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Abstract
Six luminous bacteria were isolated from migrating salmon in the Yukon River, Alaska. All isolates were identified as Photobacterium phosphoreum. Previous studies suggest that P. phosphoreum is an exclusively marine bacterium, while our Alaskan isolates are from salmon which migrated up to 1,228 km from the marine environment.
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Affiliation(s)
- K J Budsberg
- Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA
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2
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Fode-Vaughan KA, Wimpee CF, Remsen CC, Collins ML. Detection of bacteria in environmental samples by direct PCR without DNA extraction. Biotechniques 2001; 31:598, 600, 602-4, passim. [PMID: 11570503 DOI: 10.2144/01313rr04] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cultured cells and environmental samples were used directly in PCRs without the isolation of DNA. Serial dilution was used to eliminate the inhibitory effect of materials in natural samples. Primers specific for pmoA, which encodes a subunit of the particulate methane monooxygenase, were used to detect and quantify methanotrophic bacteria by direct most probable number PCR. Phototrophic bacteria were detected in environmental samples by direct PCR with primers specific for pufM, and members of the bacterial domain were detected with primers for 16S rDNA. Direct PCR provides a rapid, simple, and sensitive methodfor detecting and quantifying bacteria in environmental samples. Detection of methanotrophic bacteria can be applied to monitoring bioremediation.
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3
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Dasmahapatra AK, Wimpee BA, Trewin AL, Wimpee CF, Ghorai JK, Hutz RJ. Demonstration of 2,3,7,8-tetrachlorodibenzo-p-dioxin attenuation of P450 steroidogenic enzyme mRNAs in rat granulosa cell in vitro by competitive reverse transcriptase-polymerase chain reaction assay. Mol Cell Endocrinol 2000; 164:5-18. [PMID: 11026553 DOI: 10.1016/s0303-7207(00)00245-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in prepubertal (PP) and adult (A) rat granulosa cells (GC) in vitro by examining the changes in estrogen secretion, aromatase enzyme activity and mRNAs for steroidogenic enzymes P450scc, 3beta-HSDI, P450arom; and for components of the AHR signaling pathway-CYP1A1, aromatic hydrocarbon receptor (AHR), and the AHR nuclear translocator protein (ARNT). In PP and A rat GC, TCDD (3.1 nM) reduced estrogen secretion at 48 h without altering aromatase enzyme activity. Addition of FSH (50 ng/ml) increased aromatase activity in GC with or without TCDD. FSH-induced aromatase activity was significantly reduced by TCDD (3.1 nM) at 48 h. Semi-quantitative RT-PCR showed a significant increase in CYP1A1 mRNA both at 24 and 48 h with TCAP, while a significant reduction in P450scc and P450arom mRNA was observed with competitive RT-PCR. All steroidogenic enzyme mRNAs were significantly lower in adults than in PP GC. We conclude that in rat GC, TCDD modulates the level of cytochrome P450 enzymes involved in the steroid biosynthetic cascade. This effect may be attributable to AHR interaction with dioxin-responsive elements present in the genes encoding these enzymes.
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Affiliation(s)
- A K Dasmahapatra
- Department of Biological Sciences, University of Wisconsin-Milwaukee, 53211, USA
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4
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Makemson JC, Fulayfil NR, Landry W, Van Ert LM, Wimpee CF, Widder EA, Case JF. Shewanella woodyi sp. nov., an exclusively respiratory luminous bacterium isolated from the Alboran Sea. Int J Syst Bacteriol 1997; 47:1034-9. [PMID: 9336902 DOI: 10.1099/00207713-47-4-1034] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Thirty-four strains of nonfermentative, respiratory, luminous bacteria were isolated from samples of squid ink and seawater from depths of 200 to 300 m in the Alboran Sea. Although these strains had a few properties similar to properties of Shewanella (Alteromonas) hanedai, they did not cluster phenotypically with any previously described bacterium. The nucleotide sequence of a 740-bp segment of luxA was not homologous with other known luxA sequences but clustered with the luxA sequences of Shewanella hanedai, Vibrio logei, Vibrio fischeri, and Photobacterium species. The 16S RNA gene from two strains was sequenced and was found to be most closely related to the S. hanedai 16S RNA gene. Based on the differences observed, we describe the new isolates as members of new species, Shewanella woodyi sp. nov. Strain ATCC 51908 (= MS32) is the type strain of this new species.
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Affiliation(s)
- J C Makemson
- Department of Biological Sciences, Florida International University, Miami 33199, USA.
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5
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Les DH, Garvin DK, Wimpee CF. Phylogenetic studies in the monocot subclass Alismatidae: evidence for a reappraisal of the aquatic order Najadales. Mol Phylogenet Evol 1993; 2:304-14. [PMID: 8049779 DOI: 10.1006/mpev.1993.1029] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Within the angiosperm subclass Alismatidae (= superorder Alismatiflorae), contemporary taxonomists have often assigned the families Hydrocharitaceae and Najadaceae to different orders. The Najadaceae are presumably allied to a variety of aquatic families in the order Najadales, whereas the Hydrocharitaceae have been segregated as the order Hydrocharitales or placed within the order Alismatales. Analysis of DNA sequence data from the chloroplast gene rbcL, however, indicate that Najadaceae have a much closer phylogenetic relationship to Hydrocharitaceae than to families of the "Najadales" (Cymodoceaceae, Potamogetonaceae, Ruppiaceae, Scheuchzeriaceae, Zannichelliaceae, Zosteraceae). This association supports previous studies based upon examination of floral structure and seed coat anatomy. The rbcL sequence data also indicate that the Zosteraceae and Potamogetonaceae are closely related families. The rbcL sequence of Zostera is actually more similar to that of Potamogeton richardsonii than is the sequence of the latter to a congener, Potamogeton amplifolius. The marine, dioecious, hydrophilous genus Zostera has acquired a number of distinctive adaptations, but probably diverged relatively rapidly from freshwater Potamogetonaceae. Molecular data place Ruppiaceae as a sister group to the marine Cymodoceaceae and do not support the commonly accepted merger of Ruppiaceae and Potamogetonaceae.
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Affiliation(s)
- D H Les
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs 06269-3042
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6
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Abstract
The plastid 16S-23S intergenic spacer region in Conopholis americana, a totally heterotrophic angiosperm in the family Orobanchaceae, has undergone large deletions, including the entire tRNA(Ile) gene and all but small remnants of the tRNA(Ala) gene. The length of the region is less than 20% of that of other land plants which have been investigated, making it the smallest 16S-23S intergenic spacer reported thus far for any land plant. The remaining sequences in the spacer are 90.1% identical to tobacco, indicating that, while the region is well conserved at the sequence level, it is evolving rapidly by deletion. Experiments using the polymerase chain reaction and hybridization to DNA gel blots have failed to reveal either of the two missing tRNA genes elsewhere in the Conopholis cell.
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Affiliation(s)
- C F Wimpee
- Department of Biological Sciences, University of Wisconsin, Milwaukee 53201
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7
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Abstract
Aquatic plants are notoriously difficult to study systematically due to convergent evolution and reductionary processes that result in confusing arrays of morphological features. Plant systematists have frequently focused their attention on the "water lilies," putative descendants of the most archaic angiosperms. Classification of these 10 plant genera varies from recognition of one to three orders containing three to six families. We have used DNA sequence analysis as a means of overcoming many problems inherent in morphologically based studies of the group. Phylogenetic analyses of sequence data obtained from a 1.2-kilobase portion of the chloroplast gene rbcL provide compelling evidence for the recognition of three distinct lineages of "water lily" plants. Molecular phylogenies including woody Magnoliidae sequences and sequences of these aquatic plants depict Ceratophyllum as an early diverging genus. Our results support hypotheses that most taxonomic concepts of the order Nymphaeales reflect polyphyletic groups and that the unusual genus Ceratophyllum represents descendants of some of the earliest angiosperms.
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Affiliation(s)
- D H Les
- Department of Biological Sciences, University of Wisconsin, Milwaukee 53201
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8
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Abstract
We have used heterologous probes to investigate the degree of sequence conservation in the plastid genome of Conopholis americana, a totally achlorophyllous angiosperm which exists as a root parasite on red oaks. Although Conopholis is completely nonphotosynthetic, it retains a plastid genome in which certain regions, including that which contains the ribosomal RNA genes, are highly conserved. Other regions, including those containing the genes for numerous photosynthesis proteins, are either absent or highly divergent. We also find that the 16S and 23S ribosomal genes of the Conopholis plastid are transcribed and processed, implying a potentially functional genetic apparatus. These results are in agreement with findings reported recently for a related root parasite, Epifagus virginiana (dePamphilis and Palmer, 1990). Furthermore, the plastid genome is maintained in high copy number in fruit tissue, whereas mature seeds have an approximately 10-fold lower copy number.
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Affiliation(s)
- C F Wimpee
- Department of Biological Sciences, University of Wisconsin-Milwaukee 53201
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Wimpee CF, Nadeau TL, Nealson KH. Development of species-specific hybridization probes for marine luminous bacteria by using in vitro DNA amplification. Appl Environ Microbiol 1991; 57:1319-24. [PMID: 1854194 PMCID: PMC182949 DOI: 10.1128/aem.57.5.1319-1324.1991] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
By using two highly conserved region of the luxA gene as primers, polymerase chain reaction amplification methods were used to prepare species-specific probes against the luciferase gene from four major groups of marine luminous bacteria. Laboratory studies with test strains indicated that three of the four probes cross-reacted with themselves and with one or more of the other species at low stringencies but were specific for members of their own species at high stringencies. The fourth probe, generated from Vibrio harveyi DNA, cross-reacted with DNAs from two closely related species, V. orientalis and V. vulnificus. When nonluminous cultures were tested with the species-specific probes, no false-positive results were observed, even at low stringencies. Two field isolates were correctly identified as Photobacterium phosphoreum by using the species-specific hybridization probes at high stringency. A mixed probe (four different hybridization probes) used at low stringency gave positive results with all of the luminous bacteria tested, including the terrestrial species, Xenorhabdus luminescens, and the taxonomically distinct marine bacterial species Shewanella hanedai; minimal cross-hybridization with these species was seen at higher stringencies.
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Affiliation(s)
- C F Wimpee
- Department of Biological Sciences, University of Wisconsin--Milwaukee 53201
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Wimpee CF, Tobin EM. Cloning and expression of genes for the small subunit of ribulosebisphosphate carboxylase. Methods Enzymol 1986; 118:396-409. [PMID: 2419736 DOI: 10.1016/0076-6879(86)18088-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Stiekema WJ, Wimpee CF, Tobin EM. Nucleotide sequence encoding the precursor of the small subunit of ribulose 1,5-bisphosphate carboxylase from Lemna gibba L.G-3. Nucleic Acids Res 1983; 11:8051-61. [PMID: 6316282 PMCID: PMC326559 DOI: 10.1093/nar/11.22.8051] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We have sequenced a cDNA clone, pLgSSU, which encodes the small subunit of ribulose 1,5-bisphosphate carboxylase of Lemna gibba L.G-3 a monocot plant. This clone contains a 832 basepair insert which encodes the entire 120 amino acids of the mature small subunit polypeptide (Mr = 14,127). In addition this clone encodes 53 amino acids of the amino terminal transit peptide of the precursor polypeptide and 242 nucleotides of the 3' non-coding region. Comparison of the nucleotide sequence of pLgSSU with Lemna gibba genomic sequences homologous to the 5' end of the cDNA clone suggests that nucleotides encoding four amino-terminal amino acids of the transit peptide are not included in the cDNA clone. The deduced amino acid sequence of the Lemna gibba mature small subunit polypeptide shows 70-75% homology to the reported sequences of other species. The transit peptide amino acid sequence shows less homology to other species. There is 50% homology to the reported soybean sequence and only 25% homology to the transit sequence of another monocot, wheat.
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Stiekema WJ, Wimpee CF, Silverthorne J, Tobin EM. Phytochrome Control of the Expression of Two Nuclear Genes Encoding Chloroplast Proteins in Lemna gibba L. G-3. Plant Physiol 1983; 72:717-24. [PMID: 16663073 PMCID: PMC1066308 DOI: 10.1104/pp.72.3.717] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Hybridization probes for two nuclear-coded chloroplast proteins of Lemna gibba L. G-3 have been constructed in order to investigate phytochrome regulation of specific sequences. The first probe is a cDNA clone encoding the small subunit of ribulose 1,5-bisphosphate carboxylase. This probe was isolated from a set of Lemna cDNA clones in the bacterial plasmid pBR322. The second probe is a subclone of a genomic clone encoding the light-harvesting chlorophyll a/b-protein. This clone was isolated from a set of genomic clones constructed in the lambda vector Charon 4 with L. gibba DNA fragments generated by partial EcoR1 digestion. The identity of these clones was confirmed by in vitro translation of RNA which hybridized to the cloned DNA. Plants grown under continuous white light contain high concentrations of both RNA sequences; however, when these plants are put into darkness the concentration of these RNAs decreases rapidly relative to the total amount of RNA. Plants grown in the dark with intermittent red light (2 minutes/8 hours) and put into complete darkness for 8 days also contain lower concentrations of the sequences in the total RNA. One minute of red light after this dark period results in a rapid increase in the levels of RNA hybridizing to the probes. The effect of red light can be reversed by far-red light. These experiments demonstrate that phytochrome action can rapidly influence either the rates of transcription or the rates of degradation of these mRNAs.
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Affiliation(s)
- W J Stiekema
- Department of Biology and Molecular Biology Institute, University of California, Los Angeles, California 90024
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13
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Abstract
The nuclear genome of pearl millet has been characterized with respect to its size, buoyant density in CsCl equilibrium density gradients, melting temperature, reassociation kinetics and sequence organization. The genome size is 0.22 pg. The mol percent G + C of the DNA is calculated from the buoyant density and the melting temperature to be 44.9 and 49.7%, respectively. The reassociation kinetics of fragments of DNA 300 nucleotides long reveals three components: a rapidly renaturing fraction composed of highly repeated and/or foldback DNA, middle repetitive DNA and single copy DNA. The single copy DNA consists of 17% of the genome. 80% of the repetitive sequences are at least 5000 nucleotide pairs in length. Thermal denaturation profiles of the repetitive DNA sequences show high Tm values implying a high degree of sequence homogeneity. About half of the single copy DNA is short (750--1400 nucleotide paris) and interspersed with long repetitive DNA sequences. The remainder of the single copy sequences vary in size from 1400 to 8600 nucleotide pairs.
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