Showing papers on "Chromosome 22 published in 1975"
TL;DR: This CML cell-line represents a unique source of CML cells with meaningful indicators of malignancy for clinical and experimental studies.
2,774 citations
TL;DR: In the coccid insects, imprinting occurs in the egg, at the time of fertilisation; it probably occurs at the same time and site in mammals, and possibly also in Sciara.
Abstract: Chromosome imprinting is the process by which one of two genetically homologous chromosomes is predetermined to function differently from the other at a subsequent stage in development. In the coccid insects, imprinting occurs in the egg, at the time of fertilisation; it probably occurs at the same time and site in mammals, and possibly also in Sciara.
100 citations
TL;DR: In order to define more precisely the most proximal portion of chromosome 3R in Drosophila melanogaster, several new chromosome aberrations involving this region have been recovered and analyzed and confirmed the efficacy of this type of screen in the analysis of specific chromosome regions.
Abstract: In order to define more precisely the most proximal portion of chromosome 3R in Drosophila melanogaster , several new chromosome aberrations involving this region have been recovered and analyzed. These new arrangements were recovered as induced reversions of two dominant mutations, Antp Ns and dsx D , located in the region of interest. The results of the analysis have allowed the localization of several existing mutations, have further elucidated the complex homoeotic locus which resides in this region, and have confirmed the efficacy of this type of screen in the analysis of specific chromosome regions.
88 citations
TL;DR: There is diversity among the human, gorilla and chimpanzee in both the size and location of concentrations of 5 MeC, supporting the idea that satellite DNA evolves more rapidly than DNA in the remainder of the chromosome.
Abstract: Fixed metaphase chromosomes of gorilla and chimpanzee were UV-irradiated to produce regions of single-stranded DNA and then treated with antibodies specific for the minor DNA base 5-methylcytosine (5 MeC). An indirect immunofluorescence technique was used to visualize sites of antibody binding. In the gorilla six pairs of autosomes contained major fluorescent regions, indicating localized regions of highly methylated DNA. These corresponded, with the exception of chromosome 19, to the major regions of constitutive heterochromatin as seen by C-banding. The Y chromosome also contained a highly fluorescent region which was located just proximal to the intense Q-band region. In the chimpanzee no comparable concentrations of highly methylated DNA were seen. Smaller regions of intense 5 MeC binding were present on perhaps six chimpanzee chromosomes, including the Y. Five of these corresponded to chromosomes which were highly methylated in the gorilla.--There is diversity among the human, gorilla and chimpanzee in both the size and location of concentrations of 5 MeC, supporting the idea that satellite DNA evolves more rapidly than DNA in the remainder of the chromosome.
65 citations
TL;DR: In this paper, the results of a parallel routine and fluorescent investigation of chromosomes in 103 normal individuals (51 women and 52 men) are presented There were no gross chromosomal abnormalities in the individuals studied, but in 30 (291%) of them various autosomal variants (1q+, 9q+, 16q+, 17ph+, Dp+, Gp+, et al).
Abstract: In the article the results of a parallel routine and fluorescent investigation of chromosomes in 103 normal individuals (51 women and 52 men) are presented There were no gross chromosomal abnormalities in the individuals studied, but in 30 (291%) of them various autosomal variants (1q+, 9q+, 16q+, 17ph+, Dp+, Gp+, et al) were detected by the routine method Five men (95%) had Y chromosome variants The authors were successful in identifyng practically all these chromosomal variant by their fluorescent banding patterns The occurrence of brilliant fluorescent bands in chromosome parts showing variable fluorescence (paracentromeric area of chromosome 3, short arms and satellites of acrocentric chromosomes and the distal part of Y chromosome) was also investigated Some questions connected with karyotype polymorphism in man are discussed
51 citations
TL;DR: A new staining method reveals clearly differentiated bipartite meiotic kinetochores in Ophrys, and Evolutionary aspects of homogamic hybridization, chromosome instability, and of the basic chromosome number x = 18 are discussed.
Abstract: The diploid basic chromosome number forOphrys is 2n = 36. Tetraploidy has been found inO. fusca agg. only. Aneuploidy and aneusomaty are wide-spread; supernumerary chromosomes behave B-like, but do not differ by shape or structure from A-chromosomes. A new staining method reveals clearly differentiated bipartite meiotic kinetochores. Evolutionary aspects of homogamic hybridization, chromosome instability, and of the basic chromosome number x = 18 are discussed.
43 citations
TL;DR: It was concluded that meningioma cells, in contrast to CML and BL, show almost regularly a loss of a definitive part of their genome.
Abstract: The recently detected reciprocal translocations in chronic myeloic leucemia (CML) and Burkitt's lymphoma (BL) made it necessary to clarify if meningiomas really show the described monosomy 22 or also a translocation. In 10 out of 12 meningiomas a total or partial translocation of the missing chromosome 22 to another chromosome could be ruled out by fluorescence banding analysis. Two meningiomas showed marker chromosomes of such a complex composition that it was impossible to decide if a 22 translocation was present or not. From these results it was concluded that meningioma cells, in contrast to CML and BL, show almost regularly a loss of a definitive part of their genome.
31 citations
TL;DR: Since the expression of the transformed phenotype was always associated with the presence of the human chromosome 7, which carries the SV40 genome, it is concluded that this chromosome contains gene(s) coding for "transforming factor(s)."
Abstract: Somatic cell hybrid clones between either C57BL/6 or Balb/c mouse peritoneal macrophages and two different simian virus 40 (SV40)-transformed human cell lines deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase) were obtained in hypoxanthine-aminopterin-thymidine selective medium. All the hybrid cell clones contained the human chromosome 7, which carries the SV40 genome, and were SV40 tumor (T)-antigen positive. No hybrid cell clones studied displayed the density-dependent inhibition of cell growth characteristic of normal cells; all clones had a high saturation density and gave origin to cell colonies when plated in soft agar. Since the expression of the transformed phenotype was always associated with the presence of the human chromosome 7, which carries the SV40 genome, it is concluded that this chromosome contains gene(s) [Tr gene(s)] coding for "transforming factor(s)."
29 citations
Journal Article•
TL;DR: In 6 out of 24 meningiomas of male origin, the chromosomal morphology and association pattern strongly indicated that besides the loss of a chromosome 22, the Y chromosome was also missing, which could be ascertained in 4 tumors by the conspicuous absence of Y fluorescence in interphase nuclei and in metaphase plates after fluorescence staining.
Abstract: Twelve out of 88 cytogenetically examined meningiomas of female patients showed, in addition to the typical loss of a chromosome 22, a loss of 1 or more chromosomes of group C. Among them 8 tumors had less than 8% cells with Barr-body-like particles, whereas in one tumor 12% and in 3 others over 20% Barr bodies were found, which, based on control studies, were classified as sex-chromatin negative, partly positive, and positive, respectively. In one case the loss of an X chromosome was verified by Giemsa banding. In 6 out of 24 meningiomas of male origin, the chromosomal morphology and association pattern strongly indicated that besides the loss of a chromosome 22, the Y chromosome was also missing. Moreover, the loss of the male sex chromosome could be ascertained in 4 tumors by the conspicuous absence of Y fluorescence in interphase nuclei and in metaphase plates after fluorescence staining. The findings are discussed in connection with the gonosomal loss in other human tumors and in old age.
20 citations
TL;DR: The major site of genes for human 5S RNA is in the long arm of chromosome 1, and there is no evidence of sites in other chromosomes; if such exist, they are much smaller than the site in 1q.
Abstract: The major site of genes for human 5S RNA is in the long arm of chromosome 1. We find no evidence of sites in other chromosomes; if such exist, they are much smaller than the site in 1q.
15 citations
TL;DR: None of the 17 patients showed unusual inheritance of HL-A or any other of the polymorphic systems examined, providing evidence excluding the HL- A and other loci from a number of possible locations in the human genome.
Abstract: 17 chromosomally unbalanced patients, their siblings and parents were tested for HL-A types and for up to 25 other polymorphic systems to determine whether there was gain or loss of an allele concurrent with the gain or loss of chromosome material. 5 patients had trisomy of part or all of a chromosome; 2 had trisomy of a segment and also deletion of chromosome material. All 7 were due to a familial translocation. The remaining patients had small deletions; 5 had ring chromosomes, 4 had rod deletions and 1 had missing chromosome material due to a heritable translocation. All cases were informative at the HL-A loci because of the high degree of polymorphism of the system whereas only some of the other systems were informative. None of the 17 patients showed unusual inheritance of HL-A or any other of the polymorphic systems examined. These results provide evidence excluding the HL-A and other loci from a number of possible locations in the human genome.
TL;DR: It was revealed that electrophoretically isolated 5 S RNA hybridized in situ with two adjacent bands in the region 2A, and in heterozygotes harbouring one normal chromosome II and one with the inversion 1A/9C, there is a close physical contact between the bands containing the5 S RNA genes and the nucleolar organizer region.
Abstract: It has earlier been shown by in situ hybridization that the 5 S RNA genes are located in region 2A of chromosome II in chironomus tentans [1]. In the present study the resolution in this chromosome region could be considerably improved by using the inversion 1A/9C of chromosome II, which carries region 2A, not in the usual position close to one end of chromosome II, but in the middle of the chromosome. It was then revealed that electrophoretically isolated 5 S RNA hybridized in situ with two adjacent bands in the region 2A. It was also observed that in heterozygotes harbouring one normal chromosome II and one with the inversion 1A/9C, there is a close physical contact between the bands containing the 5 S RNA genes and the nucleolar organizer region.
Journal Article•
TL;DR: The chromosomes of an SV40-transformed mouse cell line, SVT2, were analyzed by the acetic-saline-Giemsa banding technique to illustrate the advantages of cells of defined chromosome constitution, like STV2 cells and derived sublines, to study specific interactions between transforming virus and host chromosomes.
Abstract: The chromosomes of an SV40-transformed mouse cell line, SVT2, were analyzed by the acetic-saline-Giemsa banding technique. By contrast to most established mouse lines, SVT2 cells possess a remarkably homogeneous chromosome complement and contain two copies of most chromosomes. However, trisomy for chromosome 3 is a distinct feature of this cell line. Chromosomes 1, 3, 14, and 19 have given rise to biarmed markers.
Two Cytochalasin B-resistant sublines derived from SVT2 are also essentially diploid for all autosomes but contain only one chromosome X; they display an even greater homogeneity than does the SVT2 parental cell line. Each of the Cytochalasin B-resistant cell lines has lost one or several of the biarmed markers from SVT2 and new ones have appeared. Both cell lines have lost one copy of chromosome 3 and one chromosome X.
The results presented illustrate the advantages of cells of defined chromosome constitution, like STV2 cells and derived sublines, to study specific interactions between transforming virus and host chromosomes. The possible role of SV40 in the maintenance of the pseudodiploid karyotype of SVT2 is also discussed.
TL;DR: Some cells in this species appear to have an X chromosome of which the facultative heteropycnotic segment condenses in one cell cycle but becomes euchromatic in the subsequent cell cycle, which appears at first to be inconsistent with the generally accepted pattern of X-chromosome condensation and genetic inactivation.
Abstract: The X chromosomes of the female bandicoot rat (Nesokia indica ) were 3H-thymidine labeled during two consecutive cell divisions to determine if all of the same segments of
TL;DR: The results show that inactivation of an X chromosome in vitro, in cells with more than one originally active X chromosome does not occur even after a culture duration of several years.
Abstract: The late replication pattern of the short arms of the X chromosomes of Microtus agrestis was studied in female cells and in cells with 2 X chromosomes of male origin by means of the BUdR-Giemsa technique and of 3H-thymidine labelling. The light absorption of Giemsa stained chromosome sections which were unifilarly substituted with BUdR (labelled), was found to be 59.2% of that of unlabelled chromosomes. In female cells, asynchrony of DNA replication of both X chromosomes indicated the presence of facultative heterochromatin in the X2 and euchromatin in the X1. In the male cells only euchromatic X chromosomes were observed in diploid XX and XO cells as well as in triploid XXY, XX and XO cells. The results show that inactivation of an X chromosome in vitro, in cells with more than one originally active X chromosome does not occur even after a culture duration of several years.
TL;DR: A case of pronounced secondary constriction of a chromosome belonging to pair No. 9, a case of deletion of the short arms of one of the chromosomes in pairs No. 13, and a partial trisomy of the distal portion of a chromosomes in pair No 14 were discovered by prenatal chromosome determination as mentioned in this paper.
Abstract: A case of pronounced secondary constriction of a chromosome belonging to pair No. 9, a case of deletion of the short arms of one of the chromosomes in pair No. 13, and a case of partial trisomy of the distal portion of a chromosome in pair No. 14 were discovered by prenatal chromosome determination. Analysis of the parents' karyotypes enabled the clinical importance of the three different chromosomal aberrations to be elucidated.
TL;DR: The resulting interpretation favours the hypotheses of deletion of the short arm extending into the centromere, based on concordant cytogenetic, clinical and dermatoglyphic findings.
Abstract: A case of "G2 Deletion Syndrome" is reported, based on concordant cytogenetic, clinical and dermatoglyphic findings. The definition if the syndrome, as associated with either a ring or a partially deleted chromosome 22, is discussed. The resulting interpretation favours the hypotheses of deletion of the short arm extending into the centromere.