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F Gannon

Publications and source records attributed to F Gannon.

At least 109 records · Page 6Linked to original sources
PubMed1990

Electrotransfection of Escherichia coli with lambda gt10 DNA.

We have used electroporation to introduce lambda gt10 DNA into E. coli C600 (Electrotransfection). We obtained approximately 10(7) pfu (plaque forming units) per micrograms of lambda gt10 DNA. This frequency is 100-fold higher than the maximum reported for classical calcium chloride-induced transfection. We have also compared electrotransfection with in vitro packaging in cloning experiments using relatively small amounts (less than or equal to 10 ng) of DNA. Our results slow that electrotransfection can generate approximately 1000-fold more plaques than in vitro packaging at these concentrations.

Bacteriophage lambda↗
PubMed1990

A general method to generate DNA probes for microorganisms.

We present a method that permits the rapid generation of DNA probes for eubacteria. In the procedure the variable regions for the 16s rRNA genes are amplified using polymerase chain reaction (PCR) technology and primers based on the conserved regions of these genes. Following sequencing of the variable regions, a choice is possible for a probe specific for that organism. No knowledge of the molecular biology of the microorganism is required prior to the application of this approach. The generality of the method is shown using Salmonella typhimurium, Staphylococcus aureus, Clostridium perfringens, Klebsiella pneumoniae, Pseudomonas fluorescens, Aeromonas salmonicida and Mycobacterium bovis. A. salmonicida was examined in detail and a DNA probe was prepared that distinguishes it from other Aeromonas species.

Aeromonas↗
PubMed1990

Atlantic salmon (Salmo salar) serum albumin: cDNA sequence, evolution, and tissue expression.

Atlantic salmon serum albumin is one of the most abundant proteins in salmon liver, representing 1.6% of all clones in a cDNA library made from salmon liver RNA. The DNA from a number of clones was sequenced to reveal an open reading frame of 1,827 bases encoding a 608-amino-acid protein. The sequenced 5' untranslated region is 69 bases long and the 3' untranslated region contains two putative polyadenylation signals and poly(A) tail. Sequence analysis of different clones indicates the presence of a second cDNA for salmon serum albumin. Multiple alignments of salmon serum albumin deduced amino acid sequence with Xenopus laevis, rat, bovine, and human serum albumins shows significant conservation of cysteine residues. The triple domain structure of serum albumin proteins is maintained. Unlike mammalian systems where serum albumin expression appears to be specific to liver only, salmon serum albumin is expressed in muscle also.

Amino Acid Sequence↗
PubMed1989

An analysis by restriction enzymes of the genomic structure of the 3' untranslated region of the human estrogen receptor gene.

The estrogen receptor gene has a very long 3' untranslated region. As a first step towards the analysis of this structural feature for any functional role, we have cloned the human genomic estrogen receptor gene. Extensive restriction enzyme analysis of this DNA and comparison of the sizes of the DNA fragments obtained with those predicted from published cDNA sequences indicate that the 3' exon extends for at least 4304 bases from base number 2018 in the cDNA to the end of the cDNA. The data also show that the most 3' intron in this gene occurs between bases 1902 and 2018 of the cDNA.

Cloning, Molecular↗
PubMed1988

The analysis of EBV proteins which are antigenic in vivo.

We have used small random EBV B95-8 DNA fragments to generate a large genomic bank in a plasmid expression vector. This bank was screened with a pool of sera from individuals with IM thus allowing any EBV antigen which evoked an immune response in man to be identified. The characterization of four immunopositive clones obtained in this way is presented in this study. Three of these clones express viral ORF DNA sequences which are parts of larger ORFs in the BamH1 N(het), V and X regions of the B95-8 viral genome. cDNA cloning has been used to confirm that the cloned sequences from BamH1 N and V are expressed in cell culture and to identify the transcription units involved. The fourth clone expresses an ORF sequence located in the viral BamH1 F fragment in a region not previously recognized as having protein coding potential. The experimental design used here must reflect the situation in vivo and consequently these sequences must be expressed and be antigenic during IM.

Amino Acid Sequence↗
PubMed1988

The expression of novel antigens from the Epstein-Barr virus large internal repeat.

A large Epstein-Barr virus (EBV) B95-8 genomic bank has been prepared in an Escherichia coli expression vector and screened with a pool of sera from human infectious mononucleosis patients. Four immunopositive clones which also contained sequences from the viral large internal repeat were selected. DNA sequence analysis has located them on the repeat sequence and shown that they come from three potential open reading frames and that two of them consist of overlapping reading frames. This must imply extensive intron/exon splicing or that the repeat itself encodes several different proteins. The four expressed epitopes were shown to be present simultaneously in independent cases of infectious mononucleosis. These have not been previously described and based on the experimental design, they must reflect the situation in vivo.

Amino Acid Sequence↗
PubMed1987

A hybridization and enzyme blocking method to enrich minor cDNA sequences.

A method is presented which allows for the enrichment of low frequency cDNA sequences. The crucial step in the procedure is the hybridization of a pool of cDNA to homologous or heterologous RNA to a Rot value which will leave minor sequences in a single strand cDNA form while the major sequences form cDNA:RNA hybrids. This allows subsequent enzymatic differentiation between major and minor sequences resulting ultimately in the degradation of the major sequences. The procedure is general and simple as it requires no column chromatography step. The method is designed to integrate into a widely used cDNA cloning protocol and results either in double-stranded cDNA which can be used for molecular cloning or as a source of probes for hybridization.

Animals↗
PubMed1986

Plaque dot assay.

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Bacteriophage lambda↗
PubMed1982

Cloning of cDNA sequences of hormone-regulated genes from the MCF-7 human breast cancer cell line.

cDNA clones corresponding to a mRNA whose level is rapidly increased by addition of oestradiol to the culture medium have been isolated by differential screening of a cDNA library from the breast cancer cell line MCF-7, which contains oestrogen receptors. Such clones will be useful in studies of the DNA sequences required for hormonal induction and to determine whether expression of the corresponding gene is in any way related to the cancerous state. We have also obtained a cDNA clone for a messenger whose level is apparently decreased by steroid hormones.

Breast Neoplasms↗
PubMed1981

Characterization of a gene encoding a 115 K super T antigen expressed by a SV40-transformed rat cell line.

It has been reported that SV40-transformed V 11 F 1 clone 1 subclone 7 rat cells (subclone 7) produce a super T antigen of 115,000 M. This super T antigen is entirely SV40 coded and is synthesized by translation of an elongated form of SV40 early mRNA (May, E., Kress, M. Daya-Grosjean, L., Monier, R. and May, P. (1981) J. Virol., 37, 24-35). The results reported here show that there is only one independent insertion of viral DNA in the cellular genome of subclone 7 cells. When DNA from subclone 7 cells was cleaved with Bam HI endonuclease two distinct SV40 sequence containing fragments were generated with sizes of 5 Kb and 10 Kb, respectively. Two recombinant cosmids were constructed by insertion of the 5 Kb and 10 Kb fragments, respectively, into cosmid pHC 79. Using restriction map analysis and nucleotide sequencing, we showed that the 5 Kb fragment actually contained the complete sequence of a gene encoding super T antigen. As compared to the normal SV40 early gene, the sequence of super T gene showed the following rearrangements: (i) The segment between nucleotides 4116 - 3544 was duplicated in a direct order and (ii) these two copies of 573 nucleotide sequence were separated by a 93 nucleotide tract which was a nearly perfect inverted repeat of the segment located between nucleotides 4868 and 4776 (nucleotide numbering used here = Weissmann number +17).

Animals↗
PubMed1980

Cloning and characterization of DNA sequences complementary to messenger ribonucleic acids coding for the synthesis of two surface antigens of Trypanosoma brucei.

Full length double-stranded complementary DNAs (ds cDNAs) could be synthesized on mRNAs enriched in sequences coding for the synthesis of the variant specific antigens (VSAs) AnTat 1.1 and AnTat 1.8 from Trypanosoma brucei brucei. The size of these ds cDNAs is about 1700 and 1850 base pairs for AnTat 1.1 and AnTat 1.8 respectively. The ds cDNAs were cloned in the plasmid pBR322; two clones harboring a copy of each coding sequence were selected. Both the hybrid-arrested translation and the positive hybridization elution methods confirmed that these recombinants contain VSA-specific inserts. A restriction map was constructed in each case. The two sequences seem to be inserted in a reversed 3'--5' orientation, respective to the plasmid polarity. The AnTat 1.8 cloned sequence is a palindrome probably due to a cloning artefact. Hybridization of the cloned DNAs with "Northern" blots of total or poly(A)+ RNA revealed in each case a single, specific band. The expression of these VSA genes appears thus to be regulated at the transcriptional level.

Antigens, Surface↗
PubMed1980

A detailed comparison of the 5'-end of the ovalbumin gene cloned from chicken oviduct and erythrocyte DNA.

We have examined homologous fragments of DNA cloned from two different tissues for changes in the dNA sequence which might be related to tissue specific gene expression. The 5' end of the chicken ovalbumin gene was cloned from oviduct or erythrocyte DNA DNA using cosmids as vectors. We have compared the two clones obtained by restriction enzyme digestions, analysis of heteroduplexes by electron microscopy or S1 nuclease digestion and by DNA sequencing. Our results show that whereas no alteration occured in the region of the gene assumed to be of importance for the control of transcription, a 4 nucleotide deletion/insertion was detected in the first intron of the ovalbumin gene.

Animals↗