bluuebunny/crossref_metadata_2025 huggingface dataset:
The thyroglobulin gene is syntenic with the MYC and MOS protooncogenes and carbonic anhydrase II and maps to chromosome 14 in cattle
Authors: Threadgill D.W. , Fries R. , Faber L.K. , Vassart G. , Gunawardana A. , Stranzinger G. , Womack J.E.
Published: May 2008

Using a panel of bovine x Chinese hamster hybrid somatic cells, sequences homologous to genes spanning human chromosome arm 8q have been syntenically assigned in cattle. Thyroglobulin (TG), carbonic anhydrase II (CA2), and the protooncogenes MYC and MOS were assigned to a newly identified bovine syntenic group, U23. Additionally, in situ hybridization of the thyroglobulin probe to bovine metaphase chromosomes revealed this syntenic group to be on bovine chromosome 14 and the bovine thyroglobulin gene to reside at 14q12→q15.
Chromosome 1 localization of the gene for CD34, a surface antigen of human stem cells
Authors: Tenen D.G. , Satterthwaite A.B. , Borson R. , Simmons D. , Eddy R.L. , Shows T.B.
Published: May 2008

CD34 is a surface antigen expressed on normal human hematopoietic stem cells, as well as on the blast cells of many patients with both lymphocytic and myelocytic leukemias. By Southern blot analysis of DNA from a panel of human × mouse somatic cell hybrids using a CD34 cDNA probe, we demonstrate that the gene for CD34 is located on human chromosome 1 in the 1q12→qter region.
A second nonrandom translocation, der(16)t(1;16)(q21;q13), in Ewing sarcoma and peripheral neuroectodermal tumor
Authors: Douglass E.C. , Rowe S.T. , Valentine M. , Parham D. , Meyer W.H. , Thompson E.I.
Published: May 2008

The majority of Ewing sarcomas and peripheral neuroectodermal tumors (PNET) that have been karyotyped contain a specific translocation, t(11;22)(q23;q11). We report here a second nonrandom translocation, der( 16)t(1; 16)(q21;q13), in 2 of 20 cases of Ewing sarcoma (seven previously unreported) and 2 of 7 cases of PNET (all previously unreported). All cases with this translocation also contained the t(l 1;22). Comparison of C-banding patterns in tumor and peripheral lymphocyte karyotypes in one case indicated that the likely breakpoints were lq21 and 16q13. The presence of this translocation in cell lines will enable further investigation of the molecular events important in the pathogenesis of Ewing sarcoma and PNET.
Synaptonemal complex analysis of spermatocytes of Talpa occidentalis(Insectivora, Mammalia): autosomal synapsis and substaging of zygonema and pachynema
Authors: Jiménez R. , Burgos M. , Sánchez A. , de la Guardia Díaz
Published: May 2008

Spermatocytes from the mole, Talpa occidentalis, a species that includes both XX males and intersexes, were surface-spread and silver-stained to substage meiotic prophase from early zygonema through pachynema. In zygonema, only the Z2 and Z3 substages were found. This stage differed in comparison with such species as the Chinese hamster, laboratory mouse, and deer mouse, which belong to orders other than Insectivora. Pachynema, in which five substages were established (P1-P5), seems to be a more homogeneous stage, and remarkable differences with respect to the above-mentioned species were not found. Synaptic adjustment was demonstrated in X-Y pairing. Nonhomologous pairing was evident at the Y-centromeric region and considered likely in the proximal arm of this chromosome. In addition to sequencing the events taking place during zygonema and pachynema in males from a wild population in which some members show sex reversal, our finding represents the first attempt to substage zygonema and pachynema in an Insectivore species, thus contributing to current knowledge of the nature and degree of variability in the mammalian synaptic process.
The frequency of aneuploidy among individual chromosomes in 6,821 human sperm chromosome complements
Authors: Martin R.H. , Rademaker A.
Published: May 2008

The human sperm/hamster egg fusion technique has been used to analyse 6,821 human sperm chromosome complements from 98 men to determine if all chromosomes are equally likely to be involved in aneuploid events or if some chromosomes are particularly susceptible to nondisjunction. The frequency of hypohaploidy and hyperhaploidy was compared among different chromosome groups and individual chromosomes. In general, hypohaploid sperm complements were more frequent than hyperhaploid complements. The distribution of chromosome loss in the hypohaploid complements indicated that significantly fewer of the large chromosomes and significantly more of the small chromosomes were lost, suggesting that technical loss predominantly affects small chromosomes. Among the autosomes, the observed frequency of hyperhaploid sperm equalled the expected frequency (assuming an equal frequency of nondisjunction for all chromosomes) for all chromosome groups. Among individual autosomes, only chromosome 9 showed an increased frequency of hyperhaploidy. The sex chromosomes also showed a significant increase in the frequency of hyperhaploidy. These results are consistent with studies of spontaneous abortions and liveborns demonstrating that aneuploidy for the sex chromosomes is caused by paternal meiotic error more commonly than aneuploidy for the autosomes.
Mapping of the gene for DNA polymerase β to mouse Chromosome 8
Authors: McBride O.W. , Kozak C.A. , Wilson S.H.
Published: May 2008

We conducted Southern blot analysis of DNAs from mouse × hamster somatic cell hybrids and progeny of an interspecies backcross to localize the mouse gene for DNA polymerase β (Polb) to the centromeric end of Chromosome 8 These results provide additional support for the regional localization of polymerase β. on the short arm of human chromosome 8 or the veryproximal end of the long arm.
Localization of the repetitive telomeric sequence (TTAGGG)n in two muntjac species and implications for their karyotypic evolution
Authors: Scherthan H.
Published: May 2008

It has been suggested that the chromosome set of the Indian muntjac, Muntiacus muntjak vaginalis (female, 2n = 6; male, 2n = 7), evolved from small acrocentric chromosomes, such as those found in the complement of the Chinese muntjac, M. reevesi (2n = 46), by a series of tandem fusions and other rearrangements. The location of the highly conserved human telomeric sequence (TTAGGG)n in the metaphase chromosomes of M. m. vaginalis and its close relative, M. reevesi, was investigated by non-radioactive in situ hybridization. The (TTAGGG)n repeat was found adjacent to the centromeres in the short arm and at the telomeres in the long arm of M. reevesi acrocentric metaphase chromosomes. Tandem fusions present in the karyotype of M.m. vaginalis chromosomes were not reflected by interstitial signals of the telomere repeat, as these chromosomes displayed hybridization signals only at the ends of the chromatids. Mechanisms that might have played a role in the evolution of the reduced karyotype of the Indian muntjac are discussed.
Trisomy 7, trisomy 10, and loss of the Y chromosome in short-term cultures of normal kidney tissue
Authors: Elfving P. , Cigudosa J.C. , Lundgren R. , Limon J. , Mandahl N. , Kristoffersson U. , Heim S. , Mitelman F.
Published: May 2008

Numerical chromosome aberrations are common in several types of malignant tumors. Recently, trisomy 7 and loss of the Y chromosome were described in cultures from nonneoplastic tissue, making the significance of these aberrations as cancer-associated changes doubtful. We herein report the mosaic occurrence of trisomy 7 in four consecutive short-term cultures initiated from normal kidney tissue. Smaller clones with trisomy 10 were present in three cases, and the only culture established from a male also showed mosaic loss of the Y chromosome.
The receptors for prolactin and growth hormone are localized in the same region of human chromosome 5
Authors: Arden K.C. , Boutin J.-M. , Djiane J. , Kelly P.A. , Cavenee W.K.
Published: May 2008

Prolactin receptor (PRLR) and growth hormone receptor (GHR) are encoded by members of a gene family containing regions of identical sequences. To determine their chromosomal locations, cDNA probes for these genes were used. Analysis of hybridization to several somatic cell hybrids, together with hybridization in situ to metaphase chromosomes, resulted in the assignment of the loci for both receptors to human chromosome 5 in the region p13→p14. Thus, these proteins may be encoded by a cluster of related genes that evolved from a common ancestral gene, in a manner consonant with that of their ligands.
Chromosome localization of two human serine protease genes to region 14q11.2→q12 by in situ hybridization
Authors: Lin C.C. , Meier M. , Sorensen O. , Sasi R. , Tainaka T. , Bleackley R.C.
Published: May 2008

Two human serine protease genes have been cloned. One corresponds to CTLAl, the human equivalent of the mouse cytotoxic cell protease gene Ctla-1, and the other is novel. Both genes were localized to 14q 11.2→q 12 by in situ hybridization. This result confirms the assignment of human CTLAl to 14q11.2→q12 and provides new mapping data for another human serine protease gene located in the same chromosome region.
Localisation of human PGP and HAGH genes to 16p13.3
Authors: Mulley J.C. , Barton N. , Callen D.F.
Published: May 2008

Gene loci for phosphoglycolate phosphatase and hydroxyacyl glutathione hydrolase were localized within human chromosome band 16pl3.3. This result was determined by the electrophoretic detection of enzymes from a human × mouse somatic cell panel, the members of which carried portions of human chromosome 16 with precisely defined breakpoints.
Correlation between meiotic behavior and breakpoints with respect to G-bands in two X-4 mouse translocations: T(X;4)7R1 and T(X;4)8R1
Authors: Ashley T. , Cacheiro N.L.A.
Published: May 2008

The meiotic synaptic behavior of male mice heterozygous for one of two X-4 translocations was examined to test a recently advanced hypothesis (Ashley, 1988) suggesting that it is possible to predict the synaptic behavior (nonhomologous vs. homologous) and recombinational parameters (suppression vs. nonsuppression of crossing-over) of a chromosome aberration from mitotic G-band breakpoint data. The hypothesis was based on prior observations of synaptic behavior in a series of X-autosome translocations in mice. The breakpoints of the transloca tion T(X;4)7R1 are both in G-light bands. As predicted by the hypothesis, synapsis was restricted to homology. In contrast, one breakpoint of the translocation T(X;4)8R1 lies in a “stippled” band of the standard diagrams of Nesbitt and Francke (1981). As predicted (Ashley, 1988), “stippled” bands are shown here to synapse nonhomologously, i.e., they behave as “G-dark.” The linkage data, as they relate to the synaptic data and the predictions of the hypothesis, are also discussed.
Sex-chromosome constitution of postimplantation tetraploid mouse embryos
Authors: O’Neill G.T. , Speirs S. , Kaufman M.H.
Published: May 2008

Tetraploid mouse embryos were produced at the two-cell stage by blastomere fusion induced by inactivated Sendai virus. The embryos were from chromosomally normal female mice that had been fertilised by homozygous Rb( 1.3)1 Bnr males carrying a pair of large metacentric marker chromosomes in their karyotype. These “reconstructed” one-cell tetraploid embryos were then transferred to the oviducts of pseudopregnant recipients, which were subsequently autopsied early on the 10th day of gestation. Two-cell stage embryos that did not undergo blastomere fusion after 4–5 h were transferred to a second group of recipients, which were also autopsied early on the 10th day of gestation. From a total of 153 tetraploid embryos transferred to females that subsequently became pregnant, 135 implanted. Sixty-eight implantation sites were found to contain resorptions, whereas 67 contained mostly headfold presomite-stage embryos. Four embryos possessed four to six pairs of somites. All 57 em bryos that could be analysed cytogenetically were found to be tetraploid. G-banding analysis revealed that 30 of these embryos had an XXYY and 27 an XXXX sex-chromosome constitution. The presence of two marker chromosomes in all mitotic preparations from each of these tetraploid embryos confirmed that they had all been produced by duplication of their original XY or XX diploid chromosome constitution, respectively. The XXYY:XXXX sex ratio observed was not significantly different from unity. In the control series of transfers, all of the embryos recovered were at the forelimb bud stage and had a diploid chromosome constitution. The results reported here differ from human clinical findings, in which the XXYY:XXXX sex ratio of 120 human tetraploid spontaneous abortions recovered over the last 20 years is 45:75. Possible explanations for these differences are briefly discussed.
Rapid identification of sex in birds by flow cytometry
Authors: Nakamura D. , Tiersch T.R. , Douglass M. , Chandler R.W.
Published: May 2008

A rapid method to identify sex in birds is described. The method requires microliter volumes of blood, and, under appropriate conditions, results can be available within an hour of sample collection. Samples can be stored at 4 C or–20 C with out sacrificing the ability to discriminate sex differences in DNA content. The assay will find utility in laboratory, field, and applied studies, in other classes of vertebrates, and in studies on the dynamics of genome size within and among populations.
In situ random primer extension of metaphase chromosomes
Authors: García de la Vega C. , Martínez Zapater J.M. , López-Fernández C. , Goyanes V. , Mezzanotte R. , Gosálvez J.
Published: May 2008

We have developed a technique of random primer extension of fixed chromosomes that is applicable to both mouse and man. Human chromosomes are not homogeneously labeled with this technique; those regions corresponding to R-bands appear to be more sensitive than those identified as G-bands, whereas centromeric regions are not labeled. These results not only cor roborate specific structural differences between distinct regions of mammalian genomes but also open up the possibility of assays with specific primers to test whether primer extension is useful for the identification of genes and families of sequences on chromosomes.
Localization and polymorphism of a chromosome 12-specific α satellite DNA sequence
Authors: Looijenga L.H.J. , Smit V.T.H.B.M. , Wessels J.W. , Mollevanger P. , Oosterhuis J.W. , Cornelisse C.J. , Devilee P.
Published: May 2008

The isolation and localization of a chromosome 12-specific α satellite DNA sequence, pα12H8, is described. This clone contains a complete copy of the 1.4-kb Hindlll higher-order repeat present within the α satellite array on chromosome 12. The specificity of pα12H8 was demonstrated by in situ hybridization and Southern blot analysis of a somatic cell hybrid mapping panel, both performed under high-stringency conditions. Polymorphic restriction patterns within the α satellite array, revealed by the use of the restriction enzymes Bglll and EcoRV, were demonstrated to display Mendelian inheritance. These properties make pα12H8 a valuable genetic marker for the centromeric region of chromosome 12.
In situ DNA sequence mapping with surface-spread mouse pachytene chromosomes
Authors: Moens P.B. , Pearlman R.E.
Published: May 2008

Surface-spread pachytene chromosomes are several times the length of metaphase chromosomes and the decondensed chromatin loops are attached to a well-defined axis (Weith and Traut, 1980). This arrangement permits detailed DNA sequence localization by in situ hybridization. We show that two probes to low-frequency repeated sequences (20 to 50 copies) which locate the centromere proximal in the mouse X metaphase chromosome between bands Al and A3 (Disteche et al., 1985) and which map 5.5 cM apart (Disteche et al., 1989), hybridize to two distinct chromatin regions 3 to 5 µm apart on a 25 µm long pachytene X chromosome core.
Analysis of the structure and variability of nucleolar organizer regions of Salmo trutta by C-, Ag-, and restriction endonuclease banding
Authors: Sánchez L. , Martínez P. , Viñas A. , Bouza C.
Published: May 2008

Nucleolar organizer regions (NORs) of brown trout were investigated using C-, Ag-, and restriction endonuclease banding. The presence of constitutive heterochromatin was confirmed by C-banding. Giemsa-staining, C-banding, and Ag-banding revealed great variability in the size of the short arm of the NOR-bearing chromosome. This size variation was due in some cases to NOR duplication. Restriction endonuclease digestion induced a specific banding pattern for Alul, Ddel, Haelll, Mbol, and Hinñ, indicating some features about the sequence composition of the NOR-associated heterochromatin.
Visualization of DNA in pachytene by monoclonal antibodies against BrdU reveals synaptonemal complex-like structures
Authors: Latos-Bielenska A. , Trautmann T. , Vogel W.
Published: May 2008

Most of the techniques used to visualize structures of the synaptonemal complex (SC) are based on specific staining properties or immunocytochemical detection of proteinaceous SC components. The SC is therefore considered to be mostly protein. We have now accomplished visualization of the DNA within the SC by use of the BrdU antibody technique, following BrdU substitution during the last premeiotic S phase. Preparations of mouse meiotic chromosomes were obtained by spreading on a water surface. The DNA content in the SCs, which appeared as light threads, was clearly lower than the DNA content in the surrounding chromatin. At higher magnification, dark, longitudinal structures appeared in these threads. These structures are made up of DNA, which forms the inner part of the lateral elements of the SCs. Within the SCs, DNA is confined mostly to these threads. Thus, DNA staining reveals the same structures already known from protein staining of SCs. The DNA mass surrounding the SCs is often nonhomogeneously distributed along the chromosome axis. The more dense parts appear to be chromomeres. The DNA staining technique described in this paper may therefore be a useful complement to standard protein staining techniques for pachytene chromosomes.
Characterization of chromosomes and localization of the rDNA locus in the aye-aye (Daubentonia madagascariensis)
Authors: Tagle D.A. , Goodman M. , Miller D.A.
Published: May 2008

The karyotype of a prosimian primate, the aye-aye (Daubentonia madagascariensis) is described. Results from a variety of staining methods (Q-, R-, G-, and C-banding, distamycin A/DAPI and methyl-green/DAPI) are reported. Sites of methyla-tion were visualized using antibodies against 5-methylcytosine. Digestion of aye-aye fixed metaphase chromosomes with the restriction endonuclease Haelll produced G-banding. No other restriction enzymes tested produced clear G- or C-banding patterns. Ag-staining of the nucleolar organizer regions (NORs) revealed the location of rDNA sites on the short arms of the smallest pairs of acrocentric chromosomes, 13p and 14p.
Nondisjunction, disturbances in spindle structure, and characteristics of chromosome alignment in maturing oocytes of mice heterozygous for Robertsonian translocations
Authors: Eichenlaub-Ritter U. , Winking H.
Published: May 2008

To correlate the chromosomal constitution of meiotic cells with possible disturbances in spindle function and the etiology of nondisjunction, we examined the spindle apparatus and chromosome behavior in maturing oocytes and analyzed the chromosomal constitution of metaphase Π-arrested oocytes of CD/ Cremona mice, which are heterozygous for a large number of Robertsonian translocation chromosomes (18 heterobrachial metacentrics in addition to two acrocentric chromosomes 19 and two X chromosomes). Spreading of oocytes during prometaphase I revealed that nearly all oocytes of the heterozygotes contained one large ring multivalent, apart from the bivalents of the two acrocentric chromosomes 19 and the X chromosomes, indicating that proper pairing and crossing-over between the homologous chromosome arms of all heterobrachial chromosomes took place during prophase. A large proportion of in vitro-matured oocytes arrested in metaphase II exhibited numerical chromosome aberrations (26.5% hyperploids, 40.8% hypoploids, and 6.1% diploids). In addition, some of the oocytes with euploid chromosome numbers (26.5% of the total examined) appeared to be nullisomic for one chromosome and disomic for another chromosome, so that aneuploidy levels may even be higher than expected on the basis of chromosome counts alone. Although oocytes of the complex heterozygous mice seemed able initially to form a bipolar spindle during first prometaphase, metaphase I spindles were frequently asymmetrical. Chromosomes in the multivalent did not align properly at the equator, centromeres of neighboring chromosomes in the multivalent remained maloriented, and pronounced lagging of chromosomes was observed at telophase I in oocytes obtained from the Robertsonian translocation heterozygotes. Therefore, disturbances in spindle structure and chromosome behavior appear to correlate with the chromosomal constitution in these oocytes and, ultimately, with failures in proper chromosome separation. In particular, reorientation appears to be a rare event, and malorientation of chromosomes may remain uncorrected throughout prometaphase, as we could not find many typical metaphase I stages in heterozygotes. This, in turn, could be the basis for malsegregation at anaphase and may ultimately induce a high rate of nondisjunction and aneuploidy in the oocytes of CD/Cremona mice, leading to total sterility in heterozygous females.
In situ hybridization to human chromosome 1 of a cDNA probe for the gene encoding the basement membrane heparan sulfate proteoglycan (HSPG)
Authors: Wintle R.F. , Kisilevsky R. , Noonan D. , Duncan A.M.V.
Published: May 2008

A mouse partial cDNA clone of the heparan sulfate proteoglycan gene, an important component of basement membranes, has been mapped to human chromosome 1, band p 36.1, by in situ hybridization. No secondary sites of hybridization were observed.
Localization of mouse melanoma growth stimulatory activity gene (Mgsa) between Afp and Gus on chromosome 5 using interspecific backcross mice
Authors: Seldin M.F. , Martinez L. , Howard T.A. , Naylor S.L. , Sakaguchi A.Y.
Published: May 2008

Melanoma growth stimulatory activity (Mgsa) is a polypeptide mitogen and a possible autocrine growth factor for melanoma and other tumor cells. A restriction fragment length variant of Mgsa was followed in interspecific backcross mice. Mgsa was localized between Afp and Gus on mouse chromosome 5, distal to known loci affecting skin pigmentation.
Localisation of neurone-specific enolase (ENO2) to 12p13
Authors: Craig S.P. , Day I.N.M. , Thompson R.J. , Craig I.W.
Published: May 2008

We have localised the human cDNA for neurone-specific enolase (EN02) to chromosome region 12p13 by in situ hybridisation. Two additional smaller peaks of hybridisation to specific chromosomal subregions were observed. That on chromosome lp36 probably represents cross-hybridisation to the locus for nonneuronal enolase (ENOl), which has been previously localised to this chromosome and with which EN02 shares homology. A further gene for a member of the enolase family may be responsible for the hybridisation to chromosome 17.
Localization of the human luteinizing hormone/choriogonadotropin receptor gene (LHCGR) to chromosome 2p21
Authors: Rousseau-Merck M.F. , Misrahi M. , Atger M. , Loosfelt H. , Milgrom E. , Berger R.
Published: May 2008

Probes corresponding to human and porcine LH (luteinizing hormone) receptor cDNA were used for in situ hybridization to human chromosomes. This allowed us to assign the LH receptor gene to chromosome 2p21.
Localization of human thyrotropin receptor gene to chromosome region 14q31 by in situ hybridization
Authors: Libert F. , Passage E. , Lefort A. , Vassart G. , Mattei M.-G.
Published: May 2008

The gene for human thyrotropin receptor (TSHR) was assigned to chromosome J4, band q31, by in situ hybridization, using a probe for TSHR
Assignment of the human calpastatin gene (CAST) to chromosome 5 at region q14→q22
Authors: Inazawa J. , Nakagawa H. , Misawa S. , Abe T. , Minoshima S. , Fukuyama R. , Maki M. , Murachi T. , Hatanaka M. , Shimizu N.
Published: May 2008

The human calpastatin gene (CAST) was assigned to chromosome 5 by spot-blot hybridization analysis with flow-sorted chromosomes, and it was further sublocalized to bands 5q14→q22 using in situ hybridization to metaphase chromosomes
Mapping the gene for murine T-cell growth factor, Il-2 to bands B-C on Chromosome 3 and for the α chain of the IL2-receptor, Il-2ra, to bands A2–A3 on Chromosome 2
Authors: Webb G.C. , Campbell H.D. , Lee J.S. , Young I.G.
Published: May 2008

Il-2, the gene coding for the cytokine IL2 in the mouse, has been localized by in situ hybridization to bands 3B or 3C on Chromosome 3, where it joins five other genes that also map to 4q in humans. The Il–2 probe also produces a small, secondary grain peak on Chromosome 11, in the vicinity of band 11A5, the significance of which has not yet been determined. The gene for the α chain of the IL2 receptor in the mouse, Il-2ra, localizes to bands 2A2 or 2A3 on Chromosome 2. This is the first assignment of a gene located on chromosome 10 in humans to Chromosome 2 in the mouse.
Localization of the mouse Mcf-2 (Dbl) protooncogene within a conserved linkage group on the mouse X chromosome
Authors: Grant S.G. , Mattei M.-G. , Galland F. , Stephenson D.A. , Keitz B.T. , Birnbaum D. , Chapman V.M.
Published: May 2008

A mouse cDNA probe homologous to the human MCF2 transforming sequence has been identified and partially cloned, and is used here to localize the gene on the mouse X chromosome. The human gene has been physically mapped to within 60 kb of the gene for coagulation factor IX, within a large conserved linkage group between the mouse and human genomes which extends from HPRT to G6PD on the X chromosomes of both mammalian species. In situ hybridization of the mouse Mcf-2 probe onto mouse metaphase chromosomes indicates that this gene lies in the same region of the X chromosome as Cf-9, the mouse gene for coagulation factor IX. Moreover, segregation of species-specific genomic DNA polymorphisms for Mcf-2 and Cf-9 in a total of 203 individuals derived from two large interspecific mouse backcross populations (which are also segregating for 17 other X-linked molecular markers) demonstrates that the mouse genes are separated by only 0.5 ± 0.5 cM. Despite this short distance we were able to order Mcf-2 and Cf-9 relative to one another and other genes in this region. The mouse gene order Hprt – Cf-9 – Mcf-2 – G6pd predicts a similar ordering of genes on the human X chromosome, a gene order which has only recently been demonstrated by physical mapping. Thus, the map location and linkage relationships of the Mcf-2 gene are similar in man and mouse, and this unique protooncogenic locus is part of a conserved linkage group on the mammalian X chromosome.
No induction of interchromosomal effect in male meiosis of Chinese hamsters with reciprocal translocations
Authors: Sonta S. , Kitayama K.
Published: May 2008

Chinese hamsters from five strains with reciprocal translocations, T(l;3)7Idr, T(l;3)8Idr, T(l;2)9Idr, T(7;9)16Idr, and T(l;5)17Idr, and a karyotypically normal strain, CHS/Idr, were used to look for an interchromosomal effect by chromosomal analysis of meiotic cells and one-cell embryos. The frequencies of nondisjunction at first meiosis in five normal ( + / + ) males, calculated by doubling the number of hyperhaploid cells, ranged from 0.43% to 1.33%, and there was no significant difference in frequency among individuals. On the other hand, the frequency of hyperhaploid cells in males heterozygous for each translocation ranged from 3.0% to 11.8%, and the frequency of hyperhaploid cells with an extra translocation-unrelated chromosome ranged from 0.2% to 0.4%, which is no different from that estimated from scoring of +/+ males at the second meiotic metaphase. In one-cell embryos from crosses between karyotypically normal females and male heterozygotes for T(l;2)9Idr and T(7;9)16Idr, 1.1% and 0.5% of embryos had an extra translocation-unrelated chromosome. Compared with the control, the frequency of meiotic nondisjunction showed no increase in male heterozygotes for the reciprocal translocations. Therefore, the results suggest that multivalents and rearranged chromosomes existing at first and second meiosis in male Chinese hamsters exert no influence on segregation of normal bivalents and chromosomes unrelated to the rearrangements.
The Chinese hamster cell mutant V-H4 is homologous to Fanconi anemia (complementation group A)
Authors: Arwert F. , Rooimans M.A. , Westerveld A. , Simons J.W.I.M. , Zdzienicka M.Z.
Published: May 2008

V-H4, a mitomycin C (MMC)-sensitive Chinese hamster cell mutant, is phenotypically very similar to Fanconi anemia (FA) cells. Genetic complementation analysis shows that V-H4 belongs to the same complementation group as FA group A cells. Proliferating hybrid cell lines obtained after fusion of V-H4 with normal or FA group B cells show an increased resistance to MMC. Absence of complementation was noted in V-H4 × FA group A hybrid cell lines. This was shown not to be due to the absence of a specific human chromosome. The V-H4 mutant represents the first rodent mutant that is genotypically similar to FA complementation group A cells.
Localization of the human T-cell receptor gamma locus (TCRG) to 7p14→p15 by in situ hybridization
Authors: Bensmana M. , Mattei M.G. , Lefranc M.-P.
Published: May 2008

The human T cell receptor gamma locus (TCRG) has previously been localized on chromosome 7 at band 7p15. In situ hybridization of a TCRG-specific probe allowed us to map the locus at 7p14→p15. These data confirm the previous localization and are in agreement with the molecular characterization of an inversion of chromosome 7, inv(7) (p14q35) which involves the TCRG locus.
Localization of the dihydrolipoamide branched-chain transacylase gene (DBT) of the human branched-chain keto acid dehydrogenase complex to chromosome 1
Authors: Lau K.S. , Eddy R.L. , Shows T.B. , Fisher C.W. , Chuang D.T. , Cox R.P.
Published: May 2008

The gene coding for the transacylase subunit (DBT) of the human branched-chain keto acid dehydrogenase complex was localized to chromosome 1 by probing panels of human × mouse chromosome hybrids with an E2 cDNA amplified by the polymerase chain reaction. Additional data with two hybrids containing chromosome 1 fragments suggest that the DBT gene is located on the short arm (1pter→p21) of the chromosome.
A DNA sequence that is present in both sexes of Artiodactyla is repeated on the Y chromosome of cattle, sheep, and goats
Authors: Matthews M.E. , Reed K.C.
Published: May 2008

We have cloned a 307-bp Sau1Al fragment of DNA from the bovine male genome by deletion enrichment. Although a single-copy homolog is present in the female cattle genome, the sequence (BRY.1) is repeated at a moderate and variable frequency only in males. This pattern occurs too in sheep and goats, but BRY.l is found in equal amounts in both sexes of fallow deer and pigs, approximating single copy. The conservation of a homologous sequence over millions of years and its repetition exclusively on the Bovidae Y chromosome raise interesting questions concerning the origin, evolution, and possible function of this unusual element.
The high-resolution GTG-banding pattern of pig chromosomes
Authors: Yerle M. , Galman O. , Echard G.
Published: May 2008

A high-resolution GTG-banded karyotype of the pig was obtained after methotrexate-induced cell synchronization. A diagrammatic representation of the banding pattern at the 539-band level is presented.
Localization of the gene encoding insulin-like growth factor I on mouse Chromosome 10
Authors: Taylor B.A. , Grieco D.
Published: May 2008

The peptide hormone, insulin-like growth factor I (IGF-I), is a major determinant of growth in mammals, and also plays a role in differentiation of adipocytes and other cells (Van Wyk, 1984). Although IGF-I is synthesized in many cell types, the liver appears to be the principal organ in which IGF-I is synthesized in response to pituitary growth hormone. In mice, there is a spurt of IGF-I synthesis in liver at about three weeks of age. In human pygmies, the absence of a growth spurt at adolescence is associated with the absence of an increase in serum levels of IGF-I (Merimee et al., 1981). Thus deficiency of IGF-I may be the primary determinant of short stature in pygmies and in other isolated cases of growth hormone resistant dwarfism. Although the murine Igf-1 locus has not been assigned to a chromosome, the human homolog (IGF1) has been mapped to chromosome region 12q22→q24.1 (Francke et al., 1986). Since there appears to be extensive homology between this human chromosomal segment and the distal part of murine Chromosome 10, linkage to this chromosome was suspected. Because the growth deficient mutation of the mouse, pygmy (pg), has also been mapped to Chromosome 10 (Falconer and Isaacson, 1965), we were interested in localizing Igf-1 in order to investigate the possibility thatpg might be allelic to Igf-1. We show that the Igf-1 locus is located in the central part of Chromosome 10, a considerable distance from pg.
Alul and Haelll restriction enzyme banding patterns of Macaca fuscata and Cercopithecus aethiops sabaeus chromosomes
Authors: Stuppia L. , Romagno D. , Palka G. , Guanciali Franchi P. , Parruti G. , Calabrese G. , Bianchi U.
Published: May 2008

Alul and Haelll restriction endonuclease banding patterns were analyzed in Macacafuscata and Cercopithecus aethiops sabaeus chromosomes. AluI produced C-negative bands in both species of monkeys, while Haelll induced the appearance of C-negative bands on Macaca chromosomes and of simultaneous G + C bands on Cercopithecus metaphases.
A repeating unit of the DYZ1 family on the human Y chromosome consists of segments with partial male-specificity
Authors: Nakagome Y. , Nagafuchi S. , Seki S. , Nakahori Y. , Tamura T. , Yamada M. , Iwaya M.
Published: May 2008

An average-sized human Y chromosome contains about 3,000 copies of the repeating DNA family DYZ1. A major repeating unit of the family, pHYlO, has been cloned and an entire 3,564-bp sequence has already been determined by Nakahori et al. (1986). In the present study, pHYlO was divided into six consecutive segments, A to F, which were independently amplified by the PCR technique to see if they were strictly male-specific. pHYlO appears to consist of segments of various male-specificity. The B segment was apparently male-specific; however, the use of additional techniques (Southern-blot analysis or second PCR amplification in combination with the standard PCR) revealed homologous sequences in some females. None of the six segments of pHYlO may be male-specific in a strict sense. Different segments appear to be conserved during evolution to different extents. The 323-bp E segment appears to be the least conserved and to be responsible for the generation of most variations within the DYZ1 family.
Achiasmatic sex chromosomes in Pitymys duodecimcostatus: mechanisms of association and segregation
Authors: Carnero A. , Jiménez R. , Burgos M. , Sánchez A. , Díaz de la Guardia R.
Published: May 2008

The meiotic behavior of the sex chromosomes of Pitymys duodecimcostatus was studied by electron microscopy of whole-mount synaptonemal complex preparations. The results established that the sex chromosomes of this species are achiasmatic and remain unassociated throughout meiotic prophase I in most spermatocytes. In other cells, nonspecific association of the X and Y occurred by means of filamentous bridges. Pitymys duodecimcostatus represents an additional example of a mammalian species lacking a homologous pairing segment in its sex chromosomes and extends current knowledge about this controversial subject. In this regard, we suggest that sex-chromosome association is a characteristic that probably followed different evolutionary paths in different mammals, leading to loss of the homologous segment in some species and its conservation in others. It is also suggested that in P. duodecimcostatus, and probably in many other species as well, three mechanisms may act in concert to permit joining of the X and Y chromosomes during meiotic prophase, and, consequently, to ensure proper segregation during anaphase I: (1) joining of the sex-chromosome axes at their ends to the nuclear membrane, (2) formation of fibrillar structures to hold the sex chromosomes together, and (3) cohesiveness due to sex-vesicle formation.
Random/nonrandom X-chromosome inactivation in Nesokia indica: possible influence of heterochromatin
Authors: Thelma B.K. , Tewari R. , Juyal R.C. , Rao S.R.V.
Published: May 2008

Five types of X chromosomes with different amounts of heterochromatin have been observed in Nesokia indica, the Indian mole rat. They have been found in both mosaic and non-mosaic individuals. The influence, if any, of heterochromatin on the kinetics of X-chromosome DNA replication was evaluated in bone marrow cells and peripheral blood lymphocytes of Nesokia females with variant X chromosomes. In bone marrow cells of nonmosaic females a random X-chromosome inactivation (XCI) pattern was observed, except when there was a total loss of heterochromatin from the variant X chromosome, resulting in predominantly early replication. A nonrandom pattern was observed, however, in blood and bone marrow cells of all individuals with mosaic genotypes. In these females the X chromosome with the lesser amount of heterochromatin was predominantly the active one. The amount of heterochromatin per se or, more likely, specific sequences contained in the heterochromatic region seem to influence the XCI pattern in a cis-acting manner. The observations also seem to support a process of cell selection in individuals with variant X chromosomes.
Characterization of a B-lymphocyte t(2;14) (p11;q32) translocation from an ataxia telangiectasia patient conferring a proliferative advantage on cells in vitro
Authors: Metcalfe J.A. , Heppell-Parton A. , McConville C.M. , Taylor A.M.R.
Published: May 2008

Patients with the recessively inherited disorder ataxia telangiectasia (AT) are particularly prone to the development of both B-cell and T-cell tumours. Specific translocations involving T-cell gene rearrangements and an unknown locus 3’ of IGH have been described in AT T-cell clone and tumour cells. We describe here a t(2;14)(p11;q32) translocation which was observed in nonmalignant short-term-cultured B lymphocytes from an AT patient. In vivo, the clone of cells grew from 1 % to 6% of the total cell population over a period of 2 yr. Clonal translocations may therefore be associated with AT B cells, as well as AT T cells. B lymphocytes were transformed with Epstein-Barr virus, and the t(2;14) translocation cell was cellularly cloned. Using Southern filter analysis and in situ hybridisation to define more clearly the positions of the breakpoints, we show that the translocation at 14q32 involves a deletion within the IGH chain gene of at least J1, J2, DQ52, and sequences 1.5 kb 5’ of DQ52 and that the breakpoint is either adjacent to the non-deleted JH sequences or upstream of these sequences, within the D or V regions, but proximal to all members of the VHII family of genes. The breakpoint at 2p11 is outside and proximal to IGK with respect to the centromere in an unknown gene. Sub-lines with an initially low proportion of translocation cells eventually became monoclonal in vitro for these cells. This suggests they have a growth advantage in vitro.
The gene for mannose-binding protein maps to chromosome 10 and is a marker for multiple endocrine neoplasia type 2
Authors: Schuffenecker I. , Narod S.A. , Ezekowitz R.A.B. , Sobol H. , Feunteun J. , Lenoir G.M.
Published: May 2008

Human mannose-binding lectin (MBL) is a serum protein which appears to function as an opsonin in first line host defense. In situ hybridization studies assign the human MBL gene to chromosome 10q11.2→q21. A restriction fragment length polymorphism (RFLP) was found using Taql with a 0.8-kb cDNA probe for MBL (probe 48–11), yielding heterozysity in 34% of individuals tested. Using this biallelic RFLP, linkage analysis of 30 families confirms the assignment of MBL to the region of multiple endocrine neoplasia, type 2a (MEN2A) with a maximum lod score of 7.54 at a recombination fraction of 0.00 (males) and 0.097 (females). The presence of two crossovers between MEN2A and MBL in these families indicates that a defect of MBL itself is not the cause of the hereditary thyroid cancer syndrome. The addition of MBL to the genetic map of the pericentromeric region of chromosome 10 should prove useful for improved localization of the MEN2A mutation.
Epidermal type I transglutaminase (TGM1) is assigned to human chromosome 14
Authors: Polakowska R.R. , Eddy R.L. , Shows T.B. , Goldsmith L.A.
Published: May 2008

Human epidermal type I transglutaminase coexists in keratinocytes with another cross-linking enzyme, tissue type II transglutaminase. There are at least five different forms of the enzyme in mammals. Gene mapping studies allowed us to determine whether the different transglutaminases are products of the same gene or separate genes. The gene encoding factor XIII subunit a transglutaminase (F13A1) was previously assigned to human chromosome 6, p24→p25. We demonstrate using somatic cell hybrids that the human epidermal type I transglutaminase gene (gene symbol is designated TGM1) is located on human chromosome 14, providing evidence that at least two human transglutaminases are encoded by separate genes.
Heterochromatin and karyotype reorganization in fish of the family Anostomidae (Characiformes)
Authors: Galetti Jr. P.M. , Mestriner C.A. , Venere P.C. , Foresti F.
Published: May 2008

Mitotic chromosomes of four fish species of the family Anostomidae, belonging to the genera Leporinus, Leporellus, and Schizodon, were studied. With 2n = 54 meta- and submetacentric chromosomes, this family appears to be characterized by marked karyotypic stability. Although perceptible differences exist, mainly in the amount of constitutive heterochromatin present in the chromosomes of these species, these differences do not affect the structure and/or size of these chromosomes. Chromatin substitutions and/or modifications may have led, in one direction, to an increase in heterochromatin in some species and, in the opposite direction, to heterochromatin reduction in others. Whether these changes are accompanied by changes in the amount of euchromatin in the chromosomes is an open question. The nucleolar organizer regions, which may be located on different chromosomes in the various species, may also be indicators of reorganization of these karyotypes.
Mapping of the silver fox genes: assignments of the genes for ME1, ADK, PP, PEPA, GSR, MPI, and GOT1
Authors: Nesterova T.B. , Rubtsov N.B. , Zakian S.M. , Matveeva V.G. , Graphodatsky A.S.
Published: May 2008

Evidence is presented for the assignment of seven fox genes on the basis of the segregation data for chromosomes and enzymes of fox × Chinese hamster somatic cell hybrids. The chromosomal loci of the following enzyme genes were determined: ME1, VFU1; ADK and PP, VFU4; PEPA, VFU5; GSR, VFU7; and MPI and GOT1, VFU15. The localization of these genes now extends the fox genetic map to 22 mapped genes. Based on comparative analysis of mammalian genetic maps, karyotype evolution in Carnivora is discussed.
Detection of trisomy 8 in hematological disorders by in situ hybridization
Authors: Kibbelaar R.E. , van Kamp H. , Dreef E.J. , Wessels J.W. , Beverstock G.C. , Raap A.K. , Fibbe W.E. , den Ottolander G.J. , Kluin P.M.
Published: May 2008

An alphoid repetitive DNA (D8Z2) probe specific for the pericentromeric region of chromosome 8 was used to detect extra copies of chromosome 8 in bone marrow cells obtained from 10 patients with hematological disorders and five controls. Numerical aberrations of chromosome 8 were established by conventional banding techniques. Trisomy 8 was found in four patients with myelodysplastic syndrome (MDS) and three with acute myeloid leukemia (AML). Three additional patients with MDS exhibited an extra chromosome 8 in only one metaphase. In five of the seven trisomy cases, the presence of the trisomy 8 clone was confirmed by in situ hybridization (ISH). In one case of AML with trisomy 8, detected by GTG-banding, no significant numbers of cells containing three spots were found using the alphoid repetitive probe; however, hybridization with a chromosome 8-specific library revealed that the alleged extra chromosome 8 was a translocation chromosome containing only the long arm of chromosome 8. Due to a lack of material, it was not possible to achieve optimal ISH results on the trisomy 8 bone marrow cells of patient 7. In the three MDS patients with a single trisomy 8 metaphase, a slight, albeit significant, increase of trisomy 8 interphase cells was found with ISH. We conclude that this probe is useful for cytogenetic studies. Moreover, ISH, in general, is a powerful tool for precise classification of chromosomal aberrations and can also contribute significantly to the clinical evaluation of patients with hematological disorders.
Telomeric associations involving Yq12 in a lymphoblastoid cell line
Authors: Abruzzo M.A. , Miller J.A. , Singer V.L.
Published: May 2008

A number of apparent telomeric associations/ fusions (TAs) involving Yq12 were observed in a lymphoblastoid cell line (GM6892A) established from a fragile-X-negative, phenotypically normal male with the fragile X gene mutation. The TAs were seen when these cells were grown for an extended period of time in medium 199, which is deficient in thymidine and folic acid. Because the low thymidine and folic acid condition of medium 199 is known to induce chromosome and chromatid gaps and breaks at folate-sensitive fragile sites, other fragile site-induction regimes were examined to determine if the TAs seen in GM6892A were due to a fragile site in the Yq12 band. No TAs were seen with any of the other regimes that were tried.
Somatic cell mapping of bovine clathrin light chain genes: identification of a new bovine synthenic group
Authors: Gallagher D.S. , Threadgill D.W. , Jackson A.P. , Parham P. , Womack J.E.
Published: May 2008

Two bovine DNA probes (LCa and LCb) complementary to the clathrin light chain genes were hybridized to DNAs from bovine hamster hybrid somatic cell lines retaining different combinations of bovine chromosomes. Concordancy of retention of the clathrin genes was compared to existing syntenic data for the domestic cow. LCb, identified a single locus, CLTB, concordant with the genes encoding bovine anti-Müllerian hormone (AMH) and bovine osteonectin from bovine syntenic group U22. LCa recognized two loci, CLTAL1 from a previously unidentified bovine syntenic group, U25, and CLTAL2 which is concordant with GGTB2, a gene marker for bovine syntenic group U18.
Chromatin diminution and chromosome elimination in four Japanese hagfish species
Authors: Nakai Y. , Kubota S. , Kohno S.
Published: May 2008

Cytogenetic examination of four Japanese hagfish species belonging to the order Myxinida (Eptatretus okinoseanus, E. burgeri, Paramyxine atami, and Myxine garmani) revealed differences in chromosome number between germ cells (spermatocytes and spermatogonia) and somatic cells (liver, blood, gill, and kidney). The differences in chromosome number between spermatogonia (54, 52, 48, and 16) and somatic cells (34, 36, 34, and 14) were 20, 16, 14, and 2 in E. okinoseanus, E. burgeri, P. atami, and M. garmani, respectively. The amount of DNA in a somatic cell (2C) relative to that in a germ cell (2C) averaged 54.6% (E. okinoseanus type A), 44.9% (E. okinoseanus type B), 79.1 % (E. burgeri), 60.0% (P. atami), and 70.2 % (M. garmani). These results clearly indicate that chromosome elimination takes place during early cleavage in the four hagfish species of Myxinida living in Japanese waters, except in the ancestral germline cells. C-banding of metaphase chromosome preparations of germline and somatic cells from each hagfish species revealed that the C-band-positive chromatin in the ancestral somatic cells had been almost completely eliminated. Three patterns of elimination of this chromatin are discussed.