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Showing papers on "Chromosome 22 published in 1977"


Journal ArticleDOI
TL;DR: Correlation with phenotype and other known Y chromosome markers establish that the Y-chromosome-specific reiterated DNA discussed here has no evident role in male determination.
Abstract: A number of individuals with aberrant Y chromosomes have been tested for the presence of Y-chromosome-specific reiterated DNA. These studies locate Y-chromosome-specific reiterated sequences on the long arm of the Y chromosome. Correlation with phenotype and other known Y chromosome markers establish that the Y-chromosome-specific reiterated DNA discussed here has no evident role in male determination.

1,206 citations


Journal ArticleDOI
01 Sep 1977-Cell
TL;DR: These studies establish the localization of the human α-globin gene to chromosome 16 and represent the first assignment of a nonexpressed unique gene by direct detection of its DNA sequences in somatic cell hybrids.

230 citations


Journal ArticleDOI
TL;DR: If one of the effects of carcinogens is to activate genes that regulate host cell DNA synthesis, and if translocations or duplications of specific chromosomal segments produce the same effect, then either of these mechanisms might provide the affected cell with a proliferative advantage.
Abstract: In clonal aberrations leading to an excess or partial excess of chromosome 1, trisomy for bands 1q25-1q32 was noted in the myeloid cells from all of 34 patients who had various disorders such as acute leukemia, polycythemia vera, and myelofibrosis. This was not the result of a particularly fragile site in that region of the chromosome because the break points in reciprocal translocations that involve it occurred almost exclusively in the short arm. Two consistent rearrangements that have been observed in chromosome 17 produced either duplication of the entire long arm or a translocation of the distal portion of the long arm to chromosome 15. The nonrandom chromosomal changes found in hematologic disorders can now be correlated with the gene loci on these chromosomes or chromosomal segments. Seventy-five genes related to various metabolic enzymes have been mapped; it may be significant that chromosomes carrying gene loci related to nucleic acid metabolism are more frequently involved in hematologic disorders (and other malignancies as well) than are gene loci related to intermediary or carbohydrate metabolism. Furthermore, the known virus-human chromosome associations are closely correlated with the chromosomes affected in hematologic disorders. If one of the effects of carcinogens (including viruses) is to activate genes that regulate host cell DNA synthesis, and if translocations or duplications of specific chromosomal segments produce the same effect, then either of these mechanisms might provide the affected cell with a proliferative advantage.

212 citations


Journal ArticleDOI
18 Nov 1977-Science
TL;DR: Four human neuroblastoma cell lines were studied by chromosome banding techniques and the presence of two additional chromosomal markers in all cells of this line indicates a common origin, suggesting that the double minute chromosomes are derived from the HSR.
Abstract: Four human neuroblastoma cell lines were studied by chromosome banding techniques. All of the lines contained a marker chromosome with a long nonbanding homogeneously staining region (HSR). The HSR-containing chromosome differed in each line. One line contained two classes of cells: one with an HST marker chromosome and the other with double minute chromosomes. Each cell had one of these abnormalities; no cell had both. The presence of two additional chromosomal markers in all cells of this line indicates a common origin. These observations suggest that the double minute chromosomes are derived from the HSR.

176 citations


Journal ArticleDOI
TL;DR: Quantitative correlation between the density of HLA antigens on the hybrid cell surface and the number of copies of the respective HLA gene-bearing chromosome suggests a gene dose effect for cell surface molecules, as it exists for intracellular gene products.
Abstract: Interspecific cell hybrids containing defined parts of human chromosome 6 were used for regional mapping of gene loci previously assigned to chromosome 6: the human leukocyte antigens (HLA) region, phosphoglucomutase-3 (PGM3; alpha-D-glucose-1,6-bisphosphate:alpha-D-glucose-1-phosphate phosphotransferase, EC 2751) and malic enzyme-1 [malic dehydrogenase(decarboxylating) (NADP+), L-malate:NADP+ oxidoreductase (oxaloacetate-decarboxylating), EC 11140] Human fibroblasts containing a balanced reciprocal translocation between the short arms of chromosome 1 and chromosome 6--designated t(1;6) (p3200;p2100)--were fused with an established line of Chinese hamster cells Hybrid clones with segregating human chromosomes were studied for the presence of the translocation chromosomes 1T and 6T and their normal homologues 1 and 6 Six clones that had retained 1T, three clones with 6T, and three clones with 6 and 6T as controls, were analyzed by a microabsorption test for expression of the allelic antigens HLA-A2 and HLA-A3, both of which were present on the human parental cells HLA-A2 segregated with the 1T translocation chromosome and HLA-A3 with the normal chromosome 6 Hybrid clones with 6T did not possess an HLA-A gene In contrast, human PGM3 and malic enzyme-1 expression segregated with the 6T translocation chromosome These results indicate the location of the major histocompatibility complex in region 6p2100 leads to 6pter of the short arm of chromosome 6 The genes for PGM2 and malic enzyme-1 map in region 6p2100 leads to 6qter The HLA:PGM3 genetic map distance is 15 centimorgans in males, as established by family studies This allows rather precise mapping of both loci because HLA is distal and PGM3 proximal to the translocation breakpoint in band 6p2100 The findings are consistent with earlier conclusions that HLA is proximal to 6p22 Quantitative correlation between the density of HLA antigens on the hybrid cell surface and the number of copies of the respective HLA gene-bearing chromosome suggests a gene dose effect for cell surface molecules, as it exists for intracellular gene products

143 citations


Journal Article
TL;DR: Regression analysis of the 50 acrocentric chromosomes which could be individually identified by quinacrine markers showed that the frequency with which a chromosome was involved in satellite association was strongly correlated with the amount of Ag-stained material in the NOR.
Abstract: Methaphase chromosomes from karyotypically normal adult humans (three males, six females) and one male with a 13p - chromosome were stained by quinacrine and then by the Ag-AS silver staining method to reveal nucleolus organizer regions (NORs). Each person had a characteristic number of Ag-stained chromosomes per cell, always fewer than 10. Determination of the mean Ag-size of each chromosome showed that each of the 10 individuals had a unique distribution of Ag-stain. Within each individual, there was some variation from cell to cell in the number of acrocentric chromosomes that were Ag-stained; this was not random, and the same chromosomes (those that had at most a small amount of Ag-stain) tended to be unstained in every cell. Satellite associations were scored on the same cells. Chromosomes that had no Ag-stain were involved in satellite association less than 20% as often as those that had some Ag-stain. Chromosomes that had a small amount of Ag-stain were involved in association about 50% as often as those that had a large amount of stain. Regression analysis of the 50 (of a total of 100) acrocentric chromosomes which could be individually identified by quinacrine markers showed that the frequency with which a chromosome was involved in satellite association was strongly correlated with the amount of Ag-stained material in the NOR.

140 citations


Journal ArticleDOI
TL;DR: The cytologic studies provide a comparison between data from sexual genetics and somatic cell hybrids and validate hybrid cell techniques and provide evidence of the reliability of scoring chromosomes by GTG and Hoechst staining and stress the importance of identifying clones with multiple chromosome rearrangements.
Abstract: Chinese hamster X mouse somatic cell hybrids segregating mouse chromosomes were examined for their mouse chromosome content using trypsin-Giemsa (GTG) banding and Hoechst 33258 staining techniques. Si

121 citations


Journal ArticleDOI
02 Dec 1977-Science
TL;DR: The H-Y locus is on the short arm of the human Y chromosome in most individuals but on the long arm in at least one of 17 individuals with structural abnormalities of the Y.
Abstract: The H-Y locus is on the short arm of the human Y chromosome in most individuals but on the long arm in at least one of 17 individuals with structural abnormalities of the Y.

113 citations


Journal ArticleDOI
TL;DR: The marked binding of antibodies specific for 5-methylcytidine to the short arm of chromosome 15 distinguishes this chromosome from the other human acrocentrics.
Abstract: The marked binding of antibodies specific for 5-methylcytidine to the short arm of chromosome 15 distinguishes this chromosome from the other human acrocentrics. This method has been used to study over 60 individuals including 12 who did not have Down's syndrome, but who did have an extra G-group sized acrocentric chromosome. In six cases the extra chromosome did not show intensive binding of anti-5-methylcytidine. In the other six cases, the extra chromosome contained a 5-methylcytidine rich band at each end indicating that both ends were derived from chromosome 15 and contained centromeric heterochromatin normally present on the short arm of chromosome 15. The duplication of short arm material in the abnormal chromosomes was confirmed in all cases by quinacrine staining, nucleolar organizer (Ag-AS) staining or C-banding. In three cases, the abnormal chromosome appeared to arise from two different chromosomes 15. Several possible mechanisms for the production of the abnormal chromosome are discussed. The individuals with this abnormal chromosome all showed some degree of mental retardation, but few common physical findings.

101 citations


Journal ArticleDOI
TL;DR: 4 patients with inverted tandem duplications of parts of chromosomes, a hitherto rarely identified form of a structural rearrangement involving a single chromosome in man, involved different chromosomal regions and might well have arisen by the same mechanism.
Abstract: We have studied 4 patients with inverted tandem duplications of parts of chromosomes, a hitherto rarely identified form of a structural rearrangement involving a single chromosome in man. In patients 1 and 2, the duplication involved parts of the short arm of chromosome 8 (regions 8p12 leads to 8p23 and 8p21 leads to 8p23, respectively). Both patients manifested certain characteristics of the mosaic trisomy 8 syndrome. Elevated levels of glutathione reductase (GSR) in their erythrocytes supported the interpretation of a partial duplication of chromosome 8 and indicated a regional localization for the GSR gene locus. In Partient 3, the distal half of the long arm of chromosome 4 was duplicated (region 4q23 leads to 4q35). Clinical evidence supported this interpretation, as Patient 3 resembled phenotypically the 13 reported cases with duplication of the distal 4q. The cytogenetic findings in Patient 4 suggested a possibly inverted duplication of 22q. The clinical correlation was less convincing due to the lack of a well-defined phenotype for trisomy 22. These chromosome aberrations had occurred de novo in all 4 cases. Although they involved different chromosomal regions, they might well have arisen by the same mechanism. Possible modes of origin that are discussed in detail include unequal exchange between homologous chromosomes, between chromatids of 1 chromosome or between strands of 1 DNA duplex.

94 citations


Journal ArticleDOI
01 Oct 1977-Blood
TL;DR: In this paper, the authors evaluated the clinical, prognostic, and survival picture in 30 known cases of chronic myelocytic leukemia (CML) with unusual or complex Ph 1 translocations.

Journal ArticleDOI
TL;DR: A comparison of the statistical maps of chromosome I and of the X-chromosome with the cytogenetic maps of these chromosomes at metaphase indicates that the statistically derived distances between genes are related to the amount of Giemsa light-band material between the genes.
Abstract: A method is described which should permit determination of the order and spacing of genes on all human chromosomes by the analysis of just one set of man-mouse hybrid cells. This method is used to determine the map of 8 loci on human chromosome I. A comparison of the statistical maps of chromosome I and of the X-chromosome with the cytogenetic maps of these chromosomes at metaphase indicates that the statistically derived distances between genes are related to the amount of Giemsa light-band material between the genes.

Journal ArticleDOI
TL;DR: The results provide the first direct evidence for the assignment of the HPRTlocus to the X chromosome in Chinese hamster, and in fact allow mapping of this locus to the distal region of the short arm.
Abstract: The phenomenon of segregation of gene expression has been examined in intraspecific somatic cell hybrids. Specifically, segregation at the hypoxanthine guanine phosphoribosyltransferase (HPRT)locus has been studied in hybrids of Chinese hamster cell lines. The role of chromosome segregation, or other chromosomal events has been assessed by detailed comparison of karyotypes in the 6-thioguanine resistant segregants with those of the parental hybrid lines. The results clearly demonstrate that loss of an entire X chromosome is the primary event responsible for segregation at the HPRTlocus, while deletion of a portion of the short arm of an X chromosome was also a frequent event. The results provide the first direct evidence for the assignment of the HPRTlocus to the X chromosome in Chinese hamster, and in fact allow mapping of this locus to the distal region of the short arm. Analysis of chromosome number distributions in the hybrids and segregants suggests that in selecting chromosomal segregants one may also select for hybrid lines with reduced chromosome stability.

Journal ArticleDOI
TL;DR: In a newborn boy with multiple malformations, a tandem duplication was detected at the distal end of the long arm of one human chromosome 1 and the Giemsa bands, 1q31 to 1q43–44, were repeated serially.
Abstract: In a newborn boy with multiple malformations, a tandem duplication was detected at the distal end of the long arm of one human chromosome 1. The Giemsa bands, 1q31 to 1q43--44, were repeated serially. Since 5S rRNA genes are located at 1q42--43, in situ hybridization of 125I 5S rRNA with fixed chromosome preparations was used to confirm the chromosomal duplication. The infant exhibited numerous developmental and clinical abnormalities as might be expected with an abnormality of chromosome structure relating to a ribosome component.

Journal ArticleDOI
TL;DR: Human/rodent hybrid cell cultures were examined for the presence of 1 and other marker enzymes and complete concordance was found only with chromosome 22.
Abstract: SUMMARY Human/rodent hybrid cell cultures were examined for the presence of 1 and other marker enzymes. Many of these hybrids were also analysed for human chromosomes. Complete concordance was found only with chromosome 22.

Journal ArticleDOI
TL;DR: Chromosome studies of a malignant lymphoma of the brain were made by G-, Q-, and C-banding techniques and by autoradiography, and the application of autoreadiography in addition to banding techniques was stressed as necessary in cytogenetic studies of tumor chromosomes.
Abstract: Chromosome studies of a malignant lymphoma of the brain were made by G-, Q-, and C-banding techniques and by autoradiography. The tumor had a modal chromosome number of 47 and contained 4 markers: 1q-, 6p+, 11q+, and 14q+. A 14q+ marker chromosome frequently seen in malignant lymphomas was identified as a translocation between chromosomes No. 1 and 14 in this case. Although the banding pattern did not reveal abnormalities in chromosomes No. 22, the late replication of one chromosome No. 22 was detected by autoradiography. The abnormality of chromosomes No. 14 and 22 was discussed in relation to its occurrence in brain tumors, and the application of autoradiography in addition to banding techniques was stressed as necessary in cytogenetic studies of tumor chromosomes.

Journal ArticleDOI
TL;DR: Chinese hamster-human somatic cell hybrids were analyzed for the expression of human galactose-1-phosphate uridyltransferase and the correct assignment of the human GALT locus is to chromosome 9.
Abstract: Chinese hamster-human somatic cell hybrids were analyzed for the expression of human galactose-1-phosphate uridyltransferase (GALT; UDPglucose:alpha-D-galactose-1-phosphate uridyltransferase, EC 2.7.7.12) by electrophoresis and for the presence of human chromosomes cytogenetically with the aid of Q-banding. Three of the 10 randomly chosen independently derived primary hybrid lines showed the presence of human GALT. Human chromosome 9 was consistently present in the hybrid lines expressing human GALT and consistently absent in the lines not expressing it. Biochemical analysis alone of 11 independently derived hybrid lines showed human GALT to be syntenic with known chromosome 9 markers (soluble aconitase, adenylate kinase 1, and adenylate kinase 3). Previous studies on chromosome assignment of this locus, utilizing somatic cell hybrids, have yielded inconsistent results; one group assigned GALT to chromosome 2, and another assigned it to chromosome 3. However, we believe that, based on our results and other published evidence, the correct assignment of the human GALT locus is to chromosome 9.

Journal ArticleDOI
TL;DR: The simian virus 40 integration site and the gene coding for human beta-glucuronidase appear to be localized to the long arm of chromosome 7 in this hybrid clone.
Abstract: Immunoselection via complement-dependent lysis of human-mouse somatic cell hybrids containing chromosome 7, with antisera reactive to cell surface antigen(s) coded for by chromosome 7, has resulted in growth of somatic cell hybrids containing rearranged human chromosome 7s. Investigation of these hybrids has localized the gene(s) coding for the relevant cell surface antigen(s) to the short arm of human chromosome 7. The simian virus 40 integration site and the gene coding for human beta-glucuronidase appear to be localized to the long arm of chromosome 7 in this hybrid clone.

Journal ArticleDOI
01 Apr 1977-Genetics
TL;DR: A testable model is proposed suggesting that centromere involvement in genetic recombination may precipitate segregational disfunction leading to mitotic chromosome loss.
Abstract: Experiments designed to characterize the association between disomic chromosome loss and centromere-adjacent mitotic recombination were performed. Mitotic gene convertants were selected at two heteroallelic sites on the left arm of disomic chromosome III and tested for coincident chromosome loss. The principal results are: (1) Disomic chromosome loss is markedly enhanced (nearly 40-fold) over basal levels among mitotic gene convertants selected to arise close to the centromere; no such enhancement is observed among convertants selected to arise relatively far from the centromere. (2) Chromosome loss is primarily associated with proximal allele conversion at the centromere-adjacent site, and many of these convertants are reciprocally recombined in the adjacent proximal interval. (3) Partial aneuploid exceptions provisionally identified as carrying left arm telocentrics have been found. A testable model is proposed suggesting that centromere involvement in genetic recombination may precipitate segregational disfunction leading to mitotic chromosome loss.

Journal ArticleDOI
TL;DR: TheLyb-2 locus responsible for the B-lymphocyte alloantigen system LyB-2 is located on chromosome 4 at a distance of 20.6±4.9 map units fromPgm-2.
Abstract: TheLyb-2 locus responsible for the B-lymphocyte alloantigen system Lyb-2 is located on chromosome 4 at a distance of 20.6±4.9 map units fromPgm-2. A three-point cross indicated the orderLyb-2: Mup-1∶b∶ Pgm-2.

Journal ArticleDOI
TL;DR: In demonstrating that GUS was not assigned to chromosome 9 utilizing an X/9 translocation segregating in cell hybrids, the gene coding for human adenylate kinase1 was confirmed to be located on chromosome 9.
Abstract: β-Glucuronidase (GUS) has become an important enzyme model for the genetic study of molecular disease, enzyme realization, and therapy, and for the biogenesis and function of the lysosome and lysosomal enzymes. The genetics of human β-glucuronidase was investigated utilizing 188 primary man-mouse and man-Chinese hamster somatic cell hybrids segregating human chromosomes. Cell hybrids were derived from 16 different fusion experiments involving cells from ten different and unrelated individuals and six different rodent cell lines. The genetic relationship of GUS to 28 enzyme markers representing 19 linkage groups was determined, and chromosome studies on selected cell hybrids were performed. The evidence indicates that the β-glucuronidase gene is assigned to chromosome 7 in man. Comparative linkage data in man and mouse indicate that the structural gene GUS is located in a region on chromosome 7 that has remained conserved during evolution. Involvement of other chromosomes whose genes may be important in the final expression of GUS was not observed. A tetrameric structure of human β-glucuronidase was demonstrated by the formation of three heteropolymers migrating between the human and mouse molecular forms in chromosome 7 positive cell hybrids. Linkage of GUS to other lysosomal enzyme genes was investigated. β-Hexosaminidase HEX B) was assigned to chromosome 5; acid phosphatase2 (ACP 2) and esterase A4 (ES-A 4) were assigned to chromosome 11; HEX A was not linked to GUS; and α-galactosidase (α-GAL) was localized on the X chromosome. These assignments are consistent with previous reports. Evidence was not obtained for a cluster of lysosomal enzyme structural genes. In demonstrating that GUS was not assigned to chromosome 9 utilizing an X/9 translocation segregating in cell hybrids, the gene coding for human adenylate kinase1 was confirmed to be located on chromosome 9.

Journal ArticleDOI
13 Jan 1977-Nature
TL;DR: Evidence of two euchromatic X chromosomes in about 15% of metaphases from lymphocyte cultures means that in these cells there were two active X chromosomes.
Abstract: IN a female child with various morphological abnormalities and partial translocation trisomy X—haryotype: 46,XX, −22, +der(22),t(X;22)(q12;p11)mat—we have found evidence of two euchromatic X chromosomes in about 15% of metaphases from lymphocyte cultures. We believe this means that in these cells there were two active X chromosomes.

Journal ArticleDOI
TL;DR: Employing RFA (R bands by fluorescence using acridine orange) technique it was clear that the part of the long arm of chromosome 1 was missing and the tip of theLong arm chromosome 22 (band q22) was translocated to it and the whole terminal part was lost.
Abstract: A case of chronic myelogenous leukemia (CML) with complex chromosomal abnormalities is reported. Conventional staining techniques indicated incorrectly that the Ph1 chromosome was not present. These studies showed a 46,XY,-1,+C karyotype in all bone marrow cells. Employing RFA (R bands by fluorescence using acridine orange) technique it was clear that the part of the long arm of chromosome 1 (1q23 leads to qter) was missing the tip of the long arm chromosome 22 (band q22) was translocated to it. The missing long arm of chromosome 1 was translocated to the long arm of chromosome 9. Furthermore, there was a break at band 9q22 and the whole terminal part was lost. The value of RFA technique is discussed.

Journal ArticleDOI
TL;DR: Investigation of man-Chinese hamster hybrid cells provided evidence that a locus for β-galactosidase is situated on chromosome 22 distal to the breakpoint in q13, and showed that these hybrids did contain immunological determinants of human origin.
Abstract: Human white blood cells with an X/22 translocation [46, XX, t(X; 22)(q23; q13)] were fused with Chinese hamster cells. The isolated hybrids were analyzed for human chromosomes and 21 enzyme markers. An electrophoretic technique for studying the β-galactosidase isoenzymes in man-Chinese hamster hybrid cells was developed. Immunological studies showed that the β-galactosidase marker studied in these hybrids did contain immunological determinants of human origin. Furthermore the results provided evidence that a locus for β-galactosidase is situated on chromosome 22 distal to the breakpoint in q13.

Journal ArticleDOI
TL;DR: The large heterochromatic chromosome of Drosophila nasutoides reveals distinctive C- and Q-bands and the locality of the satellite DNAs in this chromosome is discussed.
Abstract: The large heterochromatic chromosome of Drosophila nasutoides reveals distinctive C- and Q-bands. The regions which are negative in C-banding appear positive in Q-banding. The isochromosomic nature of this chromosome and the locality of the satellite DNAs in this chromosome are discussed with respect to these banding patterns.

Journal ArticleDOI
TL;DR: Bone-marrow metaphases in a 63-year-old male with newly discovered chronic myelocytic leukemia showed a complex translocation involving chromosomes 9, 11, and 22, which was typical of CML.
Abstract: Bone-marrow metaphases in a 63-year-old male with newly discovered chronic myelocytic leukemia (CML) showed a complex translocation involving chromosomes 9, 11, and 22. About half of the short arm of chromosome 11 was translocated to the terminal part of the long arm of chromosome 9, and the missing fragment on chromosome 22 was translocated to the short arm of the abnormal chromosome 9. The clinical features were typical of CML, and the patient is in good physical condition 10 months after diagnosis on a regimen of busulfan.

01 Jan 1977
TL;DR: The results suggest that, as in XY2A larval glands, the X chromosome in the XO2A cells also completes the replication earlier than autosomes and that the X O2A nuclei show cellular autonomy with respect to the early replication of the X chromosomes, like its counterpart, RNA transcription.
Abstract: [aH]Thymidine labeling patterns have been examined in gynandric mosaic salivary glands of Drosophila melanogaster. The Ring-X stock, R(1) wVC/In(1)dl 49, l (1) J1 y w lz s, was used for this purpose. 365 labeled XX2A and 40 labeled XO2A nuclei were obtained from a total of 624 nuclei in nine pairs of mosaic salivary glands. It was observed that in all but those nuclei which had DD, 1C, and 2C patterns, the X chromosome of the XO2A nuclei always had fewer sites labeled than the X chromosomes of the XX2A nuclei, for a given pattern of the autosomes in either sex. Such asynchronous labeling of the X chromosome in the XO2A (male) nuclei was observed regardless of the proportion of the XO2A cells (2.0-73.7%), in the mosaic glands. Moreover, while the frequency of [aH]thymidine labeling for all of the 39 replicating units except the two late replicating sites (3C and 11A) in the X chromosome of the XO2A nuclei, was consistently lower than in the X chromosome of the XX2A nuclei, the mean number of grains on the X chromosome was relatively (to autosomes) similar in both XX2A and XO2A cells. The results, therefore, suggest that, as in XY2A larval glands, the X chromosome in the XO2A cells also completes the replication earlier than autosomes and that the XO2A nuclei show cellular autonomy with respect to the early replication of the X chromosome, like its counterpart, RNA transcription. Absence of the asynchrony during the initial phase (DD-2C) further supports the contention (a) that the single X chromosome of the male not only completes the replication earlier but that the rate of replication of its DNA is possibly faster, and (b) that there might be a common regulation with respect to the initiation of replication of different chromosomes in a genome. Mukherjee and Beermann (14) demonstrated that the X chromosome of male Drosophila produces twice as much RNA as the individual X chromosomes of female Drosophila. This hyperactivity of

Journal ArticleDOI
TL;DR: The position of genes coding for PGD, PPH1, UGPP, GuK1, PGM1, Pep-C, and FH on human chromosome 1 was investigated by analysis of karyotype and enzyme phenotypes in man-Chinese hamster somatic cell hybrids carrying aberrations involving chromosome 1.
Abstract: The position of genes coding for PGD, PPH1, UGPP, GuK1 PGM1, Pep-C, and FH on human chromosome 1 was investigated by analysis of karyotype and enzyme phenotypes in man

Journal ArticleDOI
TL;DR: The majority (>90%) of the grains could be blocked by competition with excess repetitive DNA in the hybridization reaction, indicating that the in situ hybridization involved predominantly repetitive sequences.
Abstract: In situ hybridization of complementary DNA (cDNA) synthesized from total cytoplasmic polyadenylated RNA isolated from Chinese hamster cells was employed to investigate the distribution of messenger specifying sequences on mammalian chromosomes. The kinetics of cDNA-nuclear DNA annealing indicate that about 85% of the cDNA represents sequences which are transcribed from non-repetitive DNA sequences. When cDNA is hybridized back to its template RNA, the reaction kinetics show that more than 60% of the poly(A) RNA is at least 104 times more complex than rabbit globin mRNA. In situ hybridization of cDNA to Chinese hamster cells fixed on slides shows no significant clustering of silver grains on interphase nuclei. On metaphase chromosomes the majority of silver grains are localized in euchromatic areas. It appears that all euchromatic segments have similar grain densities. Chromosomes 1 and 2, which have relatively little heterochromatin, do not have a higher grain density than the other chromosomes. However, the Y chromosome, which is entirely heterochromatic, contains only about 1/3 the grain density of the chromosomes 1 or 2. — When the cDNA, which anneals only to the high abundancy class of poly(A) RNA was fractionated and hybridized in situ to Chinese hamster chromosomes, the distribution of silver grains is localized in the euchromatic areas. The Y chromosome and the heterochromatic arm of the X chromosome contain less grains; telomeres of some autosomes have higher grain densities. The oligo-(dT) primer in cDNA did not affect the results of this study since no grains are found when 3H-poly(dT) was used as probe for in situ hybridization. The majority (>90%) of the grains could be blocked by competition with excess repetitive DNA in the hybridization reaction, indicating that the in situ hybridization involved predominantly repetitive sequences.

Journal ArticleDOI
TL;DR: Results provide additional confirmation for the assignment of the tryptophanyl-tRNA synthetase gene to human chromosome 14 and define its intrachromosomal location in the region 14q21 → 14qter.
Abstract: A gene for tryptophanyl-tRNA synthetase (EC 6.1.1.2), the enzyme which attaches tryptophan to its tRNA, has previously been assigned to human chromosome 14 by analysis of man-mouse somatic cell hybrids. We report here a method for the electrophoretic separation of Chinese hamster and human tryptophanyl-tRNA synthetases and its application to a series of independently derived Chinese hamster-human hybrids in which part of the human chromosome 14 has been translocated to the human X chromosome. When this derivative der (X),t(X;14) (Xqter → Xp22::14q21 → 14qter) chromosome carrying the human gene for hypoxanthine-guanine phosphoribosyltransferase was selected for and against in cell hybrid lines by the appropriate selective conditions, the human tryptophanyl-tRNA synthetase activity was found to segregate concordantly. These results provide additional confirmation for the assignment of the tryptophanyl-tRNA synthetase gene to human chromosome 14 and define its intrachromosomal location in the region 14q21 → 14qter. Our findings indicate that the genes for tryptophanyl-tRNA synthetase and for ribosomal RNA are not closely linked on chromosome 14.