bluuebunny/crossref_metadata_2025 huggingface dataset:
A human lymphoblastoid cell line from the offspring of a brother-sister mating
Authors: Azen E.A. , Karn R.C. , Pauli R.M.
Published: May 2008

A human lymphoblastoid cell line was established from an individual who was the offspring of a brother-sister incestuous mating. Many genes in this cell line are homozygous, including those of the HLA system.
An improved method for G-banding chromosomes after in situ hybridization
Authors: Cannizzaro L.A. , Emanuel B.S.
Published: May 2008

We report a method for producing high-resolution G-bands on chromosomes of normal and neoplastic human cells after hybridization of 3H-labeled probes to the chromosomes and after autoradiography.
G-banding evidence for a conserved complement in the Marsupialia
Authors: Rofe R. , Hayman D.
Published: May 2008

G-banding data are presented for a wide range of Australian marsupial species and one South American species, all of which have 2n= 14. The chromosome banding pattern in each of these species is very similar. Variations between species can be explained by structural changes internal to individual chromosomes. This evidence favors the hypothesis of a conserved complement common to both Australian and American marsupials and underlies the dominant role of chromosome fission in the evolution of this group.
Chromosome banding techniques for morphologically classified cells
Authors: Knuutila S. , Keinänen M.
Published: May 2008

This report describes staining techniques for chromosome banding and sister chromatid exchanges (SCEs) suited to a method that allows simultaneous analysis of cell morphology and karyotype. Mitotic cells are first identified by either cytochemical staining or immunologic methods. The preparations are then destained and treated with acid fixative. For G- and C-banding, the cells are incubated overnight at room temperature in Sørensen buffer and then stained with Giemsa. To demonstrate SCEs, the cells are fluorescent stained before being stained with Giemsa.
Different sister chromatid exchange rates in XX and XY cells of a pair of human chimeric twins
Authors: Wulf H.C. , Niebuhr E.
Published: May 2008

To explore the influence of sex on sister chromatid exchange (SCE) level, a pair of chimeric twins was examined for differences in SCE frequency between the XX and XY cells present in each individual. By this method, the influence of possible differences in environmental exposure was eliminated. SCE levels were varied by growing the cells in media containing 0, 1.3 × 10–7, or 6.5 × 10–7 M melphalan. XX cells showed a higher SCE count than XY cells. This difference increased with increasing SCE level and ranged from 5.4% to 7.8% (P = 0.0003) of the SCE counts. Only about 2% of the difference could be explained by the higher amount of DNA present in the XX cells than in the XY cells. In this case XX cells seemed to be more sensitive to SCE-inducing agents than XY cells.
Regional mapping of cKi-ras proto-oncogene on mouse chromosome 6 by in situ hybridization
Authors: Cahilly L.A. , George D.L.
Published: May 2008

We have used in situ hybridization techniques to determine the subchromosomal location of the mouse cKi-ras protooncogene. The data confirm the assignment of cKi-ras to mouse chromosome 6 and provide evidence that the gene maps to the distal portion of this chromosome, in bands 6F3→G3.
Chromosomal evolution in Malagasy lemurs
Authors: Rumpler Y. , Ishak B. , Warter S. , Dutrillaux B.
Published: May 2008

The karyotypes of three Lepilemuridae species, Lepilemur ruficaudatus, L leucopus, and L septentrionalis, are described and compared. An almost complete analogy of chromosome banding is exhibited. Several complex chromosomal rearrangements, especially end-to-end translocations, have occurred in the evolution of these species. The chromosomal data indicate that the species studied are well separated. In addition, their common chromosomal characters show that they constitute a clearly distinct family among the lemurs.
Correlation between X-chromosome inactivation and cell differentiation in female preimplantation mouse embryos
Authors: Sugawara O. , Takagi N. , Sasaki M.
Published: May 2008

By means of a cytological method involving BrdU incorporation and acridine orange fluorescence staining in combination with embryo manipulation, we studied X-chromosome activity in female preimplantation mouse embryos with special reference to the correlation between X-chromosome inactivation and cell differentiation. There was no sign of asynchronous replication between the two X chromosomes from the one-cell to intermediate blastocyst stage. The allocyclic X chromosome, first detected in late blastocysts, was paternal in origin, mostly replicating early in the S phase and limited to the trophectoderm. Subsequent X-chromosome inactivation occurring in the primary endoderm was also characterized by the involvement of the paternal X and early replication. Both X chromosomes continued to replicate synchronously in the embryonic ectoderm or epiblast at this stage. It was evident that overt cell differentiation preceded the appearance of the asynchronously replicating X chromosome in the trophectoderm and primary endoderm. This finding seems to support the view that cell differentiation is an important correlate of X-chromosome inactivation.
Localization of the human myelin basic protein gene (MBP) to region 18q22→qter by in situ hybridization
Authors: Saxe D.F. , Takahashi N. , Hood L. , Simon M.I.
Published: May 2008

A restriction endonuclease fragment derived from a cloned portion of human genomic DNA corresponding to the myelin basic protein gene has been used to map the position of this gene by in situ hybridization to human metaphase chromosomes. Ten percent of the radioactively labeled sites observed were on chromosome 18. Eighty-four percent of the grains on chromosome 18 were located within the region corresponding to 18q22→qter. This represents a greater than 10-fold increase in labeling at this position over the background grain distribution found along all of the other chromosomes.
Aging and aneuploidy: evidence for the preferential involvement of the inactive X chromosome
Authors: Abruzzo M.A. , Mayer M. , Jacobs P.A.
Published: May 2008

It has been known for some time that there is an association between chronological aging and X-chromosome aneuploidy in peripheral blood lymphocyte cultures from females. In an attempt to elucidate the mechanism of X-chromosome aneuploidy in aging females, we used a BrdU late-labeling technique to determine the X-inactivation pattern in 45, X and 47, XXX lymphocytes of older women. In 50 of 58 X-aneuploid cells the inactive X chromosome was missing or extra. This implies that either the inactive X has a special propensity for mitotic errors or mitotic errors occur at random but subsequent selection is less stringent against cells with a missing or additional inactive X chromosome than against aneuploid cells involving the active X chromosome. Evidence is presented in favor of the former hypothesis.
Double synchronization of human lymphocyte cultures: selection for high-resolution banded metaphases in the first and second division
Authors: Rønne M.
Published: May 2008

The present report describes a double synchronization technique that selects for first- and second-division metaphases in human lymphocyte cultures. The technique ensures high mitotic indices without elaborate handling of cultures. Combined with appropriate band induction, this technique provides a high yield of uniform metaphases with well-defined high-resolution banding.
Regional assignments of eight genes on chromosome 2 in the American mink
Authors: Zhdanova N.S. , Gradov A.A. , Rubtsov N.B. , Pack S.D. , Serov O.L.
Published: May 2008

Chromosomal rearrangements involving mink chromosome 2 in mink-Chinese hamster and mink-mouse hepatoma somatic hybrids were identified. By means of these rearrangements, we assigned the genes for HK1, GOT1, and PP to 2pter→p22, those for PGD, PGM1 and ENO1 to 2q24.4→qter, and that for NP and ADK to 2pter→p11.1.
Chromosomal evolution in the Malagasy Carnivora
Authors: Couturier J. , Razafimahatratra E. , Dutrillaux B. , Warier S. , Rumpler Y.
Published: May 2008

Comparison of the karyoptypes of Cryptoprocta ferox Fossa fossana, Galidia elegans elegans, G. e. dambrensis and Mungotictis decemlineata permitted the reconstruction of an ancestral Malagasy Carnivora karyotype. This was compared with the ancestral karyotype of non-Malagasy Carnivora, which allowed us to speculate on the phylogeny of Malagasy and non-Malagasy Carnivora. Assuming that Africa and Madagascar separated during the Jurassic or Cretaceous, the hypothesis of a polyphyletic origin of the Malagasy Carnivora still appears tenable, but the hypothesis that the Carnivora emerged before the isolation of Madagascar agrees better with our cytogenetic results.
Assignment of the human fibronectin structural gene to chromosome 2
Authors: Prowse K.R. , Tricoli J.V. , Klebe R.J. , Shows T.B.
Published: May 2008

A cloned human cDNA probe for fibronectin (FN) containing 1.3 kb of the human FN coding region has been used to determine the chromosome that encodes the structural gene in human-mouse somatic cell hybrids. The results show that human chromosome 2 encodes the FN structural gene.
Expression of heterochromatin by restriction endonuclease treatment and distamycin A/DAPI staining of Indian muntjac (Muntiacus muntjak) chromosomes
Authors: Babu A. , Verma R.S.
Published: May 2008

The constitutive heterochromatin of the Indian muntjac (Muntiacus muntjak) was examined following digestion with various restriction endonucleases (AluI, Haelll, HinfI, and MboI), as well as by selective fluorescence staining with distamycin A plus 4’-6-diamidino-2-phenylindole. Distinct areas within the C-bands were found to have characteristic staining patterns which were more conspicuous in the sex chromosomes. Two dot-like structures resistant to AluI were found in the X and Y1 chromosomes in the same position as the nucleolus organizer regions.
Meiotic studies of Robertsonian heterozygotes from natural populations of the common shrew, Sorex araneus L.
Authors: Searle J.B.
Published: May 2008

Adult male common shrews, both Robertsonian heterozygotes and homozygotes, were collected from Oxford and elsewhere in Britain. In both simple Robertsonian heterozygotes and Robertsonian heterozygotes with monobrachial homology, regular chain configurations were observed at meiosis I; only 1–2% were incomplete such that univalents were observed. On the average, there was one chiasma per chromosome arm among those that displayed Robertsonian variation, including both chain configurations and bivalents. According to one hypothesis, a single chiasma per chromosome arm may facilitate proper disjunction of chain trivalents of simple Robertsonian heterozygotes. Based on metaphase II counts, anaphase I nondisjunction frequency can be estimated as 1.0% per heterozygous individual and 0.7% per heterozygous arm combination.
Two subsets of human alphoid repetitive DNA show distinct preferential localization in the pericentric regions of chromosomes 13, 18, and 21
Authors: Devilee P. , Cremer T. , Slagboom P. , Bakker E. , Scholl H.P. , Hager H.D. , Stevenson A.F.G. , Cornelisse C.J. , Pearson P.L.
Published: May 2008

We have isolated and characterized two human middle repetitive alphoid DNA fragments, L1.26 and L1.84, which localize to two different sets of chromosomes. In situ hybridization revealed both repeats to have major and minor binding sites on the pericentric regions of several chromosomes. Probe L1.26 maps predominantly to chromosomes 13 and 21. Probe L1.84 locates to chromosome 18. Minor hybridization sites for both probes include chromosomes 2, 8, 9, and 20; in addition, L1.26 revealed minor sites on chromosomes 18 and 22. The binding to these sites strongly depends on hybridization conditions. In Southern blot hybridizations to total human DNA, both L1.26 and L1.84 give the same ladder pattern, with a step size of 170 bp, indicating their presence as tandem repeats, but with different band intensities for each probe. The chromosome-specific nature of particular multimers was confirmed by Southern blot analyses of a human-rodent hybrid cell panel. We conclude that L1.26 and L1.84, with their related sequences, constitute subfamilies of alphoid DNA that are specific for subsets of chromosomes and, in some cases, possibly even for single chromosomes.
Consequences of polyspermy in man
Authors: Angell R.R. , Templeton A.A. , Messinis I.E.
Published: May 2008

Polyspermy occurs with a frequency of about 12% under some hormonal regimens currently being used for in vitro fertilization and embryo transfer. Oocytes with three pronuclei usually show normal cleavage and are morphologically indistinguishable from embryos produced by normal fertilization. Chromosome studies and DNA measurements on dispermic embryos show that about one-half are triploid, the others having either a normal diploid chromosome complement or a severely depleted chromosome complement. The evidence suggests that these errors must arise at the first mitotic division of the oocyte. Aberrant spindle formation is implicated.
The African Mus genus, an example of karyotypic homogeneity: cytogenetic study of Mus minutoides/musculoides (Ivory Coast), M. setulosus (Central African Republic), and M. mattheyi (Burkina Faso)
Authors: Jotterand-Bellomo M.
Published: May 2008

Eight Mus minutoides/musculoides from the Ivory Coast, eight M. setulosus from the Central African Republic, and seven M. mattheyi from Burkina Faso were analyzed cytogenetically. The results obtained were compared with those from M. setulosus of the Ivory Coast and M. oubanguii and M. minutoidesi musculoides of the Central African Republic in order to study the problem of interspecific phyletic relationships in the African Mus genus. Several data proved to be interesting. First, the centric translocation of the sex chromosomes, which characterizes all TR-type African mice, is species-specific in regard to the autosomal pair involved. Second, the almost total identity of the karyotype of M. mattheyi with the presumed ancestral karyotype confirms the hypothesis that 36 acrocentric chromosomes represent the ancestral karyotype of African mice. Third, intraspecific variability of heterochromatic zones in M. setulosus may represent a step in the isolation of a future new species. Finally, our results reveal a nearly perfect homology of the chromosome arms between the four species studied; this suggests a remarkable karyotypic homogeneity in the African Mus genus.
Regional localization of 18 human X-linked DNA sequences
Authors: Riddell D.C. , Wang H.S. , Beckett J. , Chan A. , Holden J.J.A. , Mulligan L.M. , Phillips M.A. , Simpson N.E. , Wrogemann K. , Hamerton J.L. , White B.N.
Published: May 2008

A series of human probes with unique sequences has been isolated from a recombinant phage library constructed with DNA obtained from a human-hamster hybrid cell line. This cell line contained the X chromosome as the only human component. For 18 of these probes, a human X-chromosome origin has been confirmed and they have been regionally assigned by a combination of techniques: (1) dosage studies utilizing DNA from human fibroblasts carrying X-chromosome duplications and deletions; (2) the presence or absence of hybridization to digested DNA from hybrid lines carrying fragments of the X chromosome; and (3) in situ hybridization to metaphase chromosomes. The use of dosage as a means to regionally assign probes significantly improves resolution of the X chromosome.
Mosaic variegated trisomy (42, XY/43, XY, + variable) in a male pigtail macaque monkey
Authors: Vigfusson N.V. , Dawson R.J. , Jones J.F. , Shaw K.J. , Lloyd M.A. , Ruppenthal G.C , Sackett G.P.
Published: May 2008

We identified an infant male pigtail macaque monkey with a bizarre karyotype which, to the best of our knowledge, has never before been reported in any species. Examination of 107 nuclei from cultured lymphocytes revealed 81 (75.7%) to be trisomic, but with the supernumerary chromosome varying from cell to cell, trisomy 16 being the most common. A small percentage (11.2%) of the nuclei had a normal 42, XY karyotype, and the balance, with the exception of one apparent monosomic (possibly a technical artifact), had multiple chromosome abnormalities. Examination of cultured skin fibroblasts revealed a similar karyotype. We called this karyotype a mosaic variegated trisomy. At birth, the animal had a cleft lip and palate and situs inversus of the heart. He subsequently showed significant developmental delay and apparent mental retardation. There were no clinical symptoms of hematological malignancy, which often have associated acquired chromosome abnormalities such as those described here. The animal survived for 2 yr and 8 mo under intensive care.
DAPI-inducible common fragile sites
Authors: Pelliccia F. , Rocchi A.
Published: May 2008

DAPI, a compound specific for the AT bases of DNA, causes gaps and breaks in three human chromosome sites, at the 1q41 1q42 interface, 2q31, and 7p22. It also induces undercondensation of a chromosome site at the 13q21–13q22 interface. The first three sites have the characteristics of “common fragile sites” and are present as gaps and breaks on the chromosomes of seven individuals.
Nucleolus organizer chromosomes in a teleostean species of tetraploid origin, Cyprinus carpio
Authors: Sola L. , Arcangeli R. , Cataudella S.
Published: May 2008

The presence of nucleolus organizer regions (NORs) was investigated in a teleostean species of tetraploid origin, Cyprinus carpio, by means of Ag-staining. Even if four NOR-bearing chromosomes exist, only two of them are normally active. This evidence supports the hypothesis that, in this species, diploidization of gene expression may be due to a reduction in the rate of rRNA transcription.
Mapping of the DNA locus D4S10 and the linked Huntington’s disease gene to 4p16→p15
Authors: Zabel B.U. , Naylor S.L. , Sakaguchi A.Y. , Gusella J.F.
Published: May 2008

An anonymous DNA fragment (G8) detects two restriction fragment length polymorphic alleles (RFLPs) called D4S10 in HindIII-digested human genomic DNA. This segment had been assigned to chromosome 4 and shows close linkage to the Huntington’s disease gene. With in situ hybridization, we mapped D4S10 to the terminal region of the short arm of chromosome 4, localizing the Huntington’s disease gene to bands 4p16→p15. This information may prove useful for the development of strategies to clone the Huntington’s disease gene.
Regional assignment of the erythropoietin gene to human chromosome region 7pter→q22
Authors: Watkins P.C. , Eddy R. , Hoffman N. , Stanislovitis P. , Beck A.K. , Galli J. , Vellucci V. , Gusella J.F. , Shows T.B.
Published: May 2008

The chromosomal location of the human gene for erythropoietin (EPO) was determined by Southern blot hybridization analysis of a panel of human-mouse somatic hybrid cell DNAs. DNAs from cell hybrids containing reduced numbers of human chromosomes were treated with the restriction enzyme PstIand screened with a cloned human EPO cDNA probe. EPO is assigned to human chromosome 7 based on the complete cosegregation of EPO with this chromosome in all 45 cell hybrids tested. A cell hybrid containing a translocated derivative of chromosome 7 localizes EPO to 7pter→q22. A HindIII restriction fragment length polymorphism is detected by hybridization of the EPO cDNA probe to human genomic DNA.
Assignment of RAS proto-oncogenes in Chinese hamsters: implications for mammalian gene linkage conservation and neoplasia
Authors: Stallings R.L. , Crawford B.D. , Black R.J. , Chang E.H.
Published: May 2008

HRAS and KRAS are the cellular homologs of the oncogenic transforming genes found in the Harvey strain of murine sarcoma virus and the Kirsten murine sarcoma virus, respectively. Phyla as diverse as insects, birds, and mammals possess distinct HRAS and KRAS sequences, suggesting that these genes are essential to metazoa. In this report, we used a clone panel of Chinese hamster × mouse CUD somatic cell hybrids segregating hamster chromosomes to map those genes. Southern filter hybridization analyses of the hybrids revealed that hamster HRAS and KRAS gene sequences are on chromosomes 3 and 8, respectively. These gene assignments are consistent with the conservation of autosomal gene linkage groups observed among hamsters, humans, and mice and may provide insight into specific chromosomal alterations that have been observed during the spontaneous neoplastic transformation of Chinese hamster fibroblasts in vitro.
A new location for the human adenine phosphoribosyltransferase gene (APRT) distal to the haptoglobin (HP) and fra(16)(q23) (FRA16D) loci
Authors: Fratini A. , Simmers R.N. , Callen D.F. , Hyland V.J. , Tischfield J.A. , Stambrook P.J. , Sutherland G.R.
Published: May 2008

The human adenine phosphoribosyltransferase gene (APRT) was mapped with respect to the haptoglobin gene (HP) and the fragile site at 16q23.2 (FRA16D). A subclone of APRT and a cDNA clone of HP were used for molecular hybridization to DNA from mouse-human hybrid cell lines containing specific chromosome 16 translocations. The APRT subclone was used for in situ hybridization to chromosomes expressing FRA16D. APRT was found to be distal to HP and FRA16D and was localized at 16q24, making the gene order cen-FRA16B-HP-FRA16D-APRT-qter.
Sex chromosome-autosome translocations in the leaf-nosed bats, family Phyllostomidae
Authors: Tucker P.K.
Published: May 2008

Mitotic analyses using RBA- and C-banding were performed on Stenodermatine bats with X-autosome (XY1Y2) and X- and Y- autosome (neo-XY) translocations. RBA-banded metaphases of females revealed differential replication of the inactive X chromosome. An early replicating band comprises the short arm of the X, and an intermediate replicating band is located interstitially on sthe long arm. The early replicating short arm has a homologous counterpart either in the form of a free autosome (the Y2) or as part of the Y. Both the “autosomal” short arm of the X and its homologue fused to the Y are C-band negative and behave autonomously from the remainder of the sex chromosomes. They are separated from X and Y chromatin by centromeric heterochromatin which presumably acts as a barrier. The intermediate replicating region of the long arm of the X is also present in the subfamily Phyllostominae. In both subfamilies this region lacks a homologous counterpart. However, it may also represent a translocated autosome which, unlike the short arm of the X, is not separated from the inactive X by centromeric heterochromatin. Its intermediate replication time may represent a retarded replication due to its juxtaposition to late replicating X chromatin. These data are discussed in light of the theory of the evolution of sex chromosome heteromorphism, specifically as it applies to mammals.
Premature centromere division dominantly inherited in a subfertile family
Authors: Gabarrón J. , Jimenez A. , Glover G.
Published: May 2008

An increased frequency of mitoses showing premature centromere division (PCD) in every chromosome was found in lymphocyte cultures from four members of a subfertile family. These cells were observed in both the presence and absence of colchicine. Cultured fibroblasts from the proband showed only normal diploid metaphases. PCD cells seemed to have a shorter cell cycle. The anomaly was transmitted in a way compatible with autosomal dominant inheritance in this family.
Molecular characterization of the purity of seven human chromosome-specific DNA libraries
Authors: Perlman J. , Fuscoe J.C.
Published: May 2008

We have characterized at the molecular level seven chromosome-specific libraries constructed in phage λ Charon 21A from flow-sorted human chromosomes. The purity of libraries prepared from chromosomes sorted from hamster × human cells was estimated by species-specific hybridization and ranged from 48% to 83% of clones containing human inserts. Among libraries of chromosomes from human cells, mass screenings were made for repetitive sequences and 20 clones from the # 18 and # 20 libraries were analyzed in detail. Ten to fifteen percent of all clones contain sequences which can be mapped; 80 100% of these derive from the intended chromosome of origin, demonstrating very high purity and a 35 × enrichment of chromosome-specific sequences over a total genomic library. The two libraries contain a high, though dissimilar, percent of repeat-containing clones; the # 18 library has 55% repetitive clones and the # 20 library 85%. This dissimilarity may be due to a difference in insert size distribution, since the # 18 library has smaller inserts than the # 20. This could be caused by variation in extent of digestion of insert DNA and/or differences in sequence organization between the two chromosomes. A method more sensitive than conventional plaque-lift screening was used to detect repetitive inserts; in this way nearly all repetitive clones could be eliminated before purification of their DNAs.
Occurrence of premature chromosome condensation in mouse spermatogonia treated with busulfan
Authors: Yamamoto K.I. , Hitotsumachi S. , Kikuchi Y.
Published: May 2008

Busulfan induction of premature chromosome condensation (PCC) was examined in mouse spermatogonia. Adult (C3H × SWV) Ft male mice were injected intraperitoneally with busulfan at 10 or 30 mg/kg of body weight and killed 18–72 h later. Polyploid-like mitoses were frequent (ca. ¼ of all sper-matogonial mitoses examined) in both the untreated and treated groups. Most of these were considered to have been derived from normal spermatogonia. In busulfan-treated mice, polyploid-like mitoses with PCC were seen. The frequency of PCC-containing mitoses increased with increasing dose and exposure time. A possible interpretation for PCC induction in mouse spermatogonia is discussed.
Owl monkey gene loci for c-fes and albumin are syntenic
Authors: Ma N.S.F.
Published: May 2008

Segregation analysis of rodent-owl monkey somatic cell hybrids probed with a human c-fes DNA sequence disclosed the owl monkey c-fes locus to be syntenic with the albumin loci on chromosome 1 of karyotype VI, chromosome 12 of karyotype V, and chromosome 9 of karyotype IV. This finding substantiates the proposed homology of these chromosomes and demonstrates the complexity of rearrangement of individual genes during chromosomal phylogeny which is not detectable by morphological comparison alone.
Aneuploidy is not induced by ethanol during spermatogenesis in the Chinese hamster
Authors: Daniel A. , Roane D.
Published: May 2008

Aneuploidy was scored in spermatogonial stages and at both meiotic divisions in male Chinese hamsters exposed to alcohol in vivo. After light ether anesthetization, the animals were intubated (by gastric tube) with 1.5 ml of 12.5% ethanol, whereas controls were given 1.5 ml of distilled water. Gonadectomy was performed 3.5–24 h after ethanol exposure. Ethanol-dosed animals were obviously intoxicated, as evidenced by a rolling gait; serum alcohol levels in 10 animals that were tested peaked 1–2 h after exposure. Among the animals exposed to ethanol, no significant difference over time in the rates of aneuploidy was observed. These data were pooled, and, when compared to control rates, no significant difference could be attributed to ethanol exposure. The aneuploidy found could therefore be interpreted as background rates, and these compared well with data previously published for the Chinese hamster. Several artifactual phenomena were observed: Up to 15% aneuploid spermatogonial metaphases were seen in test and control animals. These were attributed to the mechanical breaking-up of closely apposed groups of diploid spermatogonia. Significant numbers of artifactual diploid MII figures and hypohaploid MI and MII figures were also recorded. To address the possibility that a spermatogonial or other long-term effect could be detected, two animals (with controls) were dosed with 12.5% ethanol daily for 13 and 16 days before sacrifice. No aneuploidy attributable to ethanol was found at MII in these animals either.
The AluI-induced bands in great apes and man: implication for heterochromatin characterization and satellite DNA distribution
Authors: Ferrucci L. , Romano E. , de Stefano G.F.
Published: May 2008

Restriction endonucleases have recently been proved to be active on fixed chromatin, producing differences in staining of metaphase chromosomes. In this paper we show the results obtained by treating the metaphase chromosomes of Pan troglodytes, Pan paniscus, and Gorilla gorilla with the restriction enzyme AM. These results demonstrate qualitative differences in the telomeric heterochromatin between Pan and Gorilla despite the fact that these areas appear homogeneous in the two genera by the C-banding method. The results found with individual chromosomes in the different species also appear relevant, in the light of the evolutionary relationships between these nonhuman primates and man. Lastly, the results suggest the presence, in great apes, of some highly repetitive DNA sequences different from the human satellites I IV.
Integration sites of human papillomavirus 18 DNA sequences on HeLa cell chromosomes
Authors: Popescu N.C. , DiPaolo J.A. , Amsbaugh S.C.
Published: May 2008

Human papillomaviruses (HPV) 16 and 18 are closely linked with human genital cancer. In most cervical carcinomas, viral sequences are integrated into the host genome. HeLa, a cervical carcinoma cell line, has multiple copies of integrated HPV 18 DNA. In this study, in situ chromosome hybridization was used to assign the integration sites of HPV 18 DNA sequences on HeLa cell chromosomes. Four sites of hybridization were identified at 8q23→q24, 9q31→q34, p11→p13 on an abnormal chromosome 5, and q12→q13 on an abnormal 22. Three of these sites correspond with the locations of MYC, ABL, and SIS protooncogenes, and are at or in close proximity to fragile sites. The chromosomal localization of HPV 18 DNA may be useful in assessing the role of viral integration in the development of this malignancy.
Gene assignments and syntenic groups in the sacred baboon (Papio hamadryas)
Authors: Thiessen K.M. , Lalley P.A.
Published: May 2008

Eighteen genes were assigned to chromosomes in the sacred baboon, Papio hamadryas, by their concordant segregation with the chromosomes in a set of baboon × Chinese hamster somatic cell hybrids. ACY1 was assigned to P. hamadryas chromosome 2 (PHA 2); SOD1 and MDH2 to PHA 3; ME1 and SOD2 to PHA 4; NP, MPI, PKM2, and HEXA to PHA 7; PP to PHA 9; ADA and ITPA to PHA 10; LDHB and TPI1 to PHA 11; MDH1 to PHA 13; ESD to PHA 17; and GPI and PEPD to PHA 20. Regional assignments were possible for ACY1 (PHA 2pter→q1) and MDH2 and SOD1 (PHA 3p). Five other independently segregating markers or syntenic groups (PGD, PGM 1; and PEPC; PGM2 and PEPS; IDH1; LDHA and ACP2; and GSR) were also identified. Gene assignments and syntenic groups described in P. hamadryas are compared to those found in P. papio, the rhesus monkey, and man. A possible primate model for human lymphoid disease is discussed.
Mapping polypeptide hormone genes in the mouse: somatostatin, glucagon, calcitonin, and parathyroid hormone
Authors: Lalley P.A. , Sakaguchi A.Y. , Eddy R.L. , Honey N.H. , Bell G.I. , Shen L.-P. , Rutter W.J. , Jacobs J.W. , Heinrich G. , Chin W.W. , Naylor S.L.
Published: May 2008

Mouse-Chinese hamster hybrids segregating mouse chromosomes were analyzed by Southern hybridization techniques to map the genes for somatostatin (Smst), glucagon (Gcg), calcitonin (Calc) and parathyroid hormone (Pth). The mouse gene for somatostatin, detected on a 20-kb EcoRl fragment, is located on mouse chromosome 16. Glucagon cDNA hybridized to a 14-kb EcoRl fragment residing on chromosome 2. Calcitonin and parathyroid hormone genes, detected on 7.8-kb HindIII and 6.0-kb BamHI fragments, respectively, were on mouse chromosome 7. The calcitonin and parathyroid hormone genes appear to be part of a larger linkage group which has been conserved in mouse and man.
Localization of the human catalase and apolipoprotein A-I genes to chromosome 11
Authors: Schroeder W.T. , Saunders G.F.
Published: May 2008

Studies of the catalase and apolipoprotein A-I genes are pertinent to the understanding of human disease. Not only are these genes involved in acatalasemia and atherosclerosis, respectively, but they are also important gene markers for chromosome 11, deletions of which are involved in the development of Wilms tumor. We have used in situ hybridization to localize these genes to specific bands on chromosome 11. Hybridization with a catalase cDNA yielded a significant number of cells (38%) exhibiting label at band 1 lpl3. A high percentage of metaphase cells (50%) hybridized with a human genomic fragment containing the gene for apolipoprotein A-I displayed labeling at 11q13.
Conservation of human-derived pseudoautosomal sequences on the sex chromosomes of the great apes
Authors: Weber B. , Weissenbach J. , Schempp W.
Published: May 2008

In situ hybridization using a repeated element specific for the human pseudoautosomal region, DXYZ2, revealed the presence of this repeat in the early replicating portion of the sex chromosomes of the great apes. This segment, as well as the DXYZ2 repeats, are located in band Xp22.3 and in a telomeric or subtelomeric region of the Y chromosome. These segments may therefore represent pseudoautosomal regions, as in man.
The human neurofilament gene (NEFL) is located on the short arm of chromosome 8
Authors: Hurst J. , Flavell D. , Julien J.-P. , Meijer D. , Mushynski W. , Grosveld F.
Published: May 2008

We have localized the gene coding for the human neurofilament light chain (NEFL) to chromosome band 8p2.1 by Southern blotting of DNA from hybrid cell panels and in situ hybridization to metaphase chromosomes.
Synaptonemal complex analysis of the B-chromosomes in spermatocytes of the silver fox (Vulpes fulvus Desm.)
Authors: Świtoński M. , Gustavsson I. , Höjer K. , Plöen L.
Published: May 2008

The mitotic and meiotic chromosomes of four male silver foxes (Vulpes fulvus Desm.) having, due to inter- and intraindividual variation, 1–4 B-chromosomes in addition to the standard karyotype, were investigated with special attention given to pachytene chromosome behaviour as revealed by electron and light microscopy. When occurring as univalents the B-chromosomes demonstrated a progressively folding back behavior ending in intrachromosomal pairing. When two B-chromosomes occurred in the same cell they paired normally as a bivalent with one central and two lateral elements. However, occasionally also two univalents were seen. In the presence of three B-chromosomes, a trivalent occurred in most cells, but sometimes two normally paired chromosomes and one folded univalent were seen in late pachytene. The chromosomes comprising the trivalent were never completely paired, however. Due to competitive pairing and low frequency of chiasmata the trivalents most often dissolved into one bivalent and one univalent and only a few trivalents remained at diakinesis-metaphase I. On the basis of pairing behavior and morphology it is assumed that the B-chromosomes of the silver fox are homologous. Although pairing was never observed, there was a tendency of association at pachytene between B-chromosome configurations and the sex bivalent in those individuals that had univalents and trivalents.
Patterns of chromosome breakage in nonHodgkin lymphoma: significance to gene alteration in tumorigenesis
Authors: Chaganti R.S.K. , Koduru P.R.K.
Published: May 2008

In a comprehensive cytogenetic analysis of nonHodgkin lymphoma (NHL) that was based on a database derived from karyotypic descriptions of 264 tumors, we previously established correlations between specific chromosome changes and histologic subtypes of lymphoma. In the present paper we analyze the total chromosome breakage encountered in this group of tumors. This analysis permitted distinction between sites of nonrandom breakage that are specific for lymphoid tumors (and hence of probable primary or etiologic significance) and sites of nonrandom breakage that are common to lymphoid as well as nonlymphoid tumors (and hence of probable secondary or evolutionary significance). We also observed that breakage affected all of the immunoglobulin and T cell receptor gene sites and most of the known cellular oncogene and fragile sites; however, only a limited number of these sites exhibited statistically significant breakage. Of special interest was the fact that the fragile sites that exhibited significant breakage were mostly those that also were sites of cellular oncogenes. Our data suggest that breakage at sites of immunoglobulin genes and a limited number of cellular oncogenes alone is of importance in B-cell lymphomagenesis. While the timing or causes of genomic destabilization in tumorigenesis are unknown, recent molecular analysis of junction regions of chromosome rearrangements designated here as primary translocations has suggested that more than one mechanism may be involved in their generation. This study identifies chromosomal sites of nonrandom perturbation that may be targeted for detailed molecular analysis aimed at understanding the origin, evolution, and spread of B-cell NHL.
A cytogenetic, phenotypic, and molecular study of an immunoblastic lymphoma with a 14q+ translocation
Authors: Sozzi G. , Agresti A. , Bertoglio M.G. , Borrello M.G. , Delia D. , Giardini R. , Pierotti M.A. , Rilke F. , Della Porta G.
Published: May 2008

An uncultured immunoblastic lymphoma, obtained from an untreated patient, was examined from a cytogenetic, immunophenotypic, and molecular viewpoint. The B-cell lineage, immunoglobulin light-chain type, and percentage of neoplastic cells were determined immunologically. Karyotyping showed the presence of a 14q+ marker and suggested that the donor chromosome was chromosome 8. Southern-blot analysis of DNA from normal and lymphoma cells, using as molecular probes sequences related to the IGHJ and IGK immunoglobulin genes, confirmed the immunophenotype. A similar analysis, using probes homologous to IGHAC and MYC genes, showed that the t(8;14) detected by cytogenetic analysis resulted in a IGHAC-MYC rearrangement.
Regional chromosomal assignment of human renin gene to 1q12→qter and use in linkage studies in Charcot-Marie-Tooth disease
Authors: Griffiths L.R. , Nicholson G.A. , Ross D.A. , Zwi M.B. , McLeod J.G. , Mohandas T. , Morris B.J.
Published: May 2008

The gene for renin, previously mapped to human chromosome 1, was further localized to 1q12→qter using human-mouse somatic cell hybrid DNAs. The renin DNA probe used (λHR5) could detect a HindIII restriction fragment length polymorphism. When used in studies of 12 informative families, no linkage could be found between the renin gene and Charcot-Marie-Tooth disease. Furthermore, an association of any renin allele with hypertension was not apparent.
Nox4 and Nox2 NADPH Oxidases Mediate Distinct Cellular Redox Signaling Responses to Agonist Stimulation
Authors: Anilkumar Narayana , Weber Roberta , Zhang Min , Brewer Alison , Shah Ajay M.
Published: May 2008

Objectives—

The NADPH oxidase isoforms Nox2 and Nox4 are coexpressed in many cell types and are implicated in agonist-stimulated redox-sensitive signal transduction. We compared the involvement of Nox2 versus Nox4 in redox-sensitive protein kinase activation after agonist stimulation.

Methods and Results—

We transfected HEK293 cells with Nox2 or Nox4 and compared ROS production and activation of mitogen activated protein kinases (MAPKs), Akt, and GSK3β after acute agonist stimulation. Nox4 overexpression substantially increased basal ROS generation whereas ROS generation in response to angiotensin II and tumor necrosis factor (TNF)α was enhanced in Nox2-overexpressing cells. Nox4 overexpression induced basal activation of ERK1/2 and JNK whereas Nox2-transfected cells showed a modest increase in p38MAPK activation. After angiotensin II or TNFα treatment, JNK activation was augmented in Nox2 but not Nox4-transfected cells, whereas insulin augmented phosphorylation of p38MAPK, Akt, and GSK3β specifically in Nox4-overexpressing cells and JNK specifically in Nox2-overexpressing cells.

Conclusions—

These data indicate that Nox2 and Nox4 exhibit distinctive patterns of acute activation by angiotensin II, TNFα, and insulin and regulate the activation of distinct protein kinases.
Prognostic Value of Leukocyte Telomere Length in Patients With Stable Coronary Artery Disease
Authors: Farzaneh-Far Ramin , Cawthon Richard M. , Na Beeya , Browner Warren S. , Schiller Nelson B. , Whooley Mary A.
Published: May 2008

Background—

Telomere shortening has been proposed as a marker of biological aging. Whether leukocyte telomere length is associated with mortality among patients with stable coronary artery disease (CAD) is unknown.

Methods and Results—

We measured leukocyte telomere length in 780 patients with stable CAD in a prospective cohort study. Participants were categorized by quartiles of telomere length. Hazard Ratios (HRs) and 95% confidence intervals were calculated for all-cause mortality, heart failure (HF) hospitalization, and cardiovascular (CV) events. After 4.4 years of follow-up there were 166 deaths. Compared with participants in the highest telomere length quartile, those in the lowest quartile were at increased risk of death (age-adjusted HR 1.8; 95% CI 1.2 to 2.9). After multivariate adjustment for clinical (HR 2.1; CI 1.3 to 3.3), inflammatory (HR 2.0; CI 1.2 to 3.2), and echocardiographic (HR 1.9; CI 1.0 to 3.5) risk factors, patients in the lowest quartile of telomere length remained at significantly increased risk of death compared to those in the highest quartile. Patients in the lowest quartile of telomere length were also at significantly increased risk of HF hospitalization (HR 2.6; CI 1.1 to 6.0) but not CV events (HR 1.7; CI 0.9 to 3.5).

Conclusions—

Reduced leukocyte telomere length is associated with all-cause mortality in patients with stable CAD. The prognostic value of short telomeres in predicting death is not completely captured by existing clinical, inflammatory, and echocardiographic markers of risk.
Interaction of α1-Adrenoceptor Subtypes With Different G Proteins Induces Opposite Effects on Cardiac L-type Ca2+Channel
Authors: O-Uchi Jin , Sasaki Hiroyuki , Morimoto Satoshi , Kusakari Yoichiro , Shinji Hitomi , Obata Toru , Hongo Kenichi , Komukai Kimiaki , Kurihara Satoshi
Published: May 2008

We examined the effect of α1-adrenoceptor subtype-specific stimulation on L-type Ca2+current (ICa) and elucidated the subtype-specific intracellular mechanisms for the regulation of L-type Ca2+channels in isolated rat ventricular myocytes. We confirmed the protein expression of α1A- and α1B-adrenoceptor subtypes at the transverse tubules (T-tubules) and found that simultaneous stimulation of these 2 receptor subtypes by nonsubtype selective agonist, phenylephrine, showed 2 opposite effects onICa(transient decrease followed by sustained increase). However, selective α1A-adrenoceptor stimulation (≥0.1 μmol/L A61603) only potentiatedICa, and selective α1B-adrenoceptor stimulation (10 μmol/L phenylephrine with 2 μ mol/L WB4101) only decreasedICa. The positive effect by α1A-adrenoceptor stimulation was blocked by the inhibition of phospholipase C (PLC), protein kinase C (PKC), or Ca2+/calmodulin-dependent protein kinase II (CaMKII). The negative effect by α1B-adrenoceptor stimulation disappeared after the treatment of pertussis toxin or by the prepulse depolarization, but was not attriburable to the inhibition of cAMP-dependent pathway. The translocation of PKCδ and ε to the T-tubules was observed only after α1A-adrenoceptor stimulation, but not after α1B-adrenoceptor stimulation. Immunoprecipitaion analysis revealed that α1A-adrenoceptor was associated with Gq/11, but α1B-adrenoceptor interacted with one of the pertussis toxin-sensitive G proteins, Go. These findings demonstrated that the interactions of α1-adrenoceptor subtypes with different G proteins elicit the formation of separate signaling cascades, which produce the opposite effects onICa. The coupling of α1A-adrenoceptor with Gq/11-PLC-PKC-CaMKII pathway potentiatesICa. In contrast, α1B-adrenoceptor interacts with Go, of which the βγ-complex might directly inhibit the channel activity at T-tubules.
Hypoxia-Inducible Transcription Factor-1α Triggers an Autocrine Survival Pathway During Embryonic Cardiac Outflow Tract Remodeling
Authors: Liu Hongbin , Fisher Steven A.
Published: May 2008

The cardiac outflow tract (OFT) of birds and mammals undergoes complex remodeling in the transition to a dual circulation. We have previously suggested a role of myocardial hypoxia and hypoxia inducible factor (HIF)-1 in the apoptosis-dependent remodeling of the OFT. In the present study, we transduced recombinant adenovirus-mediated HIF-1α in embryonic chick OFT myocardium to test its role in OFT remodeling. HIF-1α reduced the prevalence of apoptosis in OFT cardiomyocytes at stages 25 and 30, as determined by lysosome accumulation and caspase-3 activity. Associated conotruncal defects included malrotation of the aorta and excessive infundibular myocardium. HIF-1 targets induced in these gain-of-function experiments included vascular endothelial growth factor (VEGF), inducible nitric oxide synthase, and stromal cell–derived factor-1. To test the role of VEGF in this context, an adenovirus expressing secreted Flk1 (VEGF receptor 2) that binds and blocks VEGF signaling was targeted to the OFT myocardium. This caused increased cell death in the OFT myocardium at stages 25 and 30. Associated conotruncal heart defects included malrotation of the aorta, defects in the subpulmonic infundibulum associated with a small right ventricle, and increased OFT mesenchyme with failure of semilunar valve formation. We conclude that hypoxia signaling through HIF-1 and VEGF provides an autocrine survival signal in the developing cardiac OFT and that perturbation in this pathway causes OFT defects that model congenital human conotruncal heart defects.
Functional Mineralocorticoid Receptors in Human Vascular Endothelial Cells Regulate Intercellular Adhesion Molecule-1 Expression and Promote Leukocyte Adhesion
Authors: Caprio Massimiliano , Newfell Brenna G. , la Sala Andrea , Baur Wendy , Fabbri Andrea , Rosano Giuseppe , Mendelsohn Michael E. , Jaffe Iris Z.
Published: May 2008

In clinical trials, aldosterone antagonists decrease cardiovascular mortality and ischemia by unknown mechanisms. The steroid hormone aldosterone acts by binding to the mineralocorticoid receptor (MR), a ligand-activated transcription factor. In humans, aldosterone causes MR-dependent endothelial cell (EC) dysfunction and in animal models, aldosterone increases vascular macrophage infiltration and atherosclerosis. MR antagonists inhibit these effects without changing blood pressure, suggesting a direct role for vascular MR in EC function and atherosclerosis. Whether human vascular ECs express functional MR is not known. Here, we show that human coronary artery and aortic ECs express MR mRNA and protein and that EC MR mediates aldosterone-dependent gene transcription. Human ECs also express the enzyme 11-β-hydroxysteroid dehydrogenase-2 (11βHSD2), and inhibition of 11βHSD2 in aortic ECs enhances gene transactivation by cortisol, supporting that EC 11βHSD2 is functional. Furthermore, aldosterone stimulates transcription of the proatherogenic leukocyte–EC adhesion molecule intercellular adhesion molecule (ICAM)1 gene and protein expression on human coronary artery ECs, an effect inhibited by the MR antagonist spironolactone and by MR knock down with small interfering RNA. Cell adhesion assays demonstrate that aldosterone promotes leukocyte–EC adhesion, an effect that is inhibited by spironolactone and ICAM1 blocking antibody, supporting that aldosterone induction of EC ICAM1 surface expression via MR mediates leukocyte–EC adhesion. These data show that aldosterone activates endogenous EC MR and proatherogenic gene expression in clinically important human ECs. These studies describe a novel mechanism by which aldosterone may influence ischemic cardiovascular events and support a new explanation for the decrease in ischemic events in patients treated with aldosterone antagonists.