Showing papers on "Gene published in 1982"
TL;DR: A series of recombinant genomes which directed expression of the enzyme chloramphenicol acetyltransferase (CAT) in mammalian cells provided a uniquely convenient system for monitoring the expression of foreign DNAs in tissue culture cells.
Abstract: We constructed a series of recombinant genomes which directed expression of the enzyme chloramphenicol acetyltransferase (CAT) in mammalian cells. The prototype recombinant in this series, pSV2-cat, consisted of the beta-lactamase gene and origin of replication from pBR322 coupled to a simian virus 40 (SV40) early transcription region into which CAT coding sequences were inserted. Readily measured levels of CAT accumulated within 48 h after the introduction of pSV2-cat DNA into African green monkey kidney CV-1 cells. Because endogenous CAT activity is not present in CV-1 or other mammalian cells, and because rapid, sensitive assays for CAT activity are available, these recombinants provided a uniquely convenient system for monitoring the expression of foreign DNAs in tissue culture cells. To demonstrate the usefulness of this system, we constructed derivatives of pSV2-cat from which part or all of the SV40 promoter region was removed. Deletion of one copy of the 72-base-pair repeat sequence in the SV40 promoter caused no significant decrease in CAT synthesis in monkey kidney CV-1 cells; however, an additional deletion of 50 base pairs from the second copy of the repeats reduced CAT synthesis to 11% of its level in the wild type. We also constructed a recombinant, pSV0-cat, in which the entire SV40 promoter region was removed and a unique HindIII site was substituted for the insertion of other promoter sequences.
7,438 citations
TL;DR: A rosy transposon (ry1), constructed by inserting a chromosomal DNA fragment containing the wild-type rosy gene into a P transposable element, transformed germ line cells in 20 to 50 percent of the injected rosy mutant embryos indicating that the visible genetic defect in the host strain could be fully and permanently corrected by the transferred gene.
Abstract: Exogenous DNA sequences were introduced into the Drosophila germ line. A rosy transposon (ry1), constructed by inserting a chromosomal DNA fragment containing the wild-type rosy gene into a P transposable element, transformed germ line cells in 20 to 50 percent of the injected rosy mutant embryos. Transformants contained one or two copies of chromosomally integrated, intact ry1 that were stably inherited in subsequent generations. These transformed flies had wild-type eye color indicating that the visible genetic defect in the host strain could be fully and permanently corrected by the transferred gene. To demonstrate the generality of this approach, a DNA segment that does not confer a recognizable phenotype on recipients was also transferred into germ line chromosomes.
3,004 citations
Journal Article•
TL;DR: A bacterial gene conferring resistance to neomycin-kanamycin antibiotics has been inserted into SV40 hybrid plasmid vectors and introduced into cultured mammalian cells by DNA transfusion and it is shown that cell transformation to G418 resistance is an efficient means for cotransformation of nonselected genes.
Abstract: A bacterial gene (neo) conferring resistance to neomycin-kanamycin antibiotics has been inserted into SV40 hybrid plasmid vectors and introduced into cultured mammalian cells by DNA transfusion. Whereas normal cells are killed by the antibiotic G418, those that acquire and express neo continue to grow in the presence of G418. In the course of the selection, neo DNA becomes associated with high molecular weight cellular DNA and is retained even when cells are grown in the absence of G418 for extended periods. Since neo provides a marker for dominant selections, cell transformation to G418 resistance is an efficient means for cotransformation of nonselected genes.
2,555 citations
TL;DR: It is proposed that tumorigenesis by MMTV is strongly favored by proviral insertion within the int1 locus, perhaps as a consequence of enhanced expression of a novel cellular oncogene.
1,781 citations
TL;DR: Extreme codon bias is seen for the Saccharomyces cerevisiae genes for the fermentative alcohol dehydrogenase isozyme I (ADH-I) and glyceraldehyde-3-phosphate dehydrogenased genes and a similar phenomenon is observed in the codon preferences of highly expressed genes in Escherichia coli.
1,490 citations
25 Apr 1982
TL;DR: The bovine 12 S and 16 S Ribosomal RNA genes, when compared with those from human mitochondrial DNA, show conserved features that are consistent with proposed secondary structure models for the ribosomal RNAs.
Abstract: We present here the complete 16,338 nucleotide DNA sequence of the bovine mitochondrial genome. This sequence is homologous to that of the human mitochondrial genome (Anderson et al., 1981) and the genes are organized in virtually identical fashion. The bovine mitochondrial protein genes are 63 to 79% homologous to their human counterparts, and most of the nucleotide differences occur in the third positions of codons. The minimum rate of base substitution that accounts for the nucleotide differences in the codon third positions is very high: at least 6 × 10−9 changes per position per year. The bovine and human mitochondrial transfer RNA genes exhibit more interspecies variation than do their cytoplasmic counterparts, with the “TΨC” loop being the most variable part of the molecule. The bovine 12 S and 16 S ribosomal RNA genes, when compared with those from human mitochondrial DNA, show conserved features that are consistent with proposed secondary structure models for the ribosomal RNAs. Unlike the pattern of moderate-to-high homology between the bovine and human mitochondrial DNAs found over most of the genome, the DNA sequence in the bovine D-loop region is only slightly homologous to the corresponding region in the human mitochondrial genome. This region is also quite variable in length, and accounts for the bulk of the size difference between the human and bovine mitochondrial DNAs.
1,407 citations
TL;DR: RNA viruses show high mutation frequencies partly because of a lack of the proofreading enzymes that assure fidelity of DNA replication, and high rates of replication reflected in rates of RNA genome evolution which can be more than a millionfold greater than the rates of the DNA chromosome evolution of their hosts.
Abstract: RNA viruses show high mutation frequencies partly because of a lack of the proofreading enzymes that assure fidelity of DNA replication. This high mutation frequency is coupled with high rates of replication reflected in rates of RNA genome evolution which can be more than a millionfold greater than the rates of the DNA chromosome evolution of their hosts. There are some disease implications for the DNA-based biosphere of this rapidly evolving RNA biosphere.
1,394 citations
TL;DR: Positive hybridization is found when the 22q−(the Philadelphia chromosome), and not the 9q+ derivative of the translocation, is present in the cell hybrids, and this finding is a direct demonstration of a reciprocal exchange between the two chromosomes and suggests a role for the c-abl gene in the generation of CML.
Abstract: The transforming genes of oncogenic retroviruses are homologous to a group of evolutionary conserved cellular onc genes. The human cellular homologue (c-abl) of the transforming sequence of Abelson murine leukaemia virus (A-MuL V) was recently shown to be located on chromosome 9. The long arm of this chromosome is involved in a specific translocation with chromosome 22, the Philadelphia translocation (Ph1), t(9; 22) (q34, q11), which occurs in patients with chronic myelocytic leukaemia (CML)3-5. Here we investigate whether the c-abl gene is included in this translocation. Using c-abl and v-abl hybridization probes on blots of somatic cell hybrids, positive hybridization is found when the 22q- (the Philadelphia chromosome), and not the 9q+ derivative of the translocation, is present in the cell hybrids. From this we conclude that in CML, c-abl sequences are translocated from chromosome 9 to chromosome 22q-. This finding is a direct demonstration of a reciprocal exchange between the two chromosomes and suggests a role for the c-abl gene in the generation of CML.
1,329 citations
TL;DR: It is shown that transformation of human Burkitt lymphomas and murine plasmacytomas is frequently accompanied by the somatic rearrangement of a cellular analogue of an avian retrovirus transforming gene, c-myc, which provides a molecular basis for considering the role that specific translocations might play in malignant transformation.
Abstract: The consistent appearance of specific chromosomal translocations in human Burkitt lymphomas and murine plasmacytomas has suggested that these translocations might play a role in malignant transformation. Here we show that transformation of these cells is frequently accompanied by the somatic rearrangement of a cellular analogue of an avian retrovirus transforming gene, c-myc. Moreover, we map c-myc to human chromosome 8 band q24, the chromosomal segment involved in the reciprocal Burkitt translocations [t(8;14), t(8;22) and t(2;8)]. In two t(8;14) human Burkitt cell lines, c-myc appears to have been translocated directly into a DNA restriction fragment that also encodes the immunoglobulin mu chain gene. In the case of a specific cloned fragment of DNA derived from a mouse plasmacytoma, we demonstrate directly that c-myc has been translocated into the immunoglobulin alpha switch region. Our data provide a molecular basis for considering the role that specific translocations might play in malignant transformation.
1,324 citations
TL;DR: A DNA fragment containing the promoter of the mouse metallothionein-I gene fused to the structural gene of rat growth hormone was microinjected into the pronuclei of fertilized mouse eggs, and seven mice developed that carried the fusion gene and six of these grew significantly larger than their littermates.
Abstract: A DNA fragment containing the promoter of the mouse metallothionein-I gene fused to the structural gene of rat growth hormone was microinjected into the pronuclei of fertilized mouse eggs. Of 21 mice that developed from these eggs, seven carried the fusion gene and six of these grew significantly larger than their littermates. Several of these transgenic mice had extraordinarily high levels of the fusion mRNA in their liver and growth hormone in their serum. This approach has implications for studying the biological effects of growth hormone, as a way to accelerate animal growth, as a model for gigantism, as a means of correcting genetic disease, and as a method of farming valuable gene products.
1,306 citations
TL;DR: A model is proposed to account for the synthesis and regulation of the two forms of inverts: the larger, regulated mRNA contains the initiation codon for the signal sequence required for synthesis of the secreted, glycosylated form of invertase; the smaller, constitutively transcribed mRNA begins within the coding region of the signal sequences, resulting in synthesis ofThe intracellular enzyme.
TL;DR: Transcriptional control signals of a model eukaryotic protein-coding gene have been identified by a new procedure of in vitro mutagenesis that allows small clusters of nucleotide residues to be substituted in a site-directed manner without causing the addition or deletion of other sequences.
Abstract: Transcriptional control signals of a model eukaryotic protein-coding gene have been identified by a new procedure of in vitro mutagenesis. This method allows small clusters of nucleotide residues to be substituted in a site-directed manner without causing the addition or deletion of other sequences. Transcription assays of a systematic series of these clustered point mutants have led to the identification of three distinct control signals located within the 105-nucleotide residues immediately upstream from the point where transcription begins.
TL;DR: The distribution of other rare codons in the genes of the left arm suggests that they may have a controlling function on the relative amounts of the proteins produced, and the genome is fairly compact with comparatively little non-coding DNA.
Book•
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01 Jan 1982
TL;DR: This book contains 12 selections of retroviral diseases and some of the titles are: Genome Structure;Genetics of Retroviruses;Functions and Origins of Retoviral Transforming Genes;Human T-cell RetrovIRuses;Replications of Retrospective Viruses; and Endogenous Viruses.
Abstract: This book contains 12 selections Some of the titles are: Genome Structure;Genetics of Retroviruses;Functions and Origins of Retroviral Transforming Genes;Human T-cell Retroviruses;Replications of Retroviruses;and Endogenous Viruses
TL;DR: The nucleotide sequence of 1200 bp from the unique region of transposon Tn5 containing the neomycin phosphotransferase gene (neo) was determined, and the location of the neo gene was identified by deletion mutants in a translational reading frame of 792 bp.
TL;DR: It seems that the upstream element of the hsp 70 promoter is analogous to that of other promoters, but is only functional in heat-shocked cells.
TL;DR: Examination of homologies between retroviral oncogenes and transforming sequences defined by transfection reveals that the human bladder carcinoma (EJ) oncogene is homologous to the Harvey sarcoma virus onCogene (ras).
Abstract: Examination of homologies between retroviral oncogenes and transforming sequences defined by transfection reveals that the human bladder carcinoma (EJ) oncogene is homologous to the Harvey sarcoma virus oncogene (ras). Structural analysis limits the region of homology to a 3.0-kilobase SacI fragment of the EJ oncogene. Both EJ and ras DNA probes detect similar transcripts in transfectants derived from bladder carcinoma cell lines.
TL;DR: A consensus sequence is uncovered between the region deleted in cyc1-512 and the 3' nontranslated regions of some but not all yeast genes, and the possible role of this sequence in transcription termination is discussed.
TL;DR: Together analysis of DNA polymorphisms in the human β-globin gene cluster and in cloned β-genes has revealed the association of specific β-thalassaemia mutations and β-gene polymorphisms with particular flanking polymorphisms.
Abstract: Combined analysis of DNA polymorphisms in the human β-globin gene cluster and in cloned β-genes has revealed the association of specific β-thalassaemia mutations and β-gene polymorphisms with particular flanking polymorphisms. A systematic study of cloned genes identified several new mutations, one of which possibly affects transcription. The strategy used may be applicable to other diseases of single-copy genes.
TL;DR: 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.
Abstract: 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.
TL;DR: These studies demonstrate the use ofvaccinia virus as a selectable cloning and expression vector, confirm the map location of the vaccinia virus TK gene, and provide initial information regarding the location of vacciniairus transcriptional regulatory sequences.
Abstract: Foreign DNA was inserted into two nonessential regions of the vaccinia virus genome by homologous recombination in cells infected with virus and transfected with plasmids containing the foreign DNA elements flanked by vaccinia virus DNA. Thymidine kinase-negative (TK-) recombinants were selected after inserting foreign DNA into the coding region of the TK gene of wild-type vaccinia virus; TK+ recombinants were selected after inserting the herpesvirus TK gene into TK- mutants of vaccinia virus. For TK+ expression, it was necessary to insert a 275-base-pair DNA fragment containing the initiation site and sequences upstream of an early vaccinia virus transcript next to the coding sequences of the herpesvirus gene. The unique ability of the herpesvirus TK to phosphorylate 125I-labeled deoxycytidine provided independent confirmation of gene expression. These studies demonstrate the use of vaccinia virus as a selectable cloning and expression vector, confirm the map location of the vaccinia virus TK gene, and provide initial information regarding the location of vaccinia virus transcriptional regulatory sequences.
TL;DR: Results indicate that the transforming genes of these human tumor cell lines are the cellular homologs of two retroviral transforming genes.
Abstract: Blot hybridization analysis indicated that NIH 3T3 mouse bladder transformed by high molecular weight DNAs of a human bladder and a human lung carcinoma cell line contained new sequences homologous, respectively, to the transforming genes of Harvey (rasH) and Kirsten (rasK) sarcoma viruses. The unique ras sequences were present in multiple independent NIH cell lines transformed in both primary and secondary transfection assays and corresponded to ras sequences normally present in human DNAs. The ras gene product was expressed in NIH cells transformed by bladder carcinoma DNAs and in the human bladder carcinoma cell lines at levels 2- to 4-fold greater than the level observed in nontransformed NIH 3T3 cells. These results indicate that the transforming genes of these human tumor cell lines are the cellular homologs of two retroviral transforming genes.
TL;DR: The H-ras-1 gene cloned from T24 DNA induces transformation in NIH 3T3 cells, while the same gene cloning from normal cellular DNA does not, and the functionally significant difference appears to be a single base mutation.
Abstract: Several different transforming genes have been observed in the DNA of a variety of tumours and tumour cell lines of human and rodent origin by the ability of these genes to induce morphological transformation in NIH 3T3 cells1-5. The transforming gene found in a human bladder carcinoma cell line, T24, is H-ras-1, the human homologue of the Harvey sarcoma virus oncogene (v-H-ras)6-9. In the present study we have compared the H-ras-1 genes cloned from T24 and normal human DNA. The H-ras-1 gene cloned from T24 DNA induces transformation in NIH 3T3 cells, while the same gene cloned from normal cellular DNA does not. The functionally significant difference between the transforming and normal genes appears to be a single base mutation, which produces an amino acid change in the sequence of the proteins that the genes encode.
TL;DR: The Shine and Dalgarno sequence of 124 known gene beginnings is characterized and this information is used to make "rules" which help distinguish gene beginning from other sites in a library of over 78,000 bases of mRNA.
Abstract: We characterize the Shine and Dalgarno sequence of 124 known gene beginnings. This information is used to make "rules" which help distinguish gene beginning from other sites in a library of over 78,000 bases of mRNA. Gene beginnings are found to have information besides the initiation codon and Shine and Dalgarno sequence which can be used to make better "rules".
TL;DR: Oligonucleotide primers have been used to generate a cDNA library covering the entire tobacco mosaic virus (TMV) RNA sequence and analysis of these clones has enabled us to complete the viralRNA sequence and to study its variability within a viral population.
Abstract: Oligonucleotide primers have been used to generate a cDNA library covering the entire tobacco mosaic virus (TMV) RNA sequence. Analysis of these clones has enabled us to complete the viral RNA sequence and to study its variability within a viral population. The positive strand coding sequence starts 69 nucleotides from the 5' end with a reading frame for a protein of Mr 125,941 and terminates with UAG. Readthrough of this terminator would give rise to a protein of Mr 183,253. Overlapping the terminal five codons of this readthrough reading frame is a second reading frame coding for a protein of Mr 29,987. This gene terminates two nucleotides before the initiator codon of the coat protein gene. Potential signal sequences responsible for the capping and synthesis of the coat protein and Mr 29,987 protein mRNAs have been identified. Similar sequences within these reading frames may be used in the expression of sets of proteins that share COOH-terminal sequences.
TL;DR: A transforming gene isolated from T24 human bladder carcinoma cells is closely related to the BALB murine sarcoma virus (MSV) onc gene (v-bas), which implies that rather subtle genetic alterations have led to the activation of the normal human homologue of v-bas as a human transforming gene.
Abstract: A transforming gene isolated from T24 human bladder carcinoma cells is closely related to the BALB murine sarcoma virus (MSV) onc gene (v-bas). This transforming gene is localized to a 4.6 kilobase pair (kbp) region and is expressed as a 1.2-kbp polyadenylated transcript, which contains v-bas related sequences. Moreover, antisera known to detect the immunologically related onc gene products of BALB- and Harvey-MSVs recognized elevated levels of a related protein in T24 cells. The normal human homologue of v-bas was found to be indistinguishable from the T24 oncogene by heteroduplex and restriction enzyme analysis. These results imply that rather subtle genetic alterations have led to the activation of the normal human homologue of v-bas as a human transforming gene.
TL;DR: Investigation of the cellular homologue, c-myc, of the transforming gene of avian myelocytomatosis virus and its role in the pathogenesis of chicken B-cell lymphomas induced by the non-acute leukosis virus finds that any structural alteration at the genomic level could account for the increased expression of c- myc in HL-60.
Abstract: Cellular onc genes are a group of evolutionarily conserved sequences which are homologous to the transforming genes (v-onc) of oncogenic retroviruses1. Their function in normal cells is not yet known, but the sequence homology between viral and cellular onc genes is consistent with the idea that neoplastic transformation may, in some cases, be due to increased levels of cellular onc gene expression. The cellular homologue, c-myc, of the transforming gene of avian myelocytomatosis virus (MC29)1,2 is involved in the pathogenesis of chicken B-cell lymphomas induced by the non-acute leukosis virus (RAV-2)3–6, and in these tumours, c-myc expression is enhanced by the nearby integration of the RAV-2 terminal repeat region3–6. Transcripts from the c-myc gene are detectable in a variety of human cells7,8, and increased levels of myc mRNA have been occasionally detected in some neoplastic tissues7,8. The highest levels have been detected in the cell line HL-60 (ref. 8) derived from neoplastic cells from a patient with acute promyelocytic leukaemia (APL)9. We have now investigated whether any structural alteration at the genomic level could account for the increased expression of c-myc in HL-60 and report here that the c-myc gene is stably amplified in HL-60 DNA. Amplification was also detected in primary uncultured leukaemic cells from the same individual, suggesting that the c-myc amplification may have been involved in the leukaemic transformation in this case.
TL;DR: The ability to isolate suitable amounts of high molecular weight DNA from peripheral blood provides a relatively simple means of constructing human gene libraries representing a variety of hemoglobin disorders.
Abstract: We describe a rapid procedure for constructing cloned human genomic libraries from small amounts of peripheral blood High molecular weight DNA is isolated from 5–20 ml peripheral blood, partially cleaved with Eco R1, and 8–22 kb fragments are cloned using bacteriophage Charon 4A and a suitable Ecoli host Using this approach we have isolated and characterized several non-a globin clones from a Kurdish Jew with homozygous β thalassemia The ability to isolate suitable amounts of high molecular weight DNA from peripheral blood provides a relatively simple means of constructing human gene libraries representing a variety of hemoglobin disorders
TL;DR: DNA's of various tumors induce transformation with high efficiencies, indicating that oncogenesis can involve dominant genetic alterations resulting in activation of cellular transforming genes.
Abstract: Cellular genes potentially capable of inducing oncogenic transformation have been identified by homology to the transforming genes of retroviruses and by the biological activity of cellular DNA's in transfection assays. DNA's of various tumors induce transformation with high efficiencies, indicating that oncogenesis can involve dominant genetic alterations resulting in activation of cellular transforming genes. The identification and characterization of cellular transforming genes and their possible involvement in naturally occurring cancers, is discussed.
TL;DR: It is demonstrated that sequences in normal human DNA homologous to the avian myc oncogene are present in multiple copies in the chromosomal DNA of the human leukaemia cell line HL-60, and this myc-related gene amplification is not present in other cultured human myeloid leukaems, including K-56214 and KG-115.
Abstract: Malignant transformation of cells by acute transforming RNA tumour viruses is mediated by the expression of certain specific pro viral DNA sequences (‘oncogenes’). These sequences have been well characterized and, in many cases, molecularly cloned1–8. These viral oncogenes are related to similar genes found in normal uninfected cells9,10. Moreover, these particular sequences are highly conserved in evolution4,11, suggesting that these genes have an important, albeit unknown, role in normal cell function. It has been suggested that an increased dosage of products of such endogenous oncogenes may be responsible for malignant transformation10,12,13. For example, increased expression of the endogenous chick c-myc oncogene has been observed in avian leukosis virus-induced transformation of chick bursal lymphocytes12. Here we demonstrate that sequences in normal human DNA homologous to the avian myc oncogene are present in multiple copies in the chromosomal DNA of the human leukaemia cell line HL-60. Other transformation-specific genes derived from the Abelson leukaemia virus4 and feline sarcoma virus6 are not amplified in HL-60. This myc-related gene amplification is not present in other cultured human myeloid leukaemia cells, including K-56214 and KG-115.