Showing papers on "Chromosome 22 published in 1986"
TL;DR: It is suggested that a common event underlies tumorigenesis in acoustic neuroma and meningioma, and this finding might provide a clue to the chromosomal location of the defective gene in bilateral acoustic neurofibromatosis, an auto-somal dominant disorder with the hallmark of bilateral acoustic neuromas.
Abstract: The application of recombinant DNA techniques has identified two fundamental mechanisms of tumorigenesis in man. The first involves a qualitative or quantitative change in an oncogene (see ref. 1 for review). In the second, discovered in embryonal tumours, a primary mutation occurs which is recessive at the cellular level to the normal allele. The growth of a tumour ensues only after a secondary change, such as chromosome loss or mitotic recombination, eliminates the normal allele, thereby unmasking the altered allele. Because its effect is recessive, the primary mutation may also occur and be transmitted in the germ line, resulting in a familial pattern for the disease. In familial cases, independent bilateral tumours are common, since the tumours result from a single event--loss of the normal genes--which can occur in any cell. This contrasts with non-familial (sporadic) cases where solitary tumours result from the infrequent occurrence of two rare events within the same cell. By a molecular genetic approach we have now shown that acoustic neuroma, one of the most common tumours of the human nervous system, is specifically associated with loss of genes on human chromosome 22 and may result from the mechanism of tumorigenesis discovered in embryonal tumours. This finding might provide a clue to the chromosomal location of the defective gene in bilateral acoustic neurofibromatosis, an autosomal dominant disorder with the hallmark of bilateral acoustic neuromas. In view of the frequent occurrence of meningiomas in patients with bilateral acoustic neurofibromatosis and the association of meningioma with loss of chromosome 22 previously reported in cytogenetic studies, we suggest that a common event underlies tumorigenesis in acoustic neuroma and meningioma.
485 citations
TL;DR: A clone that cross-hybridizes with a mouse p53 probe has been isolated from a cDNA library of simian virus 40-transformed human fibroblasts and results show that the human p53 gene is located on chromosome 17.
Abstract: A clone that cross-hybridizes with a mouse p53 probe has been isolated from a cDNA library of simian virus 40-transformed human fibroblasts. This cloned human p53 cDNA was used as a probe to examine DNAs obtained from human-rodent somatic cell hybrids that have segregated human chromosomes. The results show that the human p53 gene is located on chromosome 17. In addition, Southern analysis of hybrids prepared from human cells containing a chromosome 17 translocation allowed regional localization of the human p53 gene to the most distal band on the short arm of this chromosome (17p13). Localization of the p53 gene to 17p13 was confirmed by in situ hybridization of metaphase spreads with the human p53 probe.
353 citations
TL;DR: The c-erbB-2 gene is a v-erb B-related proto-oncogene which is distinct from the gene encoding the epidermal growth factor receptor, and a specific breakpoint observed in a translocation associated with acute promyelocytic leukemia is mapped.
Abstract: The c-erbB-2 gene is a v-erbB-related proto-oncogene which is distinct from the gene encoding the epidermal growth factor receptor. By using two independent methods, hybridization of both sorted chromosomes and metaphase spreads with cloned c-erbB-2 DNA, we mapped the c-erbB-2 locus on human chromosome 17 at q21, a specific breakpoint observed in a translocation associated with acute promyelocytic leukemia. Furthermore, we observed amplification and elevated expression of the c-erbB-2 gene in the MKN-7 gastric cancer cell line. These data suggest possible involvement of the c-erbB-2 gene in human cancer.
343 citations
341 citations
Journal Article•
TL;DR: The results suggest a deletion map of the Y chromosome, in which each of the 23 Y-specific restriction fragments tested can be assigned to one of seven intervals, and the polarity of this map with respect to the long and short arms of theY chromosome is established.
Abstract: The genomes of 27 individuals (19 XX males, two XX hermaphrodites, and six persons with microscopically detectable anomalies of the Y chromosome) were analyzed by hybridization for the presence or absence of 23 Y-specific DNA restriction fragments. Y-specific DNA was detected in 12 of the XX males and in all six individuals with microscopic anomalies. The results are consistent with each of these individuals carrying a single contiguous portion of the Y chromosome; that is, the results suggest a deletion map of the Y chromosome, in which each of the 23 Y-specific restriction fragments tested can be assigned to one of seven intervals. We have established the polarity of this map with respect to the long and short arms of the Y chromosome. On the short arm, there is a large cluster of sequences homologous to the X chromosome. The testis determinant(s) map to one of the intervals on the short arm.
331 citations
TL;DR: To identify gene products that function stoichiometrically in mitotic chromosome transmission, genes were cloned on high copy number plasmids and transformed into yeast cells, and the transformants were examined for an increase in the frequency of mitotic chromosomes loss or recombination resulting from the gene imbalance.
315 citations
TL;DR: It is suggested that the chromosome 17 and X alpha satellite subsets may be related components of a larger alphoid subfamily which have evolved from a common ancestral repeat into the contemporary chromosome-specific subsets.
Abstract: The centromeric regions of all human chromosomes are characterized by distinct subsets of a diverse tandemly repeated DNA family, alpha satellite. On human chromosome 17, the predominant form of alpha satellite is a 2.7-kilobase-pair higher-order repeat unit consisting of 16 alphoid monomers. We present the complete nucleotide sequence of the 16-monomer repeat, which is present in 500 to 1,000 copies per chromosome 17, as well as that of a less abundant 15-monomer repeat, also from chromosome 17. These repeat units were approximately 98% identical in sequence, differing by the exclusion of precisely 1 monomer from the 15-monomer repeat. Homologous unequal crossing-over is suggested as a probable mechanism by which the different repeat lengths on chromosome 17 were generated, and the putative site of such a recombination event is identified. The monomer organization of the chromosome 17 higher-order repeat unit is based, in part, on tandemly repeated pentamers. A similar pentameric suborganization has been previously demonstrated for alpha satellite of the human X chromosome. Despite the organizational similarities, substantial sequence divergence distinguishes these subsets. Hybridization experiments indicate that the chromosome 17 and X subsets are more similar to each other than to the subsets found on several other human chromosomes. We suggest that the chromosome 17 and X alpha satellite subsets may be related components of a larger alphoid subfamily which have evolved from a common ancestral repeat into the contemporary chromosome-specific subsets.
252 citations
TL;DR: The TGF-β locus in the mouse was mapped to chromosome 7 by hybridizing a murine cDNA probe to a Chinese hamster × mouse hybrid panel and a human 1050-bp EcoRI cDNA fragment was used to map the human locus for T GF-β.
Abstract: Transforming growth factors (TGF) are defined as biologically active polypeptides which reversibly confer the transformed phenotype onto untransformed cultured cells. They have been subdivided into two classes: type α and type β TGFs. TGF-β acts synergistically with TGF-α in inducing phenotypic transformation. TGF-β can also act as negative autocrine growth factor. A human 1050-bp EcoRI cDNA fragment was used to map the human locus for TGF-β by Southern blotting of DNA prepared from 17 human × Chinese hamster somatic cell hybrids. The humanspecific restriction fragments segregated with human chromosome 19 in all of 14 informative hybrids. All other human chromosomes were discordant with the TGF-β bands in at least four hybrids. After in situ hybridization of the tritiated TGF-β probe to normal human metaphase spreads, 151 silver grains were scored in 54 cells. Of 24 grains over chromosome 19, 16 grains (11%) lay over region 19q13.1 → q13.3. Of the 54 cells analyzed, 16 (30%) had label over region 19q13.1 → q13.3. Thus,TGFB is assigned to chromosome 19, subbands q13.1 → q13.3. TheTgf- β locus in the mouse was mapped to chromosome 7 by hybridizing a murine cDNA probe to a Chinese hamster × mouse hybrid panel. Human chromosome 19 and proximal mouse chromosome 7 share another four homologous loci.
217 citations
TL;DR: Ch Chromosomal localization may provide a better understanding of the relationship of p53 to other human cellular genes and of its possible role in malignancies associated with specific chromosomal rearrangements.
Abstract: The p53 gene codes for a nuclear protein that has an important role in normal cellular replication. The concentration of p53 protein is frequently elevated in transformed cells. Transfection studies show that the p53 gene, in collaboration with the activated ras oncogene, can transform cells. Chromosomal localization may provide a better understanding of the relationship of p53 to other human cellular genes and of its possible role in malignancies associated with specific chromosomal rearrangements. A recent study mapped the human p53 gene to the long arm of chromosome 17 (17q21-q22) using in situ chromosomal hybridization. Here, by Southern filter hybridization of DNAs from human-rodent hybrids, we have localized the p53 gene to the short arm of human chromosome 17.
216 citations
TL;DR: It is demonstrated that K562 contains multiple remnants of a Ph1 chromosome with a breakpoint within bcr and thus may serve as a model system for the study of Ph1-positive chronic myelocytic leukemia at a molecular level.
Abstract: In the DNAs of all Ph1-positive chronic myelocytic leukemia patients studied to date, a breakpoint on chromosome 22 (the Ph1 chromosome) can be demonstrated with a probe from the bcr (breakpoint cluster region). Although the K562 cell line was established from cells of a chronic myelocytic leukemia patient, we have been unable to detect the Ph1 chromosome by cytogenetic means. Employing a probe from the 5' region of bcr, we have cloned an amplified Ph1 breakpoint fragment from K562. This demonstrates that K562 contains multiple remnants of a Ph1 chromosome with a breakpoint within bcr and thus may serve as a model system for the study of Ph1-positive chronic myelocytic leukemia at a molecular level. The isolation of bcr cDNA sequences shows that parts of bcr encode a protein. Employing K562, we demonstrate the presence of an abnormally sized mRNA species hybridizing to c-abl and to a bcr cDNA probe, indicating the possible consequence of the Ph1 translocation on a transcriptional level in chronic myelocytic leukemia. The isolation and sequencing of a cDNA containing the breakpoint area of this mRNA provide further evidence for its chimeric structure. Cloning of large stretches of chromosomal DNA flanking bcr and c-abl sequences in K562 and identification of the exons participating in the formation of the chimeric mRNA shows that a splice of at least 99 kilobases is made to fuse the 3' bcr exon to the 5' c-abl exon. Furthermore two chimeric cDNAs were isolated containing chromosome 9 sequences that map 43.5 kilobases downstream from the K562 breakpoint. These chromosome 9 sequences neither hybridize to the 8.5-kilobase chimeric c-abl mRNA nor to normal c-abl mRNAs in Hela cells and probably represent incorrect splicing products present in the K562 cell line.
200 citations
TL;DR: In this paper, the authors investigated the chromosome breakpoints in several cases of ALL carrying the t(9;22) translocation and found that the breakpoints on chromosome 22 occur within a 58-kilobase segment of DNA referred to as breakpoint cluster region.
Abstract: In chronic myelogenous leukemias (CML) with the t(9;22)(q34;q11) chromosome translocation the breakpoints on chromosome 22 occur within a 58-kilobase segment of DNA referred to as "breakpoint cluster region" (bcr) The same cytogenetically indistinguishable translocation occurs in approximately 10% of patients with acute lymphocytic leukemias (ALL) In this study we have investigated the chromosome breakpoints in several cases of ALL carrying the t(9;22) translocation In three of five cases of ALL we found that the bcr region was not involved in the chromosome rearrangement and that the 22q11 chromosome breakpoints were proximal (5') to the bcr region at band 22q11 In addition, we observed normal size bcr and c-abl transcripts in an ALL cell line carrying the t(9;22) translocation We conclude, therefore, that if c-abl is inappropriately expressed in ALL cells without bcr rearrangements, the genetic mechanism of activation must be different from that reported for CML
TL;DR: This work demonstrates how DNA sequence dosage analysis can be used to study genetic disorders that are not readily amenable to standard cytogenetic analysis.
Abstract: Most individuals with cat eye syndrome (CES) have a supernumerary bisatellited chromosome which, on the basis of cytogenetic evidence, has been reported to originate from either chromosome 13 or 22. To resolve this question, a single-copy DNA probe, D22S9, was isolated and localized to 22q11 by in situ hybridization to metaphase chromosomes. The number of copies of this sequence was determined in CES patients by means of Southern blots and densitometry analysis of autoradiographs. In patients with the supernumerary chromosome, four copies were found, whereas in one patient with a duplication of part of chromosome 22, there were three copies. Therefore, the syndrome results from the presence of either three or four copies of DNA sequences from 22q11; there is no evidence that sequences from other chromosomes are involved. This work demonstrates how DNA sequence dosage analysis can be used to study genetic disorders that are not readily amenable to standard cytogenetic analysis.
TL;DR: DNA analysis showed that the two deletions were different but included a common overlapping region likely to be essential for male determination, and showed a 46,X,Yp- karyotype.
Abstract: Structural anomalies of the sex chromosomes provide a means to study the location of genes responsible for sex determination. Recently, a type of sex reversal in humans, the 46,XX male, was shown to result in some cases from translocation of Y chromosome material to the X chromosome. In the present report, another type of sex reversal, the 46,XY female, is shown to result, in two cases, from small deletions of the short arm of the Y chromosome. Prometaphase chromosome analysis showed a 46,X,Yp- karyotype. Several Y chromosome-specific DNA probes were found to be deleted in the two female patients. DNA analysis showed that the two deletions were different but included a common overlapping region likely to be essential for male determination.
TL;DR: Ch Chromosome walking toward the centromeres reveals a group of repetitive sequences that occur only in the centromere regions of chromosomes I and II and at one other specific location in the S. pombe genome, presumably the Centromere of chromosome III.
Abstract: The Schizosaccharomyces pombe centromere-linked genes, LYS1 and CYH1 on chromosome I and TPS13 and RAN1 on chromosome II, have been isolated. The genetic order of these markers with respect to their centromeres was determined to establish relative directionality on the genetic and physical maps. Chromosome walking toward the centromeres reveals a group of repetitive sequences that occur only in the centromere regions of chromosomes I and II and at one other specific location in the S. pombe genome, presumably the centromere of chromosome III. The major class of large repeated sequence elements is 6.4 kilobases (kb) long (repeat K), portions of which occur at least twice on chromosome II and in several tandemly arranged intact copies at another centromeric location. Repeat K in turn contains groups of smaller repeats. Genetic recombination is strongly suppressed in the centromere II region, which contains at least 30 kb of repeated sequences. Centromeric DNA organization is much more complex in fission yeast than has been described in budding yeast (Saccharomyces cerevisiae), possibly because of the larger more condensed nature of the S. pombe chromosomes.
TL;DR: It was demonstrated that the Y DNA is located on the tip of the short arm of an X chromosome, which supports the hypothesis that XX maleness is frequently the result of transfer of Y DNA, including TDF, to a paternally derived X chromosome.
Abstract: Y-chromosomal DNA is present in the genomes of most human XX males. In these cases, maleness is probably due to the presence of the Y-encoded testis-determining factor (TDF). By means of in situ hybridization of a probe (pDP105) detecting Y-specific DNA to metaphases from three XX males, it was demonstrated that the Y DNA is located on the tip of the short arm of an X chromosome. This finding supports the hypothesis that XX maleness is frequently the result of transfer of Y DNA, including TDF, to a paternally derived X chromosome.
TL;DR: CDNA clones containing sequences coding for the murine neural cell adhesion molecule (N-CAM) were used in Southern hybridizations on human genomic DNA and demonstrated approximately 90% homology between human and murine NCAM genes.
Abstract: cDNA clones containing sequences coding for the murine neural cell adhesion molecule (N-CAM) were used in Southern hybridizations on human genomic DNA and demonstrated approximately 90% homology between human and murine NCAM genes. In situ hybridization with one of these clones was performed on human metaphase chromosomes and allowed the localization of the human NCAM gene to band q23 of chromosome 11. The genes for two other cell surface molecules believed to be involved in cell-cell interactions, Thy-1 and the delta chain of the T3-T cell receptor complex, have recently been localized to the same region of chromosome 11 in man. Moreover, this region of the human chromosome 11 appears to be syntenic to a region of murine chromosome 9 that also contains the staggerer locus: staggerer mice show abnormal neurological features which may be related to abnormalities in the conversion of the embryonic to the adult forms of the N-CAM molecule.
TL;DR: Since the strategy is a general one, the alpha satellite family of DNA should provide a rich source of molecular variation in the human genome and should contribute to the development of centromere-based genetic linkage maps of human chromosomes.
Abstract: We describe a general strategy for the detection of high-frequency restriction fragment length polymorphisms in the centromeric regions of human chromosomes by molecular analysis of alpha satellite DNA, a diverse family of tandemly repeated DNA located near the centromeres of all human chromosomes. To illustrate this strategy, cloned alpha satellite repeats isolated from two human chromosomes, 17 and X, have been used under high-stringency conditions that take advantage of the chromosome-specific organization of this divergent repeated DNA family. Multiple high-frequency restriction fragment length polymorphisms are described for the centromeric region of both chromosome 17 and X chromosome. Mendelian inheritance of the variants is demonstrated. The X-linked alpha satellite polymorphisms in particular are highly informative and constitute a virtually unique centromeric DNA marker for each X chromosome examined. Since the strategy we describe is a general one, the alpha satellite family of DNA should provide a rich source of molecular variation in the human genome and should contribute to the development of centromere-based genetic linkage maps of human chromosomes.
Journal Article•
TL;DR: An examination of the different combinations of two or more allelic series suggests that some alleles are not randomly distributed and raises the possibility of establishing a genealogy of the human Y chromosome.
Abstract: We have characterized a DNA probe (49f) that detects about 15 Y-specific TaqI bands corresponding to a low-copy number sequence. Five of these bands, each representing a single DNA fragment, can either be present, absent, or variable in length. Familial segregation studies have shown that the variations of these fragments are inherited in a Mendelian fashion and strictly Y-linked. A survey of 44 male individuals indicated that the five variable TaqI fragments detected by probe 49f can be considered as five independent allelic series. Each series represents the different and mutually exclusive allelic forms observed for a single DNA fragment. A total of 16 haplotypes, each defined by a different combination of the various forms of each of these five restriction fragment length polymorphisms, were observed among the 44 scored individuals. These TaqI restriction polymorphisms are not observed with other restriction digests and have therefore been attributed to point mutations. The five polymorphic fragments map to Yq11, a region that does not recombine with the X chromosome and are therefore not redistributed. This implies that an apparently independent reassortment of one of these series with respect to the others can be explained only on the basis of mutations that occurred several times (or reverted) during evolution of the Y chromosome. However, an examination of the different combinations of two or more allelic series suggests that some alleles are not randomly distributed and raises the possibility of establishing a genealogy of the human Y chromosome.
TL;DR: The most common patients with chronic myeloid leukaemia (CML) have a characteristic deletion of a portion of the long arm of one chromosome 22, the Philadelphia (Ph 1) chromosome as discussed by the authors.
TL;DR: It is suggested that karyotypic evolution has occurred but does not appear to be associated with speciation in this group of Tilapiine species.
Abstract: Seven Tilapiine species from three generaTilapia, Sarotherodon, andOreochromis were cytogenetically studied for chromosome number, chromosome morphology, and DNA content. The chromosome number 2n=44 was the same in all seven species. Arm number (NF) differences indicate the possible role of pericentric invasions in the karyotypic evolution of these species. C-banding of metaphase chromosomes shows that heterochromatin is localised around the centromere in all species ofOreochromis and Sarotherodon butT. zillii has more heterochromatin with six chromosomes having completely C-positive short arms. DNA values vary between 0.84 pq forO. macrochir and 1.21 pq forO. aureus. No heteromorphic sex chromosome pair could be found in any species. These findings suggest that karyotypic evolution has occurred but does not appear to be associated with speciation in this group.
TL;DR: Two DNA sequences that reduce mitotic fidelity of chromosome transmission have been identified: MIF1 and MIF2.
TL;DR: It is found that several genes exist on the B chromosome which help maintain its presence in populations through a system of non‐Mendelian inheritance and a number of methods have been developed for manipulating A chromosome dosage with B‐A translocations.
Abstract: The B chromosome in maize is small and highly heterochromatic. Its presence or absence in a plant has no apparent effect on the organism and the B is considered genetically inert. Studies with the maize B chromosome can be divided into two general categories: (1) analysis of the chromosome itself, including its origin, evolution, gene constitution, and DNA content, and (2) utilization of the chromosome in translocations to manipulate segments of standard (A) chromosomes. In the first category, an important finding has been that several genes exist on the B chromosome which help maintain its presence in populations through a system of non‐Mendelian inheritance. In the second type of research, a number of methods have been developed for manipulating A chromosome dosage with B‐A translocations. Segmental monosomics, trisomics, and tetrasomics have been constructed. Applications of the techniques are found mainly in cytological localization of genes and in construction of gene dosage series.
TL;DR: The location of the deletions suggests that some mechanism maintains the chromosomal breakpoint on the Philadelphia chromosome within a limited region, and complicate the interpretation of Southern blots as a means of detecting the translocation.
TL;DR: Multidrug resistance in several human cell lines correlates with amplification or increased expression of two related DNA sequences, designated mdr1and mdr2, which were used as probes for hybridization with DNA with a panel of human-mouse somatic cell hybrids and from individual human chromosomes separated by fluorescence-activated chromosome sorting.
Abstract: Multidrug resistance in several human cell lines correlates with amplification or increased expression of two related DNA sequences, designated mdr1 and mdr2. These DNA sequences were used as probes for hybridization with DNA with a panel of human-mouse somatic cell hybrids and from individual human chromosomes separated by fluorescence-activated chromosome sorting. By these assays, both mdr1 and mdr2 sequences were localized to chromosome 7.
TL;DR: DNA restriction fragments containing sequences homologous to the ribosomal RNA (45s), the major chlorophyll a/b binding polypeptide (CAB) and the small subunit of ribulose bisphosphate carboxylase (RBCS) genes have been localized and mapped in the tomato nuclear genome by linkage analysis.
Abstract: DNA restriction fragments containing sequences homologous to the ribosomal RNA (45s), the major chlorophyll a/b binding polypeptide (CAB) and the small subunit of ribulose bisphosphate carboxylase (RBCS) genes have been localized and mapped in the tomato nuclear genome by linkage analysis. Ribosomal RNA genes map to a single locus, R45s, which resides in a terminal position on the short arm of chromosome 2 and corresponds to the Nucleolar Organizer Region. The size of the 45s repeating unit is estimated to be approximately 9 kb in Lycopersicon esculentum and 11 kb in Lycopersicon pennellii. Five loci were found to contain CAB sequences. Two of the loci, Cab-1 (chromosome 2) and Cab-3 (chromosome 8), together accounted for more than 80% of the hybridization signal. These loci contain more than one CAB structural gene. The other three loci, Cab-2 (chromosome 8), Cab-4 (chromosome 7) and Cab-5 (chromosome 12), each account for 80% of the signal, with the remainder being associated with Rbcs-1 (chromosome 2). Rbcs-2 and Rbcs-3 may contain more than one copy of the gene.
TL;DR: The breakpoint regions of both translocation products of the (9;22) Philadelphia translocation of CML patient 83-H84 and their normal chromosome 9 and 22 counterparts have been cloned and analysed, strengthening the hypothesis that Alu-repetitive sequences can be hot spots for recombination.
Abstract: The breakpoint regions of both translocation products of the (9;22) Philadelphia translocation of CML patient 83-H84 and their normal chromosome 9 and 22 counterparts have been cloned and analysed. Southern blotting with bcr probes and DNA sequencing revealed that the breaks on chromosome 22 occurred 3' of bcr exon b3 and that the 88 nucleotides between the breakpoints in the chromosome 22 bcr region were deleted. Besides this small deletion of chromosome 22 sequences a large deletion of chromosome 9 sequences (greater than 70 kb) was observed. The chromosome 9 sequences remaining on the 9q+ chromosome (9q+ breakpoint) are located at least 100 kb upstream of the v-abl homologous c-abl exons whereas the translocated chromosome 9 sequences (22q-breakpoint) could be mapped 30 kb upstream of these c-abl sequences. The breakpoints were situated in Alu-repetitive sequences either on chromosome 22 or on chromosome 9, strengthening the hypothesis that Alu-repetitive sequences can be hot spots for recombination.
TL;DR: It is concluded that S. carlsbergensis harbors two structurally different chromosomes V; one being homologous and one homoeologous to the S. cerevisiae chromosome, and disjunction at meiosis appears normal, as indicated by high spore viability.
Abstract: Chromosome V of the Saccharomyces carlsbergensis lager yeast strain 244, a yeast not amenable to tetrad analysis, was analysed genetically in S. cerevisiae genetic standard strains. This was achieved by crossing meiotic progeny of the lager yeast with S. cerevisiae strains carryingkar1 as well as the chromosome V markerscan1, ura3, his1, ilv1, andrad3. From the transitory heterokaryons formed we selected strains retaining the characteristics of the recipient strain but having become prototrophic for uracil, histidine, and isoleucine. The resulting strains were disomic for chromosome V, having acquired a chromosome V from S. carlsbergensis in addition to the normal S. cerevisiae chromosome complement (chromosome addition strains). They were of two classes: In one class the transferred chromosome hardly recombines with the S. cerevisiae chromosome V in the regionCAN1-RAD3, which covers almost the entire known map. In the other class, the transferred chromosome recombined at normal levels. We conclude that S. carlsbergensis harbors two structurally different chromosomes V; one being homologous and one homoeologous to the S. cerevisiae chromosome. By use of theCAN1 locus, strains were selected which by mitotic chromosome loss had their normal chromosome V substituted by either the homologous or the homoeologous S. carlsbergensis chromosome, showing that these chromosomes are fully functional in S. cerevisiae. Tetrad analysis of the chromosome substitution strains confirmed the very different genetic behavior of the two S. carlsbergensis chromosomes V. In spite of the almost complete absence of recombination between the homoeologous chromosome and the S. cerevisiae chromosome, disjunction at meiosis appears normal, as indicated by high spore viability. Genomic Southern hybridizations with the probesCAN1, URA3, CYC7, andILV1 could not detect any nucleotide sequence differences between these loci on the recombining S. carlsbergensis chromosome and the S. cerevisiae alleles. Under standard stringency (68°C, 0.1×SSC), hybridization of the probes to DNA from the strain with the homoeologous chromosome was only observed in the case ofILV1, where weak hybridization was found, indicating a considerable difference in nucleotide sequence. To further study the extent of nucleotide sequence inhomology, the two differentILV1 genes of S. carlsbergensis were cloned in λ vectors. Mapping of 16 restriction enzyme sites showed identity between the allele located on the recombining chromosome and theILV1 gene of S. cerevisiae. The nucleotide sequence of theILV1 gene of the non-recombining chromosome was by restriction site mapping found to be very different from that of the S. cerevisiae allele.
Journal Article•
TL;DR: A panel of Chinese hamster X human somatic cell hybrids, each containing various portions of chromosome 21 as the only detectable human chromosome component, is used for regional mapping of cloned, chromosome 21-derived DNA sequences.
Abstract: We have used a panel of Chinese hamster X human somatic cell hybrids, each containing various portions of chromosome 21 as the only detectable human chromosome component, for regional mapping of cloned, chromosome 21-derived DNA sequences. Thirty unique and very low-repeat sequences were mapped to the short arm and three sections of the long arm. Three unique sequences map to the proximal part of the terminal band 21q22.3, and five to the distal part of this band. Some of these may represent parts of gene sequences that may be relevant to the pathogenesis of Down syndrome, as 21q22 is the area required to be present in triplicate for the full clinical picture.
TL;DR: The previously unassigned gene coding for the anticoagulatory protein C has been mapped on chromosome 2 using a cDNA probe and genomic blots from a human-hamster somatic cell hybrid panel.
Abstract: The previously unassigned gene coding for the anticoagulatory protein C has been mapped on chromosome 2 using a cDNA probe and genomic blots from a human-hamster somatic cell hybrid panel. The assignments of the genes coding for the coagulation factor X to chromosome 13, and for α1-acid glycoprotein to chromosome 9 have been confirmed using a similar direct approach.
TL;DR: The c-ros gene joins the c-myb oncogene, which is distal to the c -ros gene on the long arm of human chromosome 6, as a candidate for involvement in chromosome 6q deletions and rearrangements seen in various malignancies.
Abstract: The human homolog, c-ros, of the transforming gene, v-ros, of the avian sarcoma virus, UR2, has been isolated from a human genomic library A single-copy fragment from the human c-ros genomic clone has been used to map the human c-ros homolog (ROS) to human chromosome region 6q16----6q22 by somatic cell hybrid analysis and chromosomal in situ hybridization Thus, the c-ros gene joins the c-myb oncogene, which is distal to the c-ros gene on the long arm of human chromosome 6, as a candidate for involvement in chromosome 6q deletions and rearrangements seen in various malignancies