Showing papers on "Chromosomal region published in 1982"

Human c-myc onc gene is located on the region of chromosome 8 that is translocated in Burkitt lymphoma cells

Abstract: Human sequences related to the transforming gene (v-myc) of avian myelocytomatosis virus (MC29) are represented by at least one gene and several related sequences that may represent pseudogenes. By using a DNA probe that is specific for the complete gene (c-myc), different somatic cell hybrids possessing varying numbers of human chromosomes were analyzed by the Southern blotting technique. The results indicate that the human c-myc gene is located on chromosome 8. The analysis of hybrids between rodent cells and human Burkitt lymphoma cells, which carry a reciprocal translocation between chromosomes 8 and 14, allowed the mapping of the human c-myc gene on region (q24 leads to qter) of chromosome 8. This chromosomal region is translocated to either human chromosome 2, 14, or 22 in Burkitt lymphoma cells.

Organization, structure, and assembly of immunoglobulin heavy chain diversity DNA segments.

Abstract: We have identified, cloned, and sequenced eight different DNA segments encoding the diversity (D) regions of mouse immunoglobulin heavy-chain genes. Like the two D segments previously characterized (16, 17), all eight D segments are flanked by characteristic heptamers and nonamers separated by 12-bp spacers. These 10 D segments, and several more D segments identified but not yet sequenced, can be classified into three families based on the extent of sequence homology. The SP2 family consists of nine highly homologous D segments that are all 17-bp long and clustered in a chromosomal region of approximately 60 kb. The FL16 family consists of up to four D segments, two of which were mapped in the 5' end region of the SP2-D cluster. The two FL16D segments are 23 and 17 bp long. The third, the Q52 family, is a single-member family of the 10-bp-long DQ52, located 700 bp 5' to the JH cluster. We argue that the D-region sequences of the majority of heavy chain genes arise from these germline D segments by various somatic mechanisms, including joining of multiple D segments. We present a specific model of D-D joining that does not violate the 12/23-bp spacer rule.

Identification of haplotypes of the chicken major histocompatibility complex (B).

Abstract: The chromosomal region presently known to contain the major histocompatibility complex of the chicken was first detected in 1947 using alloimmune hemagglutinating reagents and was tentatively assigned the locus symbol D in studies on the time of development of cellular antigens (Briles et al. 1948) and on its role in inducing hemolytic disease among chicks from alloimmunized hens (Briles 1948). The locus symbol was subsequently changed to B to symbolize the second chicken blood group system discovered at the University of Wisconsin (Briles et al. 1950). One of two blood group loci discovered independently by Gilmour (1959) was shown by an exchange of antisera to correspond to the Wisconsin B system. The early recognition that blood group systems were characterized by extensive polymorphism within rather narrowly based genetic stocks of chickens (Briles et al. 1957, Gilmour 1959) placed emphasis on investigating their possible effects on fitness and survival within populations or experimental crosses. As a result of this emphasis on within-laboratory studies, there was little sustained interest during the 1950-1970 period in the development of a broadly applicable system of uniform haplotype terminology. The discovery of histocompatibility-linked immune response genes in mammals (Benacerraf and McDevitt 1972) and the subsequent demonstration of immune response (Giinther et al. 1974, Benedict et al. 1975) and disease resistance (Hansen et al. 1967, Briles and Oleson 1971) associated with particular alleles at the B locus in the chicken created a need for information regarding possible haplotype homologies between genetic stocks being studied in separate laboratories. The technique for detecting possible homologies between lines was utilized from the beginning of the work at Texas A and M University (Briles 1952, Briles et al. 1957) and, soon after establishing work on a diverse group of mildly inbred lines at the DeKalb AgResearch Laboratory in early 1958, a common haplotype terminology across lines was developed and later published in part to illustrate frequency profiles in inbred parent lines of chickens (Briles 1972). More recently, as a consequence of reagent preparation in a genetically diverse chicken colony at Northern Illinois University combined with the typing of

Principles and Practice of Recombinant DNA Research with Yeast

Abstract: INTRODUCTION Recombinant DNA research shows great promise in furthering understanding of yeast biology by making possible the analysis and manipulation of yeast genes not only in the test tube but also in yeast cells. The intent of this paper is to summarize the major features of current technology and to outline some implications for the immediate future of yeast molecular biology. There now exist simple and general methods for isolating and amplifying virtually any yeast gene, although these methods generally require an intermediate step in Escherichia coli. Powerful and exquisitely sensitive hybridization methods have been developed that allow direct physical analysis of any chromosomal region containing a gene that has been molecularly cloned. Most importantly, it is now possible to return to yeast, by transformation with DNA, cloned genes using a variety of selectable marker systems developed for this purpose. These technological advances have combined to make feasible truly molecular as well as classical genetic manipulation and analysis in yeast. The many uses to which these new tools have already been put have recently been reviewed by Olson (1981), and the results that have been obtained are to be found scattered in many of the papers in this volume. The biological problems that have been most effectively addressed by recombinant DNA technology are ones that have the structure and organization of individual genes as their central issue. Thus, the reader will find elsewhere in this volume that many signal advances in the understanding of such diverse subjects as the switching...

Physical map of the white locus of Drosophila melanogaster

Abstract: The white locus of Drosophila melanogaster is a genetically well-characterized locus, mutations in which alter the degree of pattern of pigmentation of the eyes Using a previously cloned DNA segment containing a portion of the white locus of a mutant allele, we have cloned and characterized the DNA of a 48-kilobase chromosomal region of the Canton S wild-type strain We have mapped the positions, relative to restriction endonuclease cleavage sites, of several previously characterized chromosomal rearrangement breakpoints that bracket the while locus These results define a segment of 14 kilobase that contains all of the white locus sequences necessary for the production of a wild-type eye color phenotype By conventional criteria, no repetitive sequences are present within this 14-kilobase segment; however, we have identified an extremely weak DNA sequence homology between a portion of this segment and a chromosomal region in the vicinity of the zeste locus

Single-copy and amplified CAD genes in Syrian hamster chromosomes localized by a highly sensitive method for in situ hybridization.

Abstract: Syrian hamster cells resistant to N-(phosphonacetyl)-L-aspartate (PALA), a specific inhibitor of the aspartate transcarbamylase activity of the multifunctional protein CAD, overproduce this protein as a result of amplification of the CAD gene. The authors have used a sensitive in situ hybridization technique to localize CAD genes in spreads of metaphase chromosomes from several independent PALA-resistant lines and from wild-type PALA-sensitive cells. The amplified genes were always found within chromosomes, usually in an expanded region of the short arm of chromosome B9. In wild-type cells, the CAD gene was also on the short arm of chromosome B9. In one mutant line, 90 to 100 CAD genes were found within an expanded B9 chromosome and 10 to 15 more were near the distal end of one arm of several different chromosomes. Another line contained most of the genes in a telomeric chromosome or large chromosome fragment. The amplified genes were in chromosomal regions that were stained in a banded pattern by trypsin-Giemsa. A few double minute chromosomes were observed in a very small fraction of the total spreads examined. The in situ hybridizations were performed in the presence of 10% dextran sulfate 500, which increases the signal by as much as 100-fold.more » Using recombinant DNA plasmids nick-translated with -/sup 125/I)dCTP to high specific radioactivity, 10 CAD genes in a single chromosomal region were revealed after 1 week of autoradiographic exposure, and the position of the unique gene could be seen after 1 month.« less

Cytological Hybridization to Mammalian Chromosomes

Abstract: Publisher Summary This chapter compares the procedures related to the use of molecular hybridization in mammalian chromosomes. Optimal conditions for cytological hybridization include general methodology, kinetic considerations, and methods for analysis. The localization of satellite DNA sequences or sequences involving the rDNA complex in primates and other mammals has allowed comparative studies on evolution of the chromosome complement, to be made at the molecular level. Cytological hybridization helps to demonstrate the chromosomal integration of DNA from exogenous sources, such as viral DNA or DNA inserted as the result of DNA-mediated transformation. Physical mapping of genes or any DNA sequence to chromosomes can be accomplished directly by hybridization to chromosomal DNA. The use of cytological hybridization is limited to reiterated sequences. A probe binding to a reiterated region produces more grains than other portions of the probe hybridized to less reiterated regions, thus confounding the assignment. The concentration in the probe of any fraction or partial fraction that hybridizes with a chromosomal region can be calculated from the time course of the reaction to that region. The chapter also discusses the problems and prospective of this technique.

Amplified DNA sequences in Y1 mouse adrenal tumor cells: association with double minutes and localization to a homogeneously staining chromosomal region.

Abstract: DNA associated with double minutes (dm) of the Y1-DM mouse adrenocortical tumor cell line has been cloned in Charon 4A and a preliminary characterization has been made of a recombinant clone, lambda Y1dm-1, isolated from this dm DNA library [George, D. L. & Powers, V. E. (1981) Cell 24, 117--123]. Cloned sequences in lambda Y1dm-1 are amplified in the genome of the Y1-DM cells. They are also amplified in the genome of a related Y1 subline (Y1-HSR), which has a homogeneously staining chromosomal region (HSR). Here we report that the amplified sequences complementary to lambda Y1dm-1 are localized in the HSR, as determined by in situ hybridization. In addition, we found that a population of Y1-DM cells originally containing only dm later consisted of two cell types. Some cells retained dm; others had lost dm but gained a HSR-bearing chromosome morphologically distinct from that in the Y1-HSR cell line. Subclones isolated from this mixed culture have either dm or a HSR, but not both. Southern blotting studies revealed that genomic DNA samples from subclones with a HSR, like subclones with dm, still possess amplified copies of DNA homologous to our recombinant probe. These experiments provide direct evidence that the dm and HSRs in these Y1 cells are structurally related and further support the hypothesis that these chromosomal anomalies result from a process of gene amplification.

Cloning and characterization of the Escherichia coli chromosomal region surrounding the dnaG Gene, with a correlated physical and genetic map of dnaG generated via transposon Tn5 mutagenesis.

Abstract: A 24 kilobase pair region of the E. coli chromosome surrounding the dnaG gene has been cloned and characterized. A lambda phage library was constructed by ligating a Sau3A( decreases GATC) partial DNA digest of the entire E. coli chromosome into the lambda BamHI(G decreases GATCC) cloning vector charon 28. Partial digestion was performed to generate overlapping chromosomal fragments and to allow one to walk along the chromosome. This library was probed with a nick-translated plasmid (pRRBl) containing the rpoD gene, which maps adjacent to dnaG at 66 min. Four bacteriophages: lambda 3, lambda 4, lambda 5, lambda 6 that hybridized to the probe were isolated from the 2,500 plaques screened. One phage recombinant lambda 4, was shown to contain the dnaG gene. Three recombinant plasmids containing dnaG: pGL444, pGL445, pBS105, were constructed via subcloning of lambda 4 using different restriction of fragments. Plasmids pGL444 and pBS10 5 were subjected to transposon Tn5 mutagenesis and 88 Tn5 inserts into the cloned region were isolated. The location of the Tn5 inserts were mapped by restriction enzyme analysis of the plasmids and the insertion mutations were checked for ability to complement of dnaGts chromosomal marker at nonpermissive 40 degrees C. In this manner a correlated physical and genetic map of dnaG was determined. A large number of Tn5 inserts map to a specific 900 b.p. region which we propose may be involved in the regulation of dnaG gene expression.

Molecular cloning of the spo0B sporulation locus in bacteriophage lambda.

Abstract: The stage 0 sporulation locus spo0B has been mapped by transformation between the pheA and spoIVF loci. Analysis of the behavior of alleles of the spo0B locus in trpE26 merodiploid strains indicates that all of the known alleles of this locus comprise a single complementation group. The spoIVF88 mutation was found to reside in a separate complementation group. The chromosomal region surrounding and including the spo0B locus was cloned in the lambda vector Charon 4A. Extensive restriction endonuclease analyses of the inserts in these phage revealed that an EcoRI fragment of DNA of 2.3 kilobases had transforming activity for spo0B mutations. Examination of the physical and genetic maps of the locus suggested that the entire spo0B locus is contained within this fragment. Subcloning of restriction endonuclease fragments of the lambda inserts and transformation analyses allowed assignment of surrounding genetic loci to specific DNA fragments.

Highly polymorphic DNA site D14S1 maps to the region of Burkitt lymphoma translocation and is closely linked to the heavy chain γ1 immunoglobulin locus

Abstract: Using a phage λ Charon 4A recombinant DNA clone (λCH4A-rHs18) from a human genomic library, Wyman and White detected a multiallelic common polymorphism at an EcoRI site (D14S1) flanking the DNA region homologous to the probe [Wyman, A. R. & White, R. (1980) Proc. Natl. Acad. Sci. USA 77, 6754-6758]. Subsequent studies, carried out with the cell hybrid approach and the use of a subclonal derivative (pAW101) from λCH4A-rHs18 have assigned this locus to autosome 14 between 14q21 and 14qter [De Martinville, B., Wyman, A. R., White, R. & Franke, U. (1982) Am. J. Hum. Gen. 34, 216-226]. The data presented here permit the precise mapping of this locus to the subtelomeric region of autosome 14, below band 14q32, in close proximity to the heavy chain γ1 immunoglobulin locus. These conclusions are supported by three independent lines of evidence, including studies on gene dosage, somatic cell hybrids, and pedigree analysis. Our results are in agreement with the recent assignment of the heavy chain γ1 immunoglobulin locus to band 14q32 [Kirsch, I. R., Morton, C. C., Nakahara, K. & Leder, P. (1982) Science 216, 301-303] and are consistent with the generally held contention that one unit of meiotic recombination corresponds approximately to one million base pairs. It is to be expected that the location of the highly polymorphic D14S1 site at a measurable distance from the cluster of the heavy chain genes will provide new opportunities for a genetic approach to the question of the specific gene order within the cluster, its possible individual variation, and its biological significance in normal development and disease. It is worthwhile to point out that such a highly polymorphic DNA sequence is located in the same chromosomal region where so much somatic rearrangement goes on normally (i.e., switch region between classes of heavy chain constant region genes) and which is involved with de novo translocations associated with malignancies.

Developmental inactivity of 5S RNA genes persists when chromosomes are cut between genes.

Abstract: Xenopus and other amphibians possess two major classes of 5S RNA genes1. One class, which codes for somatic-type 5S RNA, is expressed in both oocytes and somatic cells2. The other class, which is 50 times more abundant and encodes oocyte-type 5S RNA, is expressed in oocytes but not in somatic cells2–4. The oocyte-type 5S genes are located in tandem arrays of hundreds of genes at the ends of most chromosomes5, and it has been postulated that the lack of expression of oocyte-type 5S RNA genes in somatic cells is due to some general characteristic of the chromosomal region which the genes occupy6, for example, a folding into heterochromatin or higher-order structures. An alternative possibility is that the inactivity of these genes is controlled individually, and is independent of adjacent genetic material. We have now distinguished between these two possibilities by testing the transcription of oocyte-type 5S RNA genes either in their normal arrangement on intact chromosomes or after each gene has been separated from its neighbours by micrococcal nuclease digestion. Transcription was assayed by injecting intact nuclei, containing the 5S RNA genes as chromatin, into Xenopus oocytes7. We find that the developmental inactivity of oocyte-type 5S RNA genes is retained after the chromatin is cleaved into fragments the size of individual gene repeats.

Isolation of an autonomously replicating DNA fragment from the region of defective bacteriophage PBSX of Bacillus subtilis.

Abstract: We have isolated a 5.4-kilobase fragment of Bacillus subtilis DNA that confers the ability to replicate upon a nonreplicative plasmid. The B. subtilis 168 EcoRI fragment was ligated into the chimeric plasmid pCs540, which contains a chloramphenicol resistance determinant from the Staphylococcus aureus plasmid pC194 and an HpaII fragment from the Escherichia coli plasmid, pSC101. A recE B. subtilis derivative, strain BD224, is capable of maintaining this DNA as an autonomously replicating plasmid. In rec+ recipients, chloramphenicol-resistant transformants do not contain free plasmid. The plasmid is integrated as demonstrated by alterations in the pattern of chromosomal restriction enzyme fragments to which the plasmid hybridizes. The site of plasmid integration was mapped by PBS1-mediated transduction to the metC-PBSX region. A strain was a deletion in the region of defective bacteriophage PBSX differs in the hybridization profile obtained by probing EcoRI digests with this cloned fragment. This same deletion mutant, though proficient in normal recombinational pathways, permits autonomous replication of the plasmid apparently owing to the lack of an homologous chromosomal region with which to recombine. We believe that, like E. coli. B. subtilis contains at least one DNA fragment capable of autonomous replication when liberated from its normally integrated chromosomal site and that this cloned DNA fragment comes from the region of defective bacteriophage PBSX. Images

The effect of exogenous DNA insertion at a chromosomal region containing rDNA

Abstract: We have previously shown that exogenous DNA may be incorporated into host cell chromosomes following DNA-mediated gene transfer (transformation). Discrete chromosomal changes often accompany the integ

The fate of several migrant genes in isolated populations of Drosophila melanogaster

Abstract: Sepia-eyed flies carrying the slow electrophoretic variant of either Est-6 or Adh were introduced in low numbers and at infrequent intervals into populations of wildtype flies (+ se /+ se ) that were also homozygous for the fast moving variant of either Est-6 (50 populations) or Adh (50 populations). After 24 generations, the frequency of the sepia alleles was approximately 25%, although there was considerable variation from population to population. The fate of the Est-6 slow allele corresponded closely to that of sepia (which is located ten map units distant), although one population retained the slow allozyme variant but rejected sepia. The Adh slow allele was also retained by many populations. A number of them retained Adh-S but not sepia, and vice versa; these loci are on different chromosomes. The advantage of sepia heterozygotes was estimated to be about twice that of wildtype homozygotes. The data suggest that the selective advantage resides not with the sepia locus itself, but with a nearby chromosomal region.

Characterization of additional rabbit IgM allotypes and the effect of suppression of a VH locus allotypes on the expression of n C mu locus allotypes.

Abstract: Anti-allotype antisera were produced that identified eight rabbit IgM allotypic specificities, n80, n81, n82, n83, n84, n85, n86, and n87 The n locus Cmu genes controlling these IgM allotypic specificities are closely linked to the a (VH subgroup) locus The genes controlling these allotypic specificities were found to be in the heavy chain chromosomal region and were assigned to 11 haplotypes present in our rabbit colony The n locus and a locus genes appeared in the haplotypes in six combinations: a/sup 1/n/sup 81/, a/sup 2/n/sup 81,n87/, a/sup 1/n/sup 80,83/, a/sup 2/n/sup 80,82,87/, a/sup 3/n/sup 81,84,85/ and a/sup 3/n/sup 80,84,86,87/ By radioprecipitation analysis, 70 to 80% of serum IgM reacts with the antiserum directed to each n locus allotypic specificity found encoded in one haplotype; thus, each allotypic specificity of the haplotype is present on the same IgM molecule When sera from a locus allotype-suppressed homozygous rabbits were tested for expression of each n locus allotypic specificity, n80, n81, and n87 were still expressed, whereas n82, n83, n84, n85, and n86 were not These data provide direct evidence that some IgM specificities are expressed independently of the a locus (ie, ''true''), and other s are dependent on the expression of anmore » a locus specificity (ie, conformational) The expression of the ''true'' allotypic specificities probably reflects genetic control of the germline Cmu gene, and the expression of ''conformationally dependent'' allotypic specificities probably reflects the interaction of VH and Cmu gene segments This distinction is important and must be recognized when evaluating the genetics and structure of the IgM molecule« less

HLA systems and rheumatic diseases.

Abstract: HLA refers to a region on the short arm of the 6th chromosome in man. It encompasses genes of immunobiological importance controlling inter alia cell surface determinants, transplantation antigens responsible for organ and tissue graft rejection, complement components, immune responses and a variety of different disease susceptibilities. Homologous regions have been found in all mammals investigated; the region is known as H-2 in the mouse. Studies in the latter were of great help in developing our current ideas on the fine structure and function of HLA. Early work in mice (Snell 1948) showed that the control of rejection of tumours grafted from one inbred strain to another was confined predominantly to a single chromosomal region and was of overriding importance in tissue and organ graft rejection. It was accordingly named the major histocompatibility complex (MHC). Other gene products in this region were subsequently identified by a variety of serological and cellular in vitro techniques. There are comparable histocompatibility genes within HLA that are responsible for rejection of organs and tissue in man. Singal et al. (1969) showed that recipients of a kidney from an HLA identical sibling donor do remarkably well whereas recipients of an HLA incompatible sibling donor do relatively poorly (90% vs 50% 2-year survival rates respectively).

Localization of tRNA genes of Drosophila melanogaster by in situ hybridization.

Abstract: Six purified tRNAs labeled with 125I by chemical or enzymatic methods were hybridized to polytene chromosomes of Drosophila melanogaster. The main chromosomal regions of hybridization wer: tRNAGly(GGA), 58A, 84C, and 90E; tRNALeu(2), 44E, 66B5-8, and 79F; tRNASer(2b), 86A, 88A9-12, and 94A6-8; tRNAThr(3), 47F and 87B; tRNAThr(4), 93A1-2; and tRNATyr(1 gamma), 19F, 22F-23A, 41, 50C1-4 and 85A. At 50C the hybridization of tRNATyr(1 gamma) was polymorphic in the giant strains. When the hybridization of three valine isoacceptors studied previously was re-investigated, it was found that only one hybridization site, 90BC, was shared between tRNAVal(3b) and tRNAVal(4). tRNAVal(3a) did not have any sites in common with the other two.

Formation of F'trp plasmids in Escherichia coli K12.

Abstract: From strains carrying two different F-prime factors, we recovered F' derivatives that acquired the trp chromosomal region. These F'trp plasmids can be isolated at a frequency of 10-5 to 10-6. They were characterized genetically by looking at the size of the trp segment they acquired and at the location of that segment in the parental F' plasmid. Results are discussed in relationship to possible transposition mechanisms.