Showing papers on "Pseudogene published in 1980"
TL;DR: The somatic 5S DNAs from X. laevis and X. borealis and a minor oocyte-specific 5S DNA from Xit have been purified, and individual repeating units have been cloned and sequenced.
247 citations
TL;DR: Comparison of this sequence with a normal human α-globin gene (α2) reveals that ψα1 contains both an initiator codon mutation and frameshift deletions which would prevent the production of an α- globin polypeptide.
209 citations
TL;DR: In vivo and in vitro systems for studying the expression of cloned eukaryotic genes have been developed as a means of identifying DNA sequences that are necessary for normal gene function.
Abstract: The alpha-like and beta-like subunits of human hemoglobin are encoded by a small family of genes that are differentially expressed during development. Through the use of molecular cloning procedures, each member of this gene family has been isolated and extensively characterized. Although the alpha-like and beta-like globin genes are located on different chromosomes, both sets of genes are arranged in closely linked clusters. In both clusters, each of the genes is transcribed from the same DNA strand, and the genes are arranged in the order of their expressions during development. Structural comparisons of immediately adjacent genes within each cluster have provided evidence for the occurrence of gene duplication and correction during evolution and have led to the discovery of pseudogenes, genes that have acquired numerous mutations that prevent their normal expression. Recently, in vivo and in vitro systems for studying the expression of cloned eukaryotic genes have been developed as a means of identifying DNA sequences that are necessary for normal gene function. This article describes the application of an in vitro transcription procedure to the study of human globin gene expression.
201 citations
TL;DR: A mouse α-globin-related pseudogene completely lacks intervening sequences, and could not code for a functional globin polypeptide because of frameshifts; the widespread occurrence of globin pseudogenes in other species suggests that they are not ‘dead’ genes but may be important in controlling globin expression.
Abstract: A mouse α-globin-related pseudogene (ψα30.5) completely lacks intervening sequences, and could not code for a functional globin polypeptide because of frameshifts. The widespread occurrence of globin pseudogenes in other species suggests that they are not ‘dead’ genes but may be important in controlling globin expression.
131 citations
TL;DR: In this paper, the complete DNA sequences of three human kappa variable region (V kappa) genes isolated from fetal liver DNA were reported, and the sequences demonstrate that two non-allelic genes encoding subgroup I proteins have more than 90% nucleotide homology in both proteins coding and non-coding regions.
Abstract: The study of immunoglobulin genes at the molecular level can allow us to elucidate the origin of antibody diversity. Investigations of immunoglobulin gene structure in the mouse have shown that light chains are encoded by three gene segments: the C gene encoding the constant region and the V and J genes encoding the variable region. In antibody-producing cells the V and J genes join together to create a complete immunoglobulin gene. No data are available on the structure of human light chain variable region genes, but the variable regions of over 150 human kappa light chain proteins have been sequenced and they comprise four distinct subgroups. Here we report the complete DNA sequences of three human kappa variable region (V kappa) genes isolated from fetal liver DNA. The sequences demonstrate that two non-allelic genes encoding subgroup I proteins have more than 90% nucleotide homology in both proteins coding and non-coding regions. Comparison of these human genes with two complete DNA sequences of mouse V kappa genes shows that V kappa gene structure is highly conserved between the two species, which suggests that V kappa genes rearrange during the differentiation of human lymphocytes by a very similar mechanism to that in the mouse. The sequence of a defective V kappa gene is also described--this gene is unable to code for a functional immunoglobulin due to substitutions, deletions and insertions in its sequence. It is analogous to the pseudogenes of globin and Xenopus 5S RNA.
117 citations
TL;DR: An examination of the DNA sequences at the intron/exon junctions suggests that a putative ψβ2 precursor mRNA could not be spliced normally and compares the flanking and noncoding sequences of ψ β2 and β1 and discusses the evolutionary relationship between these two genes.
103 citations
TL;DR: Comparison of the sequences of some of these genes to one another indicates that chromosomal DNA is a dynamic structure and that each gene locus is much more complex than was originally supposed.
Abstract: Structural and functional analysis of the mouse alpha-globin and beta-globin genes reveals that the globin genes are encoded in discontinous bits of coding information and that each gene locus is much more complex than was originally supposed. Each seems to consist of an array of several authentic genes as well as several apparently inactive pseudogenes. Comparison of the sequences of some of these genes to one another indicates that chromosomal DNA is a dynamic structure. Flanking and intervening sequences change in two ways: quickly, by duplication and extensive insertions and deletions, and slowly, by point mutation. Active coding sequences are usually limited to the slower mode of evolution. In addition to identifying fast and slow modes of evolution, it has also been possible to test the function of several signals that surround these genes and to identify those that appear to play a role in gene expression.
87 citations
TL;DR: Pulse-labeling studies of these three closely linked genes suggest that in estrogen-stimulated oviduct, the markedly different steady-state levels of the X, Y, and ovalbumin gene transcripts reflect their differential transcription rates.
Abstract: We describe the isolation of recombinant phages from a chicken gene library which contain two genes designated X and Y. These two genes are linked to the ovalbumin gene (OV) in the order 5'-X-Y-ovalbumin-3' [Royal, A., Garapin, A., Cami, B., Perrin, F., Mandel, J. L., LeMeur, M., Bregegegre, F., Gannon, F, LePennec, J. P., Chambon, P., & Kourilsky, P. (1979) Nature (London) 279, 125-132]. Both genes contain multiple intervening sequences and share limited sequence homology with the authentic ovalbumin gene but are expressed in oviduct cells at different levels. X and Y hybridization probes were prepared in order to study the expression and the relative hormonal responsiveness of these three genes in chicken oviduct. The sequence specificity of the probes was demonstrated by Southern hybridization assays. Northern hybridization studies using the X and Y gene probes indicated the presence of putative precursor molecules in stimulated oviduct ribonucleic acid preparations, which differ in size from those observed for ovalbumin. R0t analysis has demonstrated that, similar to the ovalbumin gene, the level of X and Y gene transcripts is increased by the steroid hormone estrogen, but to varying degrees. The extent of hormonal responsiveness of the three closely related genes is in the order (normalized) relative to ovalbumin of OV:Y:X congruent to 100:10:1. Pulse-labeling studies of these three closely linked genes suggest that in estrogen-stimulated oviduct, the markedly different steady-state levels of the X, Y, and ovalbumin gene transcripts reflect their differential transcription rates.
37 citations
TL;DR: A derivative of bacteriophage f1 is constructed which contains an amber mutation in the major coat protein gene (gene VIII) plus an additional wild-type copy of this gene in the intergenic space near the origin of phage DNA replication.
34 citations
TL;DR: Recombination sites for heavy chain class switching fell within these repeated sequences, suggesting that recombination between partially homologous blocks of repeat sequences 5' to CH genes generates the deletion responsible for class switching.
Abstract: We have used heteroduplex analysis to investigate the sequences surrounding the germline C gamma 1 and C gamma 3 genes, and to compare them with those surrounding the C mu gene. We detected an inverted pseudogene 5' to the C gamma 3 gene and 50-65% homologous to it. A 400 bp region of the C gamma 1 and C gamma 3 3' flanking sequences was conserved as strongly as the genes (65-80%), suggesting it may have a specific function. The sequences 5' to the C gamma 1 and C gamma 3 genes and possibly also the C mu gene are composed of tandem partially homologous repeats of a similar 250 bp unit, arranged in the case of the C gamma 1 gene, in 2-5 kb blocks of alternating orientation. These repeats comprised over 13 kb of the spacer region separating the C gamma 3 and C gamma 1 genes. Recombination sites for heavy chain class switching fell within these repeated sequences, suggesting that recombination between partially homologous blocks of repeat sequences 5' to CH genes generates the deletion responsible for class switching. This hypothesis was strongly supported by an examination of published nucleotide sequences around the recombination sites of rearranged C gamma 1 and C gamma 2b genes (1,2).
7 citations
Journal Article•
TL;DR: A detailed analysis of intergene DNA has revealed the presence of different types of repetitive DNA sequences in the vicinity of many of the globin genes but the significance of this finding with regard to the control of globin gene expression is not yet known.
Abstract: A very precise picture of the fine structure and organization of the human globin genes has recently emerged from the study of cloned fragments of chromosomal DNA containing the globin genes and their flanking DNA. The precise sizes, locations and nucleotide sequences of intervening sequences (introns) that interrupt the globin genes have been determined. A number of presumably functionally important preserved nucleotide sequences common to all of the globin genes have been identified within the 5'-flanking DNA of the genes, as well as in their untranslated sequences and at the junctions between coding and intervening sequences. Intergene distances as well as the sizes of duplication units of closely related genes have been determined. A somewhat unexpected finding has been the identification of apparently nonexpressed globin pseudogenes within the globin gene clusters. Finally, detailed analysis of intergene DNA has revealed the presence of different types of repetitive DNA sequences in the vicinity of many of the globin genes but the significance of this finding with regard to the control of globin gene expression is not yet known.
01 Jan 1980
TL;DR: In this paper, the authors describe the isolation of recombinant phages from a chicken gene library which contain two genes designated X and Y. These two genes are linked to the ovalbumin gene (OV) in the order 5'-X-Y-ovalbumin-3' and are expressed in oviduct cells at different levels.
Abstract: We describe the isolation of recombinant phages from a chicken gene library which contain two genes designated X and Y. These two genes are linked to the ovalbumin gene (OV) in the order 5'-X-Y-ovalbumin-3' [Royal, A., Garapin, A., Cami, B., Perrin, F., Mandel, J. L., LeMeur, M., Bregegegre, F., Gannon, F, LePennec, J. P., Chambon, P., & Kourilsky, P. (1979) Nature (London) 279, 125-132]. Both genes contain multiple intervening sequences and share limited sequence homology with the authentic ovalbumin gene but are expressed in oviduct cells at different levels. X and Y hybridization probes were prepared in order to study the expression and the relative hormonal responsiveness of these three genes in chicken oviduct. The sequence specificity of the probes was demonstrated by Southern hybridization assays. Northern hybridization studies using the X and Y gene probes indicated the presence of putative precursor molecules in stimulated oviduct ribonucleic acid preparations, which differ in size from those observed for ovalbumin. R0t analysis has demonstrated that, similar to the ovalbumin gene, the level of X and Y gene transcripts is increased by the steroid hormone estrogen, but to varying degrees. The extent of hormonal responsiveness of the three closely related genes is in the order (normalized) relative to ovalbumin of OV:Y:X congruent to 100:10:1. Pulse-labeling studies of these three closely linked genes suggest that in estrogen-stimulated oviduct, the markedly different steady-state levels of the X, Y, and ovalbumin gene transcripts reflect their differential transcription rates.