bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromosome banding and gene localizations support extensive conservation of chromosome structure between cattle and sheep
Authors: Hediger R. , Ansari H.A. , Stranzinger G.F.
Published: May 2008

By using three gene probes, one derived from the porcine major histocompatibility complex (MHC) and two from bovine cytokeratin genes, type I (KRTA) and type II (KRTB), the hypothesis of conservation of genome structure in two members of the family Bovidae was examined. Gene mapping data revealed the MHC to be in chromosome region 23q15→q23 in cattle (BOLA) and 20q15→q23 in sheep (OLA). KRTA was localized to chromosome region 19q25→q29 in cattle and 11q25→q29 in sheep and KRTB to 5q14→q22 in cattle and 3q14→q22 in sheep. The banding patterns of the chromosome arms to which the loci were assigned were identical in both species. Moreover, the resemblances of GTG- or QFQ-banding patterns between the cattle and sheep karyotypes illustrated further chromosome homologies. These studies, based on gene mapping comparisons and comparative cytogenetics, document that within bovid chromosomes, homology of banding patterns corresponds to a homologous genetic structure. Hence, we propose that gene assignments on identified chromosomal segments in one species of the Bovidae can be extrapolated, in general, to other bovid species based on the banding homologies presented here.
Chromosome studies in the red howler monkey, Alouatta seniculus stramineus (Platyrrhini, Primates): description of an X1X2Y1Y2/X1X1X2X2sex-chromosome system and karyological comparisons with other subspecies
Authors: Lima M.M.C. , Seuánez H.N.
Published: May 2008

In the red howler monkey, Alouatta seniculus stramineus (2n = 47, 48, or 49), variations in diploid chromosome number are due to different numbers of microchromo-somes. Males exhibit a Y autosome translocation involving the short arm of an individual biarmed autosome. Consequently, the sex-chromosome constitution in the male is X1X2Y1Y2with X1 representing the original X chromosome, X2 the biarmed autosome (No. 7), Y1 the Y;7p translocation product, and Y2 the acrocentric homolog of 7q. In the first meiotic division, a quadrivalent with a chain configuration can be observed in spermatocytes. Females have an X1X1X2X2sex-chromosome constitution. Chromosome heteromorphisms were observed in pair 13, due to a pericentric inversion, and pair 19, due to the presence of constitutive heterochromatin. Microchromosomes, which varied in number between individuals, were also heterochromatic. NOR-staining was observed at two separate sites on a single chromosome pair (No. 10). A comparison of A. s. stramineus with A.s. macconnelli shows that these two subspecies have identical diploid chromosome numbers (47, 48, or 49), again due to a varying number of microchromosomes, and that they share a similar sex-chromosome constitution. Their karyotypes, however, are not identical, but can be derived from each other by a reciprocal translocation. Further comparisons with other A. seniculus subspecies reported in the literature indicate that this taxon is not karyologically uniform and that substantial chromosome shuffling has occurred between populations that have been considered to be subspecies by taxonomic criteria based on their morphometric attributes.
Transcribed and nontranscribed parts of the human ribosomal gene repeat show a similar pattern of distribution in nucleoli
Authors: Wachtler F. , Schöfer C. , Schedle A. , Schwarzacher H.G. , Hartung M. , Stahl A. , Gonzales I. , Sylvester J.
Published: May 2008

The distribution pattern of the transcribed and nontranscribed parts of human ribosomal RNA genes were visualized simultaneously in the same cells by nonautoradiographic in situ hybridization. DNA probes labeled with either digoxigenin or biotin were detected in the same cells by different fluorescence systems. The signals from both the transcribed and nontranscribed parts showed a similar distribution pattern. This finding is not compatible with the conclusion, suggested by earlier studies, that the transcribed and nontranscribed parts of the rRNA genes are located at different sites within the nucleoli or in different nucleolar components.
A low-copy repeat located in subtelomeric regions of 14 different human chromosomal termini
Authors: Weber B. , Allen L. , Magenis R.E. , Hayden M.R.
Published: May 2008

Two cosmid clones, cG1A3 and cG1A6, containing large blocks of a telomeric repeat sequence, (TTAGGG)n, were isolated independently. Restriction mapping and fingerprinting studies suggested that cosmid cG1A6 is entirely contained within cG1A3. Competitive in situ hybridization localized cG1A3 to 14 different human telomeres and one internal site at 2q14→q21, indicating the presence of a subtelomeric low-copy repeat within this cosmid.
Chromosomal localization of the human gene for annexin V (placental anticoagulant protein I) to 4q26→q28
Authors: Tait J.F. , Frankenberry D.A. , Shiang R. , Murray J.C. , Adler D.A. , Disteche C.M.
Published: May 2008

Annexin V is a member of a new family of calcium-dependent phospholipid-binding proteins. It has been previously isolated as placental anticoagulant protein I, inhibitor of blood coagulation, vascular anticoagulant-α, endonexin II, lipocortin V, placental protein 4, and anchorin CΠ. The human gene encoding annexin V (ANX5) was localized to 4q26→q28 by in situ hybridization with a cDNA probe and polymerase chain-reaction (PCR) analysis of a human × hamster hybrid cell panel. The regional localization to 4q26→q28 was supported by Southern-blot analysis of a human cell line with a deletion in 4q23→q27. This localization overlaps but differs slightly from the previous assignment of ANX5 to 4q28→q32. Digestion with Pvull and Taql identified polymorphisms at the ANX5 locus; the Pvull polymorphism could also be detected by PCR analysis.
Ribosomal RNA gene site polymorphism in Bufo terrestris
Authors: Foote D.L. , Wiley J.E. , Little M.L. , Meyne J.
Published: May 2008

Individual specimens of Bufo terrestris were discovered that possessed ribosomal gene locations in addition to those normally found. Every specimen from an island population that was examined had extra sites, whereas fewer individuals from coastal mainland populations and none from inland populations had them. Although the extra ribosomal gene locations probably did not arise through gross structural chromosome rearrangements, their origin remains unclear.
Failure of chromosomally abnormal sperm to participate in fertilization in the Chinese hamster
Authors: Sonta S. , Yamada M. , Tsukasaki M.
Published: May 2008

The selection of chromosomally abnormal gametes was investigated in the Chinese hamster by direct chromosome analysis of meiotic cells and one-cell embryos obtained from crossing heterozygotes for two reciprocal translocations, T(1;3)7Idr and T(1;3)8Idr. Expected frequencies of male and female gametes with different chromosome constitutions were estimated by scoring of secondary meiotic metaphase (MII) cells in the translocation heterozygotes. The frequency of gametes with each karyotype that participated in fertilization was investigated in pronuclei from translocation heterozygotes in one-cell embryos obtained from crossing the heterozygotes with karyo typically normal animals. Compared with the expected frequencies from MII scoring, the frequencies of male pronuclei having some karyotypes in one-cell embryos decreased significantly. The karyotypes of male pronuclei showing a decreased frequency were commonly characterized by a deficiency of the long-arm segment of chromosome 1 (q13→qter) or by a deficiency of almost the whole arms of chromosome 3. On the other hand, the frequencies of female pronuclei with the same karyotypes were all consistent with those estimated from MII scoring. These results suggest that sperm nullisomic for certain segments of some chromosomes may fail to participate in fertilization.
Chromosomal localization of the major histocompatibility complex (MHC) in the rhesus monkey and chimpanzee by fluorescence in situ hybridization
Authors: Hirai M. , Takahashi E. , Ishida T. , Hori T.
Published: May 2008

Genes for the major histocompatibility complex (MHC) were localized by fluorescence in situ hybridization to the long arm of rhesus monkey chromosome 5. This localization contradicts previous reports, based on genetic investigation of somatic cell hybrids, that placed the MHC on chromosome 2 of this species. In the chimpanzee, the MHC loci were localized to 5p21.3, corresponding precisely to their location on human chromosome 6p21.3.
Cytological evidence of maternal meiotic errors in a line of chickens with a high incidence of triploidy
Authors: Thorne M.H. , Sheldon B.L.
Published: May 2008

Direct evidence of the nature of maternal meiotic errors in a selected line of chickens with a high incidence of triploidy was obtained by using cytologically marked paternal gametes derived from a closely related avian species. Matings were made by artificial insemination of female chickens of the selection line and a control line with semen from ring-necked male pheasants. A total of five triploid, one pentaploid, and 21 diploid hybrid embryos were karyotyped. Each triploid hybrid embryo contained one set of paternal pheasant chromosomes and two sets of maternal chicken chromosomes, providing irrefutable cytological evidence that the triploids were derived from diploid ova produced by females of the selection line. The pentaploid hybrid contained one set of paternal pheasant chromosomes and four sets of maternal chicken chromosomes, indicating that it had been derived from a tetraploid ovum. Females of the selection line are thought to have a genetically mediated susceptibility to nondisjunction which is responsible for the high incidence of meiotic errors. Evidence is provided that the non-disjunction occurs at both meiosis I and meiosis II.
Über zwei weitere Fälle von autosomaler Trisomie, 61, XY,+12 und 61, XX,+12, beim Rind
Authors: Herzog A. , Hoehn H.
Published: May 2008

Two new cases of trisomy of chromosome No. 12 in cattle are reported. The phenotypic effects of this chromosome aberration are described and discussed.
Mapping of the gene coding for the muscle protein nebulin (Neb) to the proximal region of mouse Chromosome 2
Authors: Schurr E. , Skamene E. , Gros P.
Published: May 2008

Using five different series of recombinant inbred (RI) strains, we have mapped the gene encoding nebulin, a muscle-specific protein. The strain distribution pattern of Neb-specific RFLPs segregating in the RI strains showed significant concordance with those of Pmv-7 and Hc, two loci previously located to proximal mouse Chromosome 2. The gene order, intergene distances, and confidence intervals were determined according to standard maximum likelihood estimates as: centromere-Hc-5.4 cM (1.4 cM-15.4 cM; 95% confidence interval)- Neb-3.6 cM (1.5–6.7 cM)-Pmv-7.
C-band polymorphisms in exotic inbred strains of mice: a method for mapping centromeric ends of chromosomes
Authors: Akeson E.C. , Davisson M.T.
Published: May 2008

The major satellite DNA of Mus musculus appears as a pericentromeric heterochromatin block in all chromosomes but the Y. While C-banding readily reveals the presence of this heterochromatin block, there is considerable polymorphism in C-band size among the chromosomes and among different subspecies. We have studied the distribution of C-band size differ ences in the chromosomes of 15 exotic inbred laboratory strains and substrains derived from wild populations of different subspecies of M. musculus. The variation in C-band size among these inbred strains can serve as a useful codominant cytological marker for estimating recombinational distances between the centromere and proximal genes in linkage crosses.
The mouse Y* chromosome involves a complex rearrangement, including interstitial positioning of the pseudoautosomal region
Authors: Eicher E.M. , Hale D.W. , Hunt P.A. , Lee B.K. , Tucker P.K. , King T.R. , Eppig J.T. , Washburn L.L.
Published: May 2008

Cytological analysis of the mouse Y* chromosome revealed a complex rearrangement involving acquisition of a functional centromere and centromeric heterochromatin and attachment of this chromosomal segment to the distal end of a normal Y chromosome. This rearrangement positioned the Y short-arm region at the distal end of the Y* chromosome and the pseudoautosomal region interstitially, just distal to the newly acquired centromere. In addition, the majority of the pseudoautosomal region was inverted. Recombination between the X and the Y* chromosomes generates two new sex chromosomes: (1) a large chromosome comprised of the X chromosome attached at its distal end to all of the Y* chromosome but missing the centromeric region (XY*) and (2) a small chromosome containing the centromeric portion of the Y* chromosome attached to G-band-negative material from the X chromosome (Y*X). Mice that inherit the XY* chromosome develop as sterile males, whereas mice that inherit the Y*X chromosome develop as fertile females. Recovery of equal numbers of recombinant and nonrecombinant offspring from XY* males supports the hypothesis that recombination between the mammalian X and Y chromosomes is necessary for primary spermatocytes to successfully complete spermatogenesis and form functional sperm.
Detection of structural chromosome aberrations in immunophenotyped mitoses
Authors: Schlegelberger B. , Weber-Matthiesen K. , Eumann S. , Rathjen M. , Grote W.
Published: May 2008

The recently developed MAC (morphology-antibody-chromosome) method allows simultaneous immunophenotype and karyotype analysis in the same cell. To date, application of this new method has been hampered by the poor quality of chromosome banding. In this paper, we describe a modified simultaneous immunofluorescence and Q-banding technique, as well as a new combination of immunohistochemical and fluorescent R-banding methods. By further modifying the MAC method, we were able not only to achieve unequivocal results with weakly expressed antigens but also to improve the quality of the banding techniques, so that even structural chromosome abnormalities were well defined.
Isolation and comparative mapping of a human chromosome 20-specific α-satellite DNA clone
Authors: Baldini A. , Archidiacono N. , Carbone R. , Bolino A. , Shridhar V. , Miller OJ. , Miller DA. , Ward DC. , Rocchi M.
Published: May 2008

We have isolated and characterized a human genomic DNA clone (PZ20, locus D20Z2) that identifies, under high-stringency hybridization conditions, an alphoid DNA subset specific for chromosome 20. The specificity was determined using fluorescence in situ hybridization. Sequence analysis confirmed our previously reported data on the great similarity between the chromosome 20 and chromosome 2 alphoid subsets. Comparative mapping of pZ20 on chimpanzee and gorilla chromosomes, also performed under high-stringency conditions, indicates that the alphoid subset has ancestral sequences on chimpanzee chromosome 11 and gorilla chromosome 19. However, no hybridization was observed to chromosomes 21 in the great apes, the homolog of human chromosome 20.
A physical and genetic linkage map of the distal long arm of human chromosome 5
Authors: Thangavelu M. , Neuman W.L. , Espinosa III R. , Nakamura Y. , Westbrook C.A. , Le Beau M.M.
Published: May 2008

By in situ hybridization of probes for three cloned genes and eight genetically-linked polymorphic DNA markers, we have prepared a physical map of the distal long arm of chromosome 5. These results, together with the localizations of 11 genes and the genetic linkage map reported previously by us and by other investigators, represent a map that spans 55 cM.
Localization of the rat insulin I gene (INS1) to chromosome 1q55 by fluorescence in situ hybridization
Authors: Mori M. , Ishizaki K. , Serikawa T. , Yamada J.
Published: May 2008

The rat insulin I gene (INS1) was assigned to chromosome 1q55 using fluorescent in situ hybridization. In addition, several RFLPs were detected among 11 inbred rat strains.
Defective repair of radiation-induced chromosomal damage in scid/scid mice
Authors: Disney J.E. , Barth A.L. , Shultz L.D.
Published: May 2008

The murine severe combined immunodeficiency (scid) mutation interferes with normal recombination of iramunoglobulin and T-cell receptor genes. This immunologic defect results in a lack of fully differentiated B and T cells in scid/scid mice. Animals homozygous for the scid mutation also display increased sensitivity to the damaging effects of ionizing radiation. We report here our observations of high frequencies of radiation-induced chromatid interchanges and intrachanges in bone marrow cells and fibroblasts from scid/scid mice. The presence of these aberrant chromosome structures suggests that a delay in strand rejoining underlies the increased sensitivity of scid/scid mice to ionizing radiation. The scid mutation may provide important clues for understanding the relationship between mitotic recombination and DNA repair in higher eukaryotic cells.
Assignment of two markers carried by human chromosome 1 to different cattle synteny groups: FH to U1 and PEPC to U17 (chromosome 8)
Authors: Arruga M.V. , Monteagudo L.V. , Tejedor M.T.
Published: May 2008

Two loci located on human chromosome 1 were mapped in cattle by means of interspecific (hamster × cattle) somatic cell hybridization. FH is assigned to the U1 synteny group together with PGD, ENO1, AT3, and REN, while PEPC is found to belong to the U17 group (chromosome 8), like FN1, CRYG, and VIL1.
Localization of the pig luteinizing hormone/choriogonadotropin receptor gene (LHCGR) by radioactive and nonradioactive in situ hybridization
Authors: Yerle M. , Galman O. , Lahbib-Mansais Y. , Gellin J.
Published: May 2008

The porcine gene for luteinizing hormone/choriogonadotropin receptor (LHCGR) was localized to chromosome 3q2.2→q2.3 using radioactive and nonradioactive in situ hybridization. A computer-assisted image-analysis system was developed which facilitated detection of the position of silver grains and fluorescent spots on the chromosomes after in situ hybridization. Compared with autoradiographic visualization, the nonisotopic procedure proved to be more rapid, precise, and highly specific; however, nonradiographic in situ hybridization was much less efficient than the autoradiographic technique for the detection of unique DNA sequences with small probes. From these results and published gene-mapping data, it was concluded that the synteny between LHCGR and MDH1 observed in man is conserved in the pig genome.
Equalization of Z and W axes in chicken and quail oocytes
Authors: Solari A.J.
Published: May 2008

The different morphological types of ZW pairs have been classified in three main types according to the relative extension of the free segment of the Z axis: 1 “long asynaptic segment;” 2, “medium asynaptic segment;” and 3, “equalized.” Pre- and post-pairing types have also been defined. Frequencies of each type were determined at day 20 and day 21 of incubation, and one and three days after hatching. The changing frequencies and the morphological transitions observed show a definite sequence of ZW types that can be used as a timetable for pachytene substaging. Measurements made on each ZW type show that the Z axis of the chicken shortens from 20.6 µm to 13.1 µm. This shortening occurs both in the free segment (at a higher rate) and in the paired segment (at a lower rate). The synaptonemal complex becomes elongated while adjustment occurs. The equalized Z axis makes many twists around the W axis. However, a segment 1 µm long from the synaptic terminus is free from twists and is assumed to be the homologously paired region. The ZW pair of the quail shows a similar behavior but equalization of the Z and W axes ends earlier and forms a straighter synaptonemal complex as compared with the chicken. In both species a recombination nodule is strictly localized near the synaptic terminus. In the ZW pair of the quail the average location of this nodule is 0.14 µm from the synaptic terminus. The meiotic behavior of ZW pairs in birds may be conserved.
Characterization of a human chromosome 8 cosmid library constructed from flow-sorted chromosomes
Authors: Wood S. , Schertzer M. , Drabkin H. , Patterson D. , Longmire J.L. , Deaven L.L.
Published: May 2008

A cosmid library for human chromosome 8 has been constructed from flow-sorted chromosomes in the vector sCos-1. This library is 85% human and has been arrayed into 210 microtiter plates representing four genome equivalents. Cosmids have been isolated with 10 of 11 probes representing nine different loci from chromosome 8.
Mechanisms of loss of heterozygosity in retinoblastoma
Authors: Zhu X. , Dunn J.M. , Goddard A.D. , Squire J.A. , Becker A. , Phillips R.A. , Gallie B.L.
Published: May 2008

Retinoblastoma (RB) tumors arise when both alleles of the RBI gene are inactivated by two mutational events (Ml and M2). Ml can be an initial germline or somatic mutation; M2 is frequently loss of heterozygosity (LOH), which makes the cell homozygous or hemizygous for the original mutation. LOH is the major mechanism by which many cancers are initiated. To further delineate the mechanism of LOH, we screened a total of 37 RB tumors for LOH by Southern blot analysis. The tumors were from 17 bilaterally and 17 unilaterally affected patients. Nineteen of 30 informative tumors (63 %) from 27 patients showed LOH. Proximal and distal flanking markers on chromosome 13 were informative in 13 tumors, allowing evaluation of the mechanisms by which LOH occurred. Mitotic recombination was implicated in 6 (46 %) of the 13 tumors.
The human catechol-O-methyltransferase (COMT) gene maps to band q11.2 of chromosome 22 and shows a frequent RFLP with BglI
Authors: Winqvist R. , Lundström K. , Salminen M. , Laatikainen M. , Ulmanen I.
Published: May 2008

We have been able to assign the human catechol-O-methyltransferase gene (COMT) to chromosome 22q11.2 by using Southern blot analysis of panels of somatic cell hybrids and chromosomal in situ hybridization. Furthermore, Southern blot analysis of DNA from blood and bone marrow samples of a patient with chronic myeloid leukemia (CML), having an extra Philadelphia chromosome (Ph1) in addition to the one produced by the reciprocal translocation between chromosomes 9 and 22, showed increased COMT and BCR gene dosage as compared to DNAs originating from CML patients with only one Ph1 chromosome or from chromosomally normal individuals. Control hybridizations of the same blot with TCRG- and TCRA-specific probes showed corresponding signal intensities in all samples. A relatively frequent two-allele COMT gene RFLP (PIC = 0.37) was recognized in DNAs digested with BglI. Our gene mapping result is in concordance with that previously reported by Brahe et al. (1986), who used an autoradiozymogram assay on different somatic cell hybrids to map this gene to chromosome 22.
Assignment of the human renal dipeptidase gene (DPEP1) to band q24 of chromosome 16
Authors: Nakagawa H. , Inazawa J. , Inoue K. , Misawa S. , Kashima K. , Adachi H. , Nakazato H. , Abe T.
Published: May 2008

Renal dipeptidase (DPEP1) or dehydropeptidase-I (E.C.3.4.13.11) is a kidney membrane enzyme which hydrolyzes a variety of dipeptides. DPEP1 is implicated in the renal metabolism of glutathione and its conjugates and is also responsible for hydrolysis of betalactam antibiotics. Using a human DPEP 1 cDNA probe, we mapped the human renal dipeptidase gene to human chromosome 16 at band q24 by in situ hybridization.
The human ribonuclease/angiogenin inhibitor is encoded by a gene mapped to chromosome 11p15.5, within 90 kb of the HRAS protooncogene
Authors: Schneider R. , Higgins M.J. , Kieninger D. , Schneider-Scherzer E. , Hirsch-Kauffmann M. , Schweiger M. , Eddy R.L. , Shows T.B. , Zabel B.U.
Published: May 2008

Ribonuclease/angiogenin inhibitor (RAI) is a tight-binding inhibitor of ribonucleolytic and angiogenic activities involved in tumor progression. It is translated from various mRNAs differing in their 5 regions and originating from a single gene locus. Recently, this gene (RNH) has been assigned to 11p15.5, the terminal part of the short arm of chromosome 11. The regional chromosomal localization was confirmed by somatic cell and in situ hybridization and further refined by long-range restriction mapping. The data place RNH within 90 kb of the Harvey-ras protooncogene (HRAS), so far the most telomeric gene on 11p, in a region involved in growth regulation and tumor development.
Unpaired chromosomes at meiosis: cause or effect of gametogenic insufficiency?
Authors: Mittwoch U. , Mahadevaiah S.K.
Published: May 2008

Pairing failure at meiosis has been postulated as a cause of gametogenic arrest in both heterozygous translocation carriers and males whose spermatocytes exhibit univalent X and Y chromosomes. The present investigation is a survey of pachytene translocation configurations, at the electron microscopic level, in six stocks of mice, comprising a total of 464 spermatocytes and 343 oocytes. Univalence of the X and Y chromosomes was studied in the same stocks, as well as in three additional homozygous translocation stocks. Fully paired as well as asynaptic configurations were found in all translocation stocks, and the proportions of each configuration differed considerably between spermatocytes and oocytes of mice carrying the same translocation. In both spermatocytes and oocytes, other pairing anomalies were more frequent in cells with asynapsed than with fully synapsed configurations, and spermatocytes with univalent sex chromosomes had a higher proportion of autosomal anomalies than did spermatocytes with XY bivalents. It is concluded that pairing failure at meiosis is primarily a symptom, rather than a cause, of gametogenic arrest, and that chromosome rearrangements, even if they appear to be balanced, may affect the rate of atresia by interfering with the normal rate of meiotic progression. Once pairing failure is established, it could secondarily increase the probability of gametogenic failure.
Transmission of gametes with normal or translocation chromosomes in male and female single-sex mouse chimeras
Authors: de Boer P. , van der Hoeven F.A. , Schöller J.M.G.M.
Published: May 2008

Three male and four female mouse single-sex chimeras derived from fusions of Rb(11.13)4Bnr T(1;13)70H homozygous embryos with +/+ embryos were caged with T(1;13)70H homozygotes of the opposite sex and followed through their reproductive lifespans. Six animals (three males and three females) were germline chimeras. The fz gene was used as a marker for the T70H reciprocal translocation. The ratio fzfz to fz/+ offspring did not change with increasing age in males, but decreased in two of the three female chimeras. Within males, there was generally good agreement between the proportions of translocation and nontranslocation germ cells from spermatogonial mitosis through the first and second meiotic division. In one male, this ratio was also reflected in the offspring. In the other two males, there was significant selection during haplophase, from which both types of spermatozoa could benefit.
Intra- and interspecific genome-size variation in the Salmonidae
Authors: Lockwood S.F. , Derr J.N.
Published: May 2008

The nuclear DNA contents of 22 salmonid taxa, estimated primarily by flow-cytometric analysis relative to a chicken internal standard, were evaluated to compare intra- and interspecific variation in DNA content within this fish family. The average variability within taxa exceeded that among taxa. Intraspecific genome-size variation was substantial and, in some cases, exceeded the mean genome size for the species. The flow-cytometric method used here allows for rapid and reliable comparison of nuclear DNA contents within and among individuals from natural animal populations.
A simple method for simultaneous R- or G-banding and fluorescence in situ hybridization of small single-copy genes
Authors: Lemieux N. , Dutrillaux B. , Viegas-Péquignot E.
Published: May 2008

A significant improvement in fluorescence in situ hybridization, enabling the detection of single-copy genes as small as 500 bp directly on banded chromosomes, is presented. The induction of chromosome banding, which does not require additional handling or any system of amplification, is obtained simply by using an alkaline (pH 11) p-phenylenediamine anti-fade solution. As the banding produced is related to the timing of 5-bromodeoxyuridine incorporation, either R- or G-banding, constitutive heterochromatin staining, or chromosome asymmetry can be observed simultaneously with the fluorescent hybridized spots. Results of hybridization of small cDNA probes for the human genes for motilin, thymidylate synthetase, and lymphocyte activation-3 are provided as examples of the high-resolution mapping obtainable with this technique.
Fast one-step procedure for the detection of nucleic acids in situ by primer-induced sequence-specific labeling with fluorescein-12-dUTP
Authors: Koch J. , Mogensen J. , Pedersen S. , Fischer H. , Hindkjær J. , Kølvraa S. , Bolund L.
Published: May 2008

We provide fast, simple, one-step procedures for sequence-specific detection of nucleic acids in situ. Tandem repeat sequences in DNA are stained within 30 min, and mRNA is stained within 2 h. The procedures are based on the incorporation of the newly available fluorescein-labeled dUTP into DNA synthesized in situ by primed in situ labeling, with denatured fragments of cloned DNA or oligonucleotides as primers. The extreme speed and simplicity of the reaction make it attractive for automatization in routine laboratory procedures and opens up new diagnostic possibilities.
A microchromosome derived from chromosome 11 in a patient with the CREST syndrome of scleroderma
Authors: Haaf T. , Summer A.T. , Köhler J. , Willard H.F. , Schmid M.
Published: May 2008

A patient with the CREST syndrome of scleroderma was found to carry a mosaicism for a supernumerary microchromosome. The microchromosome was ∼1 µm in size and present in over half of the lymphocyte metaphases examined. It bound centromeric proteins specifically recognized by CREST autoimmune sera (including the patient’s serum). In situ hybridization with a panel of chromosome-specific α-satellite probes showed that the microchromosome was derived from chromosome 11 most or all of its chromatin consisting of the chromosome 11 subset of α-satellite DNA. It had no detectable telomeric sequences. Microchromosomes observed by electron microscopy had no visible free ends. The chromatin looked exactly the same as it did in normal chromosomes. Although we have no direct evidence for a circular structure, we conclude that the microchromosome originated by an interstitial deletion including the α-satellite DNA sequences and subsequent ring formation. The newly formed chromosomal element proved to be relatively stable somatically and was transmitted through meiosis. Since it possesses at least some structural and functional features of a centromeric region, the microchromosome can be thought of as an isolated centromere.
Localization of the catalytic subunit Cγ of the cAMP-dependent protein kinase gene (PRKACG) to human chromosome region 9q13
Authors: Foss K.B. , Simard J. , Bérubé D. , Beebe S.J. , Sandberg M. , Grzeschik K.-H. , Gagné R. , Hansson V. , Jahnsen T.
Published: May 2008

A cDNA for a new catalytic subunit (Cγ) of the cAMP-dependent protein kinase (PKA) was recently isolated from a human testis cDNA library. This subunit was shown to be expressed only in testis, and has so far not been demonstrated in other species. In the present study, we have determined the chromosomal localization of this gene employing a cDNA for Cγ as a probe. Southern blot analysis of genomic DNA from human × mouse somatic cell hybrids allowed us to assign this gene (PRKACG) to human chromosome 9. In situ hybridization to metaphase chromosomes confirmed the somatic cell hybrid data and regionally mapped the Cγ gene of PKA to human chromosome 9q13.
BEK, a receptor for multiple members of the fibroblast growth factor (FGF) family, maps to human chromosome 10q25.3→q26
Authors: Dionne C.A. , Modi W.S. , Crumley G. , O’Brien S.J. , Schlessinger J. , Jaye M.
Published: May 2008

The gene for the fibroblast growth factor receptor BEK was assigned to human chromosome 10 by applying polymerase chain reaction techniques to DNAs from a panel of human × rodent somatic cell hybrids. The gene was further localized to 10q25.3→q26 by in situ hybridization.
Intragenomic movement and concerted evolution of satellite DNA in Peromyscus: evidence from in situ hybridization
Authors: Hamilton M.J. , Hong G. , Wichman H.A.
Published: May 2008

Four DNA probes isolated from Peromyscus leucopus were used to examine intra- and interspecific variation in the chromosomal location of satellite DNA in the genus Peromyscus. All four probes hybridized to the centromeric regions of all chromosomes in all species of Peromyscus examined but did not hybridize to the majority of heterochromatic regions in closely related non-Peromyscus species. One probe contains a nonsatellite repetitive sequence. The implications of these data to the evolution of genome organization are discussed.
Genetic variation in the African rodent subfamily Otomyinae (Muridae)
Authors: Contrafatto G. , Campbell G.K. , Taylor P.J. , Goossens V. , Willan K. , Meester J.A.
Published: May 2008

Results of chromosome G- and C-banding studies on 12 specimens of the ice rat, Otomys sloggetti robertsi, from three localities and allozyme analyses of seven individuals from two localities are reported. The subspecies karyotype contains 42, mostly acrocentric, chromosomes. No chromosomal variation was detected among animals from these localities. Allozyme analysis tentatively suggested a limited gene flow between the two populations examined.
Comparative cytogenetic studies in tree shrews (Tupaia)
Authors: Toder R. , von Holst D. , Schempp W.
Published: May 2008

Through use of BrdU replication, RBA-banded karyotypes of Tupaia belangeri, T. chinensis, and T. glis were obtained. A chromosome number of 2n = 62 for T. belangeri is described here for the first time and is confirmed for T. chinensis. All chromosomes between these two phenotypically different species appear to have identical RBA banding patterns; in addition, there is no difference between T. belangeri and T. chinensis in the number and position of nucleolus organizer regions (NORs). The reduced chromosome number of 2n = 60 in T. glis can be explained by a Robertsonian translocation between two acrocentric chromosome pairs, Nos. 10 and 13, of T. belangeri and/or T. chinensis, resulting in the metacentric chromosome pair 1 of T. glis. Furthermore, two chromosome pairs each of T. glis and T belangeri and/or T. chinensis are not homoeologous, as judged by their RBA patterns. Differences were also found in the number and position of NORs; whereas T. glis displays eight positively stained NORs after AgNO3 staining, there are only four silver-stained NORs in both T. belangeri and T. chinensis. The possibility of geographical isolation as an explanation for the lack of chromosomal differentiation between T. belangeri and T. chinensis is discussed.
Severely reduced recombination in females of the South American marsupial Monodelphis domestica
Authors: van Oorschot R.A.H. , Porter P.A. , Kammerer C.M. , VandeBerg J.L.
Published: May 2008

The gray short-tailed opossum, Monodelphis domestica, is a model species for studying the underlying mechanisms that govern recombination. We have identified a new marker, PI (protease inhibitor), in M. domestica and demonstrate its linkage to AK1 (adenylate kinase 1). The rate of recombination in females of this species is approximately one fifth the rate in males, as might be predicted from the difference in chiasma frequency between the two sexes.
Male common shrews (Sorex araneus) with long meiotic chain configurations can be fertile: implications for chromosomal models of speciation
Authors: Mercer S.J. , Wallace B.M.N. , Searle J.B.
Published: May 2008

Two chromosomal races of common shrews (Sorex araneus) were crossed in captivity to generate chain VH-forming complex Robertsonian heterozygotes. Meiosis and gametogenesis were studied in three male hybrids. Regular chain VII configurations were observed at both pachytene and diakinesis/metaphase I, although in many pachytene spreads the chain configuration was incomplete (the basis of this peculiarity is unknown). From metaphase II counts, the frequency of anaphase I nondisjunction in the complex heterozygotes was estimated to be 13 %. Germ-cell death in the chain VII-forming complex heterozygotes was 22 % greater than it was in controls, but this difference is unlikely to have greatly influenced the capacity of the heterozygotes to sire offspring. Thus, the fecundity of these complex heterozygous common shrews would probably have been only slightly reduced relative to homozygous or simple heterozygous shrews. These results call into question the generality of speciation models based on the presumed sterility of complex heterozygotes.
Analysis of sex-chromosome aneuploidy in interspecific backcross progeny between the laboratory mouse strain C57BL/6 and Mus spretus
Authors: Matsuda Y. , Chapman V.M.
Published: May 2008

Sex-chromosomal aneuploidy was identified in four female progeny of 200 interspecific backcrosses between laboratory mice (C57BL/6Ros) and Mus spretus. The progeny included two 39, XO monosomy mice resulting from a backcross with M. spretus, as well as a 41, XXX trisomic mouse and a 40, XX/41, XXX mosaic mouse resulting from two separate backcrosses with C57BL/6 mice. The parental origin and meiotic stage of the aneuploidies was determined for each of the mice using a series of markers that identified allelic differences in the parental X-chromosome genes present in the hybrid female. Two of the probes identified differences in repeated elements between the M. spretus and laboratory mouse X chromosomes, whereas the remaining sites involved restriction fragment length differences of single-copy genes detectable by Southern analysis. These markers indicated that the aneuploidies were most likely of maternal origin and that the trisomy resulted from a nondisjunction at the second meiotic division. In contrast, the mosaic female could have originated either from a trisomic embryo that had lost a single X in a portion of its cells or from a mitotic nondisjunction during early embryogenesis that resulted in XXX and XO daughter cells, with subsequent loss of the XO cells.
Isolation of monochromosomal hybrids following fusion of human diploid fibroblast-derived microcells with mouse A9 cells
Authors: Ning Y. , Lovell M. , Taylor L. , Pereira-Smith O.M.
Published: May 2008

Rodent × human hybrids containing single human chromosomes are valuable tools in the study of human genetics. Using a retrovirus carrying the neomycin gene, we generated a neomycin-resistant (neor) pool of human diploid fibroblasts. Following fusion of microcells prepared from this pool to mouse A9 cells, we obtained four neor hybrids containing a single human chromosome 2, 3, 5, or 15.
Distribution of satellite DNA fractions within major heterochromatic regions of human chromosomes as revealed by PleI and TfiI digestion
Authors: Tagarro I. , Fernández-Peralta A.M. , González-Aguilera J.J.
Published: May 2008

Banding patterns induced by selective DNA extraction with the restriction endonucleases PleI and TfiI reveal the distribution of human satellite DNAs within the major heterochromatic blocks on human metaphase chromosomes. PleI and TfiI are able to discriminate HinfI target sites, depending on the nature of the central base. PleI digestion specifically reveals regions, within major C-bands, that include the major sites of satellite II DNA and permits more precise localization of satellite II domains than does radioactive in situ hybridization. The close correspondence between the cytogenetic results presented here and previously reported molecular data seems to support the idea that the frequency of enzyme target sequences is the main factor in determining the action produced by restriction endonucleases on fixed human chromosomes and that chromatin conformation is not an important factor in limiting enzyme accessibility.
Expression of decorin in human tissues and cell lines and defined chromosomal assignment of the gene locus (DCN)
Authors: Pulkkinen L. , Alitalo T. , Krusius T. , Peltonen L.
Published: May 2008

Earlier studies had shown that the expression of the gene coding for one eminent connective tissue proteoglycan, decorin (DCN), is deficient in the fibroblasts of 3 out of 15 Marfan patients (Pulkkinen et al., 1990). To obtain more information on the expression of this gene, various human tissues and cell lines were studied. High mRNA levels of decorin were detected in aorta, lung, skin, kidney, smooth muscle, and placenta, whereas significantly lower mRNA levels were found in the rest of the tissues analyzed. Two sizes of transcripts were observed in all tissues. The two transcripts of decorin most probably do not represent two different genes, since in situ hybridization gave only one strong signal, placing the gene in 12q21→q22. No tissue-specific differences in the two mRNA species of decorin were detected. This is in contrast to the gene of versican, another connective tissue proteoglycan gene, that was analyzed as a control; high expression of a longer transcript of the versican gene was found in brain and smooth muscle, whereas the shorter transcript was predominant in all other tissues studied. DCN was actively transcribed in cultured mesenchymal cells, whereas in cells of endothelial or epithelial origin, the transcription level was undetectable. These tissue- and cell type-specific variations in the expression of DCN may help to explain the complex phenotypic variation typical of individuals with Marfan syndrome.
Localization of the 5’ end of the MCF2 oncogene to human chromosome 15q15→q23
Authors: Galland F. , Stefanova M. , Lafage M. , Birnbaum D.
Published: May 2008

Oncogenic activation of the MCF.2 cell line-derived transforming sequence gene (MCF2) occurs through substitution of part of its 5’ coding region by unrelated nonsyntenic sequences. Analysis of the MCF2 oncogene locus revealed complex recombination events involving four discontinuous human DNA segments. The upstream replacing sequence, named URS, represents the farthest 5’ portion of the locus. The URS sequence maps to the D15S93 locus on human chromosome 15q15→q23.
The human protein-tyrosine phosphatase PTPα/LRP gene (PTPA) is assigned to chromosome 20p13
Authors: Jirik F.R. , Anderson L.L. , Duncan A.M.V.
Published: May 2008

In situ hybridization was employed to localize a cDNA probe from the human protein-tyrosine phosphatase PTPα/LRP to human metaphase chromosomes. The PTPA gene has been localized to chromosome 20p13.
A recurrent marker chromosome involving chromosome 1 in two mammary tumors of the dog
Authors: Bartnitzke S. , Motzko H. , Caselitz J. , Kornberg M. , Bullerdiek J. , Schloot W.
Published: May 2008

An apparently identical marker chromosome resulting from a chromosome 1 translocation was found in the mammary carcinomas of two bitches. Although these karyotypic aberrations were the sole clonal aberrations detected, it was not possible to unambiguously identify the material translocated to the chromosome 1 in either animal. Our observations, however, represent the first report of a recurring marker chromosome in mammary tumors of the dog and suggest that these tumors may become an interesting model for human breast cancer.
Evidence for genetic etiology of heteroploidy in embryos of the Japanese quail (Coturnix coturnix japonica)
Authors: de la Seña C.A. , Fechheimer N.S. , Nestor K.E.
Published: May 2008

The Japanese quail was used as an experimental system to detect the effects of genes that affect chromosome behavior and distribution. From a random-bred population, three inbred generations were produced by full-sib matings in 36 families. The expectation from such a breeding scheme was that embryos bearing aberrations induced by recessive mutant genes would cluster within families and recur in particular lineages. Chromosomal aberrations caused by errors during fertilization, cleavage mitosis, and gametogenesis were scored in 2,037 16- to 18-h embryos from 107 families. Comparisons of the observed frequencies among families and lineages and pedigree analysis indicated that four types of chromosome aberrations had a genetic basis: (1) triploidy and triploid chimerism; (2) haploidy and haploid chimerism; (3) diploid/tetraploid mosaicism; and (4) a new aberration, referred to as “atypical mitotic meta-phase.” Analysis of the sex-chromosome complements of the embryos indicated that triploidy resulted predominantly from diploid ova, haploid cell lines originated from supernumerary sperm nuclei, and tetraploid cell lines resulted from endoreduplication or failure of cytokinesis. Clustering of triploidy in particular lineages was due to dispermy or recurrent suppression of one or both meiotic divisions during oogenesis.
Detection of retinoblastoma gene copy number in metaphase chromosomes and interphase nuclei by fluorescence in situ hybridization
Authors: Kallioniemi A. , Kallioniemi O.-P. , Waldman F.M. , Chen L.-C. , Yu L.-C. , Fung Y.K.T. , Smith H.S. , Pinkel D. , Gray JW.
Published: May 2008

Fluorescence in situ hybridization (FISH) was applied to detect the copy number of the retinoblastoma (RB1) tumor suppressor gene in metaphase chromosomes and interphase nuclei. We used 14 λ phage clones spanning the whole RB1 gene region as a probe and obtained a specific hybridization signal in normal metaphase chromosomes at 13q14. Normal interphase nuclei showed two RB1 signals in about 90% of cases, whereas two cell lines with cytogenetically defined deletions involving the RB1 gene showed only one hybridization signal in about 80% of the nuclei. Analogous changes were detected in metaphase chromosomes. Multicolor FISH with subsets of the phage clones allowed visualization of subregions within the 200-kb gene in interphase nuclei. Analysis of clinical breast cancer samples showed that most of the cells contained two copies of the RB1 gene, even when restriction fragment length polymorphism analysis showed loss of heterozygosity (LOH) at the RB1 locus. This indicates that LOH at the RB1 locus in breast cancer cells probably involves mechanisms other than physical deletion.
Regional mapping of a liver α-subunit gene of phosphorylase kinase (PHKA) to the distal region of human chromosome Xp
Authors: Wauters J.G. , Bossuyt P.J. , Davidson J. , Hendrickx J. , Kilimann M.W. , Willems P.J.
Published: May 2008

X-linked liver glycogenosis (XLG) is a glycogen storage disorder resulting from deficient activity of phosphorylase kinase (PHK). PHK consists of four different subunits: α, β, γ, and δ. Several genes encoding PHK subunits have been cloned and localized, but only the muscle α-subunit (PHKA) gene has been assigned to the X chromosome, in the region Xq12→q13. However, we have previously excluded the muscle PHKA gene as a candidate gene for the XLG mutation, as linkage analysis indicated that the mutation responsible for XLG is located in Xp22 and not in Xq12→q13. We report here the chromosomal localization by in situ hybridization of a liver PHKA gene to the distal region of chromosome Xp. Strong hybridization signals were observed on the distal part of the short arm of a chromosome identified as the X chromosome by cohybridization with an X chromosome-specific centromeric probe. The localization of this gene in the same chromosomal region as the disease gene responsible for XLG suggests that the liver PHKA gene is a highly likely candidate gene for the XLG mutation.
Assignment of the human connexin 32 gene (GJB1) to band Xq13
Authors: Raimondi E. , Gaudi S. , Moralli D. , De Carli L. , Malcovati M. , Simonic T. , Tenchini M.L.
Published: May 2008

The chromosomal localization of the human gene coding for connexin 32 (GJB1) was determined by in situ suppression hybridization (ISSH). The results allowed assignment of the gene to band Xq13, thus refining previous localization data obtained by means of somatic cell hybrid analysis.