 82.5 % accuracy in the tested samples. Support vector machine (SVM) came out to be lower with 80.5 %. In this study, tumour size turned out to be the most important feature for breast cancer survivability prediction. Both deep learning and machine learning methods produce desirable prediction accuracy, but other factors such as parameter configurations and data transformations affect the accuracy of the predictive model.


Subject(s)
Breast Neoplasms/mortality , Deep Learning , Adult , Aged , Aged, 80 and over , Calibration , Decision Trees , Demography , Female , Humans , Middle Aged , Neural Networks, Computer , Support Vector Machine , Survival Analysis , Young Adult
2.
Folia Morphol (Warsz) ; 77(2): 179-193, 2018.
Article in English | MEDLINE | ID: mdl-28868609

ABSTRACT

Identification of taxonomy at a specific level is time consuming and reliant upon expert ecologists. Hence the demand for automated species identification incre-ased over the last two decades. Automation of data classification is primarily focussed on images while incorporating and analysing image data has recently become easier due to developments in computational technology. Research ef-forts on identification of species include specimens' image processing, extraction of identical features, followed by classifying them into correct categories. In this paper, we discuss recent automated species identification systems, mainly for categorising and evaluating their methods. We reviewed and compared different methods in step by step scheme of automated identification and classification systems of species images. The selection of methods is influenced by many variables such as level of classification, number of training data and complexity of images. The aim of writing this paper is to provide researchers and scientists an extensive background study on work related to automated species identification, focusing on pattern recognition techniques in building such systems for biodiversity studies. (Folia Morphol 2018; 77, 2: 179-193).


Subject(s)
Biodiversity , Image Processing, Computer-Assisted
3.
Theor Appl Genet ; 126(8): 2093-101, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23689743

ABSTRACT

We used the Roche-454 platform to sequence from normalized cDNA libraries from each of two inbred lines of onion (OH1 and 5225). From approximately 1.6 million reads from each inbred, 27,065 and 33,254 cDNA contigs were assembled from OH1 and 5225, respectively. In total, 3,364 well supported single nucleotide polymorphisms (SNPs) on 1,716 cDNA contigs were identified between these two inbreds. One SNP on each of 1,256 contigs was randomly selected for genotyping. OH1 and 5225 were crossed and 182 gynogenic haploids extracted from hybrid plants were used for SNP mapping. A total of 597 SNPs segregated in the OH1 × 5225 haploid family and a genetic map of ten linkage groups (LOD ≥8) was constructed. Three hundred and thirty-nine of the newly identified SNPs were also mapped using a previously developed segregating family from BYG15-23 × AC43, and 223 common SNPs were used to join the two maps. Because these new SNPs are in expressed regions of the genome and commonly occur among onion germplasms, they will be useful for genetic mapping, gene tagging, marker-aided selection, quality control of seed lots, and fingerprinting of cultivars.


Subject(s)
Chromosome Mapping/methods , Chromosomes, Plant/genetics , Genome, Plant/genetics , Onions/genetics , Polymorphism, Single Nucleotide , Genetic Linkage , Genetic Variation , Genotype , Sequence Analysis, DNA , Transcriptome/genetics
4.
Mol Breed ; 26(3): 393-408, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20976284

ABSTRACT

Pigeonpea (Cajanus cajan), an important food legume crop in the semi-arid regions of the world and the second most important pulse crop in India, has an average crop productivity of 780 kg/ha. The relatively low crop yields may be attributed to non-availability of improved cultivars, poor crop husbandry and exposure to a number of biotic and abiotic stresses in pigeonpea growing regions. Narrow genetic diversity in cultivated germplasm has further hampered the effective utilization of conventional breeding as well as development and utilization of genomic tools, resulting in pigeonpea being often referred to as an 'orphan crop legume'. To enable genomics-assisted breeding in this crop, the pigeonpea genomics initiative (PGI) was initiated in late 2006 with funding from Indian Council of Agricultural Research under the umbrella of Indo-US agricultural knowledge initiative, which was further expanded with financial support from the US National Science Foundation's Plant Genome Research Program and the Generation Challenge Program. As a result of the PGI, the last 3 years have witnessed significant progress in development of both genetic as well as genomic resources in this crop through effective collaborations and coordination of genomics activities across several institutes and countries. For instance, 25 mapping populations segregating for a number of biotic and abiotic stresses have been developed or are under development. An 11X-genome coverage bacterial artificial chromosome (BAC) library comprising of 69,120 clones have been developed of which 50,000 clones were end sequenced to generate 87,590 BAC-end sequences (BESs). About 10,000 expressed sequence tags (ESTs) from Sanger sequencing and ca. 2 million short ESTs by 454/FLX sequencing have been generated. A variety of molecular markers have been developed from BESs, microsatellite or simple sequence repeat (SSR)-enriched libraries and mining of ESTs and genomic amplicon sequencing. Of about 21,000 SSRs identified, 6,698 SSRs are under analysis along with 670 orthologous genes using a GoldenGate SNP (single nucleotide polymorphism) genotyping platform, with large scale SNP discovery using Solexa, a next generation sequencing technology, is in progress. Similarly a diversity array technology array comprising of ca. 15,000 features has been developed. In addition, >600 unique nucleotide binding site (NBS) domain containing members of the NBS-leucine rich repeat disease resistance homologs were cloned in pigeonpea; 960 BACs containing these sequences were identified by filter hybridization, BES physical maps developed using high information content fingerprinting. To enrich the genomic resources further, sequenced soybean genome is being analyzed to establish the anchor points between pigeonpea and soybean genomes. In addition, Solexa sequencing is being used to explore the feasibility of generating whole genome sequence. In summary, the collaborative efforts of several research groups under the umbrella of PGI are making significant progress in improving molecular tools in pigeonpea and should significantly benefit pigeonpea genetics and breeding. As these efforts come to fruition, and expanded (depending on funding), pigeonpea would move from an 'orphan legume crop' to one where genomics-assisted breeding approaches for a sustainable crop improvement are routine.

5.
Genet Mol Res ; 9(1): 167-75, 2010 Feb 02.
Article in English | MEDLINE | ID: mdl-20198573

ABSTRACT

TGA factors play a key role in plant defense by binding to the promoter region of defense genes, inducing expression. Salicylic acid (SA) induces the expression of the gene encoding NIMIN-1, which interacts with NPR1/NIM1, a key regulator of systemic acquired resistance. We investigated whether the TGA2-binding motif TGACG located upstream of the NIMIN-1 gene is necessary for SA induction of NIMIN-1 expression. A mutated version of the NIMIN-1 promoter was created by site-directed mutagenesis. We generated T-DNA constructs in which native NIMIN-1 and mutated promoters were fused to green fluorescent protein and beta-glucuronidase reporters. We produced transgenic Arabidopsis plants and observed NIMIN-1 promoter-driven green fluorescent protein expression in the roots, petiole and leaves. Constructs were agroinfiltrated into the leaves for transient quantitative assays of gene expression. Using quantitative real-time RT-PCR, we characterized the normal gene response to SA and compared it to the response of the mutant version of the NIMIN-1 promoter. Both the native NIMIN-1 construct and an endogenous copy of NIMIN-1 were induced by SA. However, the mutated promoter construct was much less sensitive to SA than the native NIMIN-1 promoter, indicating that this TGA2-binding motif is directly involved in the modulation of SA-induced NIMIN-1 expression in Arabidopsis.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Arabidopsis/drug effects , Arabidopsis/genetics , Basic-Leucine Zipper Transcription Factors/metabolism , Carrier Proteins/genetics , Gene Expression Regulation, Plant/drug effects , Nuclear Proteins/metabolism , Promoter Regions, Genetic , Salicylic Acid/pharmacology , Base Sequence , Binding Sites , Carrier Proteins/metabolism , Green Fluorescent Proteins/metabolism , Molecular Sequence Data , Mutation/genetics , Plants, Genetically Modified , Protein Binding/drug effects , Transcription Factors
6.
Fungal Genet Biol ; 44(8): 799-807, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17300967

ABSTRACT

We investigated the sexual reproductive mode of the two most important etiological agents of soybean sudden death syndrome, Fusarium tucumaniae and Fusarium virguliforme. F. tucumaniae sexual crosses often were highly fertile, making it possible to assign mating type and assess female fertility in 24 South American isolates. These crosses produced red perithecia and oblong-elliptical ascospores, as is typical for sexual members of the F. solani species complex. Genotyping of progeny from three F. tucumaniae crosses confirmed that sexual recombination had occurred. In contrast, pairings among 17 U.S. F. virguliforme isolates never produced perithecia. Inter-species crosses between F. tucumaniae and F. virguliforme, in which infertile perithecia were induced only in one of the two F. tucumaniae mating types, suggest that all U.S. F. virguliforme isolates are of a single mating type. We conclude that the F. tucumaniae life cycle in S. America includes a sexual reproductive mode, and thus this species has greater potential for rapid evolution than the F. virguliforme population in the U.S., which may be exclusively asexual.


Subject(s)
Fusarium/growth & development , Fusarium/physiology , Glycine max/microbiology , Plant Diseases/microbiology , Crosses, Genetic , DNA, Fungal/genetics , Fusarium/ultrastructure , Genotype , Microscopy, Electron, Scanning , Polymerase Chain Reaction , Spores, Fungal/cytology , Spores, Fungal/ultrastructure
7.
Cytogenet Genome Res ; 119(3-4): 268-74, 2007.
Article in English | MEDLINE | ID: mdl-18253041

ABSTRACT

Although the nuclear genome of banana (Musa spp.) is relatively small (1C approximately 610 Mbp for M. acuminata), the results obtained from other sequenced genomes suggest that more than half of the banana genome may be composed of repetitive and non-coding DNA sequences. Knowledge of repetitive DNA can facilitate mapping of important traits, phylogenetic studies, BAC-based physical mapping, and genome sequencing/annotation. However, only a few repetitive DNA sequences have been characterized in banana. In this work, we used DNA reassociation kinetics to isolate the highly repeated fraction of the banana genome (M. acuminata 'Calcutta 4'). Two libraries, one prepared from Cot

Subject(s)
DNA, Plant/genetics , DNA, Plant/isolation & purification , Genome, Plant/genetics , Musa/genetics , Repetitive Sequences, Nucleic Acid/genetics , Base Sequence , Chromosomes, Artificial, Bacterial , Clone Cells , DNA, Ribosomal/genetics , Gene Dosage , Gene Library , Primed In Situ Labeling , Sequence Homology, Nucleic Acid , Tandem Repeat Sequences
8.
Mol Genet Genomics ; 276(6): 503-16, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17024428

ABSTRACT

The rhg1 gene or genes lie at a recessive or co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines I.). The aim here was to identify nucleotide changes within a candidate gene found at the rhg1 locus that were capable of altering resistance to Hg types 0 (race 3). A 1.5 +/- 0.25 cM region of chromosome 18 (linkage group G) was shown to encompass rhg1 using recombination events from four near isogenic line populations and nine DNA markers. The DNA markers anchored two bacterial artificial chromosome (BAC) clones 21d9 and 73p6. A single receptor like kinase (RLK; leucine rich repeat-transmembrane-protein kinase) candidate resistance gene was amplified from both BACs using redundant primers. The DNA sequence showed nine alleles of the RLK at Rhg1 in the soybean germplasm. Markers designed to detect alleles showed perfect association between allele 1 and resistance to soybean cyst nematode Hg types 0 in three segregating populations, fifteen additional selected recombination events and twenty-two Plant Introductions. A quantitative trait nucleotide (QTN) [corrected] in the RLK at rhg1 was inferred that alters A87 to V87 in the context of H274 rather than N274. [corrected] Contiguous DNA sequence of 315 kbp of chromosome 18 (about 2 cM) contained additional gene candidates that may modulate resistance to other Hg-types including a variant laccase, a hydrogen-sodium ion antiport and two proteins of unknown function. A molecular basis for recessive and co-dominant resistance that involves interactions among paralagous disease-resistance genes was inferred that would improve methods for developing new nematode-resistant soybean cultivars.


Subject(s)
Chromosome Mapping , Genes, Plant/genetics , Glycine max/genetics , Immunity, Innate/genetics , Plant Diseases/parasitology , Tylenchoidea , Animals , Base Sequence , Blotting, Southern , Chromosomes, Artificial, Bacterial , Crosses, Genetic , Genomics , Microsatellite Repeats/genetics , Molecular Sequence Data , Plant Diseases/genetics , Sequence Analysis, DNA
9.
Genome ; 48(1): 125-38, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15729404

ABSTRACT

Candidate genes were identified for two loci, QRfs2 providing resistance to the leaf scorch called soybean (Glycine max (L.) Merr.) sudden death syndrome (SDS) and QRfs1 providing resistance to root infection by the causal pathogen Fusarium solani f.sp. glycines. The 7.5 +/- 0.5 cM region of chromosome 18 (linkage group G) was shown to encompass a cluster of resistance loci using recombination events from 4 near-isogenic line populations and 9 DNA markers. The DNA markers anchored 9 physical map contigs (7 are shown on the soybean Gbrowse, 2 are unpublished), 45 BAC end sequences (41 in Gbrowse), and contiguous DNA sequences of 315, 127, and 110 kbp. Gene density was high at 1 gene per 7 kbp only around the already sequenced regions. Three to 4 gene-rich islands were inferred to be distributed across the entire 7.5 cM or 3.5 Mbp showing that genes are clustered in the soybean genome. Candidate resistance genes were identified and a molecular basis for interactions among the disease resistance genes in the cluster inferred.


Subject(s)
Genes, Plant/genetics , Genome, Plant , Glycine max/genetics , Glycine max/microbiology , Plant Diseases/genetics , Plant Diseases/microbiology , Contig Mapping , Fusarium/physiology , Genomics , Physical Chromosome Mapping
10.
Biotechniques ; 33(4): 924-30, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12398202

ABSTRACT

In most microarray assays, labeled cDNA molecules derived from reference and query RNA samples are co-hybridized to probes arrayed on a glass surface. Gene expression profiles are then calculated for each gene based on the relative hybridization intensities measured between the two samples. The most commonly used reference samples are typically isolates from a single representative RNA source (RNA-0) or pooled mixtures of RNA derived from a plurality of sources (RNA-p). Genomic DNA offers an alternative reference nucleic acid with a number of potential advantages, including stability, reproducibility, and a potentially uniform representation of all genes, as each unique gene should have equal representation in a haploid genome. Using hydrogen peroxide-treated Arabidopsis thaliana plants as a model, we evaluated genomic DNA and RNA-p as reference samples and compared expression levels inferred through the reference relative to unexposed plants with expression levels measured directly using an RNA-0 reference. Our analysis demonstrates that while genomic DNA can serve as a reasonable reference source for microarray assays, a much greater correlation with direct measurements can be achieved using an RNA-based reference sample.


Subject(s)
Gene Expression Profiling/methods , Oligonucleotide Array Sequence Analysis , Reference Standards , Arabidopsis/drug effects , Arabidopsis/genetics , DNA, Complementary/genetics , DNA, Plant/genetics , Genome, Plant , HSP70 Heat-Shock Proteins/genetics , Hydrogen Peroxide/pharmacology , In Situ Hybridization, Fluorescence , Nucleic Acid Hybridization , Oligonucleotide Array Sequence Analysis/standards , RNA/genetics , RNA, Plant/isolation & purification
11.
Proc Natl Acad Sci U S A ; 98(9): 5099-103, 2001 Apr 24.
Article in English | MEDLINE | ID: mdl-11309509

ABSTRACT

Previously conducted sequence analysis of Arabidopsis thaliana (ecotype Columbia-0) reported an insertion of 270-kb mtDNA into the pericentric region on the short arm of chromosome 2. DNA fiber-based fluorescence in situ hybridization analyses reveal that the mtDNA insert is 618 +/- 42 kb, approximately 2.3 times greater than that determined by contig assembly and sequencing analysis. Portions of the mitochondrial genome previously believed to be absent were identified within the insert. Sections of the mtDNA are repeated throughout the insert. The cytological data illustrate that DNA contig assembly by using bacterial artificial chromosomes tends to produce a minimal clone path by skipping over duplicated regions, thereby resulting in sequencing errors. We demonstrate that fiber-fluorescence in situ hybridization is a powerful technique to analyze large repetitive regions in the higher eukaryotic genomes and is a valuable complement to ongoing large genome sequencing projects.


Subject(s)
Arabidopsis/genetics , Chromosomes/genetics , DNA, Mitochondrial/genetics , In Situ Hybridization, Fluorescence/methods , Mutagenesis, Insertional/genetics , Repetitive Sequences, Nucleic Acid/genetics , Artifacts , Chromosomes, Artificial, Bacterial/genetics , Contig Mapping , Evolution, Molecular , Genome, Plant , Models, Genetic , Sequence Analysis, DNA/methods
12.
Nucleic Acids Res ; 29(1): 102-5, 2001 Jan 01.
Article in English | MEDLINE | ID: mdl-11125061

ABSTRACT

Arabidopsis thaliana, a small annual plant belonging to the mustard family, is the subject of study by an estimated 7000 researchers around the world. In addition to the large body of genetic, physiological and biochemical data gathered for this plant, it will be the first higher plant genome to be completely sequenced, with completion expected at the end of the year 2000. The sequencing effort has been coordinated by an international collaboration, the Arabidopsis Genome Initiative (AGI). The rationale for intensive investigation of Arabidopsis is that it is an excellent model for higher plants. In order to maximize use of the knowledge gained about this plant, there is a need for a comprehensive database and information retrieval and analysis system that will provide user-friendly access to Arabidopsis information. This paper describes the initial steps we have taken toward realizing these goals in a project called The Arabidopsis Information Resource (TAIR) (www.arabidopsis.org).


Subject(s)
Arabidopsis/genetics , Databases, Factual , Chromosome Mapping , Genome, Plant , Information Services , Information Storage and Retrieval , Internet
13.
Pharm Res ; 16(11): 1775-80, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10571286

ABSTRACT

PURPOSE: To investigate the use of buccal bioadhesive device in targeting controlled drug delivery to the gastrointestinal tract. METHODS: A three-leg crossover study was designed to evaluate the application of buccal bioadhesive device for providing controlled drug delivery to the gastrointestinal tract of a model drug cyanocobalamin in four healthy adult male beagle dogs. RESULTS: In vitro dissolution studies using deionized water as the medium indicated that 100% of the drug was released within 15 min from a immediate release oral capsule formulation, whereas 90% of the drug was released within a period of 18 hrs from a buccal bioadhesive device formulation. Drug release from the buccal bioadhesive devices appeared to follow Higuchi's square root of time dependent model. The terminal half-life of the drug following I.V. administration in four dogs was found to be 16.4+/-2.4 hrs. Following immediate release oral capsule administration of the drug Cmax, tmax and bioavailability were 2333+/-1469 ng/L, 2.5+/-1.0 hrs and 14.1+/-7.9%, respectively. Following buccal bioadhesive device administration of the drug Cmax, t(max) and bioavailability were 4154+/-1096 ng/L, 11+/-1.2 hrs and 35.8+/-4.1%, respectively. Significantly higher bioavailability of the drug was observed with the buccal bioadhesive device administration when compared to the immediate release oral capsule. CONCLUSIONS: The buccal bioadhesive device appears to improve the oral bioavailability of cyanocobalamin by providing controlled delivery of the drug to the gastrointestinal tract.


Subject(s)
Adhesives/chemistry , Drug Delivery Systems/methods , Polyethylene Glycols/chemistry , Vitamin B 12/pharmacokinetics , Administration, Buccal , Animals , Biological Availability , Capsules , Cross-Over Studies , Delayed-Action Preparations , Dogs , In Vitro Techniques , Male , Solubility , Tissue Adhesions , Vitamin B 12/administration & dosage , Vitamin B 12/blood
14.
Nature ; 402(6763): 761-8, 1999 Dec 16.
Article in English | MEDLINE | ID: mdl-10617197

ABSTRACT

Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2.


Subject(s)
Arabidopsis/genetics , Chromosome Mapping , DNA, Plant , Genes, Plant , Cell Nucleus/genetics , Centromere , Evolution, Molecular , Gene Duplication , Genes, Plant/physiology , Mitochondria/genetics , Molecular Sequence Data , Plant Proteins/genetics , Plant Proteins/physiology , Sequence Analysis, DNA
15.
Plant Physiol ; 112(2): 735-45, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8883385

ABSTRACT

Two mutants of Arabidopsis thaliana that are resistant to growth inhibition by indole-3-acetic acid (IAA)-phenylalanine have been isolated. Both mutants were 2- to 3-fold more resistant than wild type to inhibition by IAA-phenylalanine, IAA-alanine, and IAA-glycine in root growth assays. The mutant icr1 (but not icr2) also shows some resistance to IAA-aspartate. Studies using 3H-labeled IAA-phenylalanine showed that the uptake of conjugate from the medium by icr1 was the same as wild type and was reduced by about 25% in icr2. No differences in hydrolysis of the exogenous conjugate were detected between the mutants and their wild-type parents. There was no significant metabolism of the IAA released from the [3H]IAA-phenylalanine, whereas exogenous [3H]IAA was rapidly metabolized to two unidentified products considerably more polar than IAA. Analysis of a cross between icr1 and icr2 indicated that these mutations were at distinct loci and that their effects were additive, and preliminary mapping data indicated that icr1 and icr2 were located at the top and bottom of chromosome V, respectively.


Subject(s)
Amino Acids/pharmacology , Arabidopsis/genetics , Drug Resistance/genetics , Indoleacetic Acids/pharmacology , Mutation , Plant Growth Regulators/pharmacology , Amino Acids/chemistry , Amino Acids/metabolism , Arabidopsis/drug effects , Biological Transport , Chromosome Mapping , Crosses, Genetic , Genes, Plant , Growth Inhibitors/pharmacology , Hydrolysis , Indoleacetic Acids/chemistry , Indoleacetic Acids/metabolism
16.
Plant Physiol ; 110(4): 1159-65, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8934623

ABSTRACT

A mutant of Arabidopsis thaliana, amt-1, was previously selected for resistance to growth inhibition by the tryptophan analog alpha-methyltryptophan. This mutant had elevated tryptophan levels and exhibited higher anthranilate synthase (AS) activity that showed increased resistance to feedback inhibition by tryptophan. In this study, extracts of the mutant callus exhibited higher AS activity than wild-type callus when assayed with either glutamine or ammonium sulfate as amino donor, thus suggesting that elevated AS activity in the mutant was due to an alteration in the alpha subunit of the enzyme. The mutant also showed cross-resistance to 5-methylanthranilate and 6-methylanthranilate and mapped to chromosome V at or close to ASA1 (a gene encoding the AS alpha subunit). ASA1 mRNA and protein levels were similar in mutant and wild-type leaf extracts. Levels of ASA1 mRNA and protein were also similar in callus cultures of mutant and wild type, although the levels in callus were higher than in leaf tissue. Sequencing of the ASA1 gene from amt-1 revealed a G to A transition relative to the wild-type gene that would result in the substitution of an asparagine residue in place of aspartic acid at position 341 in the predicted amino acid sequence of the ASA1 protein. The mutant allele in strain amt-1 has been renamed trp5-1.


Subject(s)
Arabidopsis/genetics , Plant Growth Regulators/pharmacology , Tryptophan/analogs & derivatives , Tryptophan/metabolism , Amino Acid Sequence , Anthranilate Synthase/genetics , Anthranilate Synthase/metabolism , Arabidopsis/growth & development , Arabidopsis/metabolism , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Molecular Sequence Data , Mutation , Plant Roots/drug effects , Plant Roots/growth & development , Sequence Homology, Amino Acid , Tryptophan/pharmacology
17.
J Bacteriol ; 177(23): 6745-50, 1995 Dec.
Article in English | MEDLINE | ID: mdl-7592463

ABSTRACT

The coding sequence of the Haemophilus influenzae ORF I gene was amplified by PCR and cloned into different Escherichia coli expression vectors. The ORF I-encoded protein was approximately 90 kDa and bound 3H-benzyl-penicillin and 125I-cephradine. This high-molecular-weight penicillin-binding protein (PBP) was also shown to possess transglycosylase activity, indicating that the ORF I product is a bifunctional PBP. The ORF I protein was capable of maintaining the viability of E. coli delta ponA ponB::spcr cells in transcomplementation experiments, establishing the functional relevance of the significant amino acid homology seen between E. coli PBP 1A and 1B and the H. influenzae ORF I product. In addition, the physiological functioning of the H. influenzae ORF I (PBP 1A) product in a heterologous species established the ability of the enzyme not only to recognize the E. coli substrate but also to interact with heterologous cell division proteins. The affinity of the ORF I product for 3H-benzylpenicillin and 125I-cephradine, the MIC of beta-lactams for E. coli delta ponA ponB::spcr expressing the ORF I gene, and the amino acid alignment of the PBP 1 family of high-molecular-weight PBPs group the ORF I protein into the PBP 1A family of high-molecular-weight PBPs.


Subject(s)
Bacterial Proteins , Carrier Proteins/genetics , Genes, Bacterial , Haemophilus influenzae/genetics , Hexosyltransferases/genetics , Multienzyme Complexes/genetics , Muramoylpentapeptide Carboxypeptidase/genetics , Peptidyl Transferases/genetics , Base Sequence , Carrier Proteins/biosynthesis , Cephalosporins/metabolism , Cephradine/metabolism , Cloning, Molecular , Escherichia coli/genetics , Genetic Complementation Test , Hexosyltransferases/biosynthesis , Microbial Sensitivity Tests , Molecular Sequence Data , Multienzyme Complexes/biosynthesis , Muramoylpentapeptide Carboxypeptidase/biosynthesis , Open Reading Frames , Penicillin-Binding Proteins , Peptidoglycan/biosynthesis , Peptidyl Transferases/biosynthesis , Polymerase Chain Reaction , Sequence Homology, Amino Acid , Species Specificity
18.
Drug Metab Dispos ; 22(2): 211-5, 1994.
Article in English | MEDLINE | ID: mdl-8013276

ABSTRACT

The disposition of the antipsoriatic agent, acitretin, was investigated in six healthy human volunteers who each received a single, oral 50 mg dose of [14C]acitretin (50 microCi). plasma, urine, and feces were collected for 240 hr after administration. Mean values of 20.9 and 62.6% of the administered dose were recovered in the urine and feces, respectively. The terminal elimination half-life of total radioactivity from the plasma was approximately 120 hr. Extraction of pooled plasma samples followed by separation by HPLC and quantitation by liquid scintillation counting indicated that acitretin and its 13-cis-isomer, isoacitretin, were minor fractions of the total drug-related material in the plasma at most time points up to 72-hr postdose. The structures of acitretin, isoacitretin, and two other metabolites--(5E,7E)-8-(4-methoxy,2,3,6-trimethylphenyl)-2,6 -dimethyl-5,7- octadienoic acid (I) and (5E,7E)-8-(4-hydroxy-2,3,6-trimethylphenyl)-2,6-dimethyl-5,7 -octadienoic acid (II)--were confirmed by MS and cochromatography with authentic standards. I and II were major fractions of the drug-related material in the plasma at all time points. Other compounds, whose structures could not be confirmed, also account for a significant fraction of the circulating radioactivity.


Subject(s)
Acitretin/pharmacokinetics , Acitretin/blood , Acitretin/urine , Administration, Oral , Chromatography, High Pressure Liquid , Chromatography, Liquid , Feces/chemistry , Glucuronidase/chemistry , Half-Life , Humans , Isomerism , Male , Mass Spectrometry , Multienzyme Complexes/chemistry , Sodium Hydroxide , Sulfatases/chemistry
19.
Xenobiotica ; 23(4): 383-90, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8337896

ABSTRACT

1. 14C-labelled 1-aminobenzotriazole (ABT), a suicide inactivator of cytochrome P450, was synthesized and administered orally to male rats. The rats were killed at 1, 6, 24, 48 or 72 h after dosing and the concentration of total radioactivity in various tissues and organs measured. 2. The compound appears to be absorbed slowly with 50% of the radioactivity remaining in the stomach at 6 h after dosing and maximum plasma and tissue concentrations were observed at 24 h. 3. Approximately 71% of the dose of 14C was excreted in the urine and 12% in the faeces over 72 h, indicating oral absorption of at least 71%. Tissue-to-plasma ratios of 14C were highest in the liver, adrenals and kidneys, which all contain significant amounts of cytochrome P450; the half-lives of elimination for total 14C in liver, adrenals and kidneys were approximately 24, 16 and 12 h, respectively, while the half-life in plasma was approximately 9 h. 4. ABT was metabolized by N-acetylation, with the acetylated product attaining concentrations equal to ABT in the plasma; two other major metabolites were also excreted in the urine namely, the N-glucuronide of 1-aminobenzotriazole and the N-glucuronide of benzotriazole.


Subject(s)
Triazoles/pharmacokinetics , Administration, Oral , Animals , Biotransformation , Chromatography, High Pressure Liquid , Half-Life , Male , Rats , Tissue Distribution , Triazoles/administration & dosage
20.
FEMS Microbiol Lett ; 106(2): 171-5, 1993 Jan 15.
Article in English | MEDLINE | ID: mdl-8454182

ABSTRACT

An internal fragment from each of the penicillin-binding protein (PBP) 1A, 2B and 2X genes of Streptococcus pneumoniae, which included the region encoding the active-site serine residue, was replaced by a fragment encoding spectinomycin resistance. The resulting constructs were tested for their ability to transform S. pneumoniae strain R6 to spectinomycin resistance. Spectinomycin-resistant transformants could not be obtained using either the inactivated PBP 2X or 2B genes, suggesting that deletion of either of these genes was a lethal event, but they were readily obtained using the inactivated PBP 1A gene. Analysis using the polymerase chain reaction confirmed that the latter transformants had replaced their chromosomal copy of the PBP 1A gene with the inactivated copy of the gene. Deletion of the PBP 1A gene was therefore tolerated under laboratory conditions and appeared to have little effect on growth or susceptibility to benzylpenicillin.


Subject(s)
Bacterial Proteins , Carrier Proteins/genetics , Gene Deletion , Genes, Bacterial , Hexosyltransferases , Muramoylpentapeptide Carboxypeptidase/genetics , Peptidyl Transferases , Streptococcus pneumoniae/genetics , Cefotaxime/pharmacology , Penicillin-Binding Proteins , Plasmids
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