bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloning and characterization of a novel gene (C8orf2), a human representative of a novel gene family with homology to C. elegans C42.C1.9
Authors: Ikegawa S. , Isomura M. , Koshizuka Y. , Nakamura Y.
Published: April 2003

Large-scale sequencing of selected genomic regions, coupled with in silico gene trapping, is a robust approach to identifying previously unknown genes. In this way we have found a gene (C8orf2) that is highly homologous to C. elegans C42C1.9. C8orf2 was situated on 8p11.2 between STS markers NIB1979 (proximal) and AFMA295ZD5 (distal), oriented toward the centromere. C8orf2 consisted of 16 exons spanning more than 16.5 kb of genomic DNA, and was expressed ubiquitously in human tissues. The gene encoded 339-and 152-amino acid polypeptides by alternative splicing; the larger variant contained a region extremely rich in charged amino acids, in particular lysine and glutamic acid. C8orf2 also bore sequence homology to the human KE04p gene. Its conservation among highly divergent species suggests that C8orf2 belongs to a novel gene family.
Genomic structure and chromosome location of RPL27A/Rpl27a, the genes encoding human and mouse ribosomal protein L27A
Authors: Kusuda, J. , Hirai M. , Tanuma R. , Hirata M. , Hashimoto K.
Published: April 2003

The intron-containing genes encoding human and mouse ribosomal protein (r-protein) L27A were cloned and sequenced. The human r-protein L27A gene (RPL27A) shared an identical exon/intron structure with the mouse r-protein 27A gene (Rpl27a). The translational start codon ATG was separated from the main reading frame by the first intron sequence in both genes. An approximately 200-bp sequence upstream of the translational start site of both genes displayed remarkable similarity, and contained the putative promoters lacking canonical TATA, but harbored Sp1 binding sites and a short stretch of pyrimidine cluster, similar to other r-protein genes. Transcriptional regulatory elements, Box-A and GABP, found in the promoters of some other r-protein genes were also conserved in both genes. These structural features were included in the typical CpG island identified in the 5′-end sequences, suggesting that RPL27A/Rpl27a cloned here are authentic and transcriptionally active. Fluorescence in situ hybridization (FISH) analysis localized the mouse intron-containing Rpl27a to chromosome 7E2–F1 syntenic to human chromosome 11p15, where human RPL27A was located.
Comparative mapping between human chromosome 3 and porcine chromosome 13
Authors: van Poucke M. , Törnsten A. , Mattheeuws M. , van Zeveren A. , Peelman L.J. , Chowdhary B.P.
Published: April 2003

Zoo-FISH and somatic cell hybrid panels have earlier demonstrated extended synteny conservation between human chromosome 3 (HSA3) and pig chromosome 13 (SSC13). In the present study, eight human genes viz., ADCY5, CASR, COL7A1, COL8A1, ITIH1, RHO, SIAT1 and XPC, spread along the length of HSA3, were chosen for expanding the comparative map between the two chromosomes. Using human and rat cDNAs, or human- and porcine-specific PCR products as probes, 8 porcine lambda clones were isolated. After subcloning and partial sequence determination, identity of the clones with regards to the specific genes was established. The eight type 1 markers thus obtained were biotin labeled and FISH mapped to pig metaphase spreads. All lambda clones localized to SSC13. In combination with the hitherto published mapping data of coding sequences on SSC13, a preliminary comparative status depicting the relative organization of this chromosome with respect to HSA3 was developed. The comparative map thus obtained bears significance in searching for candidate genes of economically important traits mapped to SSC13.
Cloning, characterization, and chromosome assignment of Zfp146 the mouse ortholog of human ZNF146, a gene amplified and overexpressed in pancreatic cancer, and Zfp260  a closely related gene
Authors: Blottière L. , Apiou F. , Ferbus D. , Guenzi C. , Dutrillaux B. , Prospéri M.-T. , Goubin G.
Published: April 2003

The human OZF gene (ZNF146), located in chromosome band 19q13.1, is amplified and overexpressed in pancreatic carcinomas. It encodes a protein consisting solely of ten Krüppel zinc finger motifs. We report here the isolation and the characterization of the murine OZF cDNA (Zfp146). Comparison of the deduced amino acid sequences between murine, human and bovine cDNAs revealed a strong identity (95%). A closely related gene, Zfp260, was also isolated and characterized. It encodes a putative protein consisting of three vestigial zinc finger motifs followed by ten Krüppel zinc fingers sharing 79% identity and no gap insertion with the Zfp146 zinc fingers. In vitro transcription/translation of both genes led to synthesis of proteins of the predicted size. Co-expression was observed at the mRNA level in eight adult mouse tissues. Two-color FISH revealed co-localization of both genes on mouse chromosome 7 (band B1–B3). The co-expression and co-localization of Zfp146 and Zfp260 together with the close similarity of their zinc finger domains, suggests that both participate in the same regulatory pathway.
The influence of interstitial telomeric sequences on chromosome instability in human cells
Authors: Desmaze C. , Alberti C. , Martins L. , Pottier G. , Sprung C.N. , Murnane J.P. , Sabatier L.
Published: April 2003

Although most telomere repeat sequences are found at the ends of chromosomes, some telomeric repeat sequences are also found at intrachromosomal locations in mammalian cells. Several studies have found that these interstitial telomeric repeat sequences can promote chromosome instability in rodent cells, either spontaneously or following ionizing radiation. In the present study we describe the extensive cytogenetic analysis of three different human cell lines with plasmids containing telomeric repeat sequences integrated at interstitial sites. In two of these cell lines, Q18 and P8SX, instability has been detected in the chromosome containing the integrated plasmid, involving breakage/fusion/bridge cycles or amplification of the plasmid DNA, respectively. However, the data suggest that the instability observed is characteristic of the general instability in these cell lines and that the telomeric repeat sequences themselves are not responsible. Consistent with this interpretation, the chromosome containing an integrated plasmid with 500 bp of telomeric repeat sequences is highly stable in the third cell line, SNG28, which has a relatively stable genome. The stability of the chromosome containing the integrated plasmid sequences in SNG28 makes this an excellent cell line to study the effect of ionizing radiation on the stability of interstitial telomeric sequences in human cells.
Towards identification of individual homologous chromosomes: comparative genomic hybridization and spectral karyotyping discriminate between paternal and maternal euchromatin in Mus musculus × M. spretus interspecific hybrids
Authors: Hardt T. , Himmelbauer H. , Mann W. , Ropers H.-H. , Haaf T.
Published: April 2003

We have developed an in situ technique to label individual euchromatic chromosome arms in interspecific crosses between Mus musculus (MMU) and M. spretus (MSP). The MMU and MSP genomes diverged 2–3 million years ago and show an overall sequence divergence of approximately 1%. Comparative hybridization of MMU versus MSP DNA and subsequent spectral analysis of the euchromatic hybridization profiles discriminated between maternal (MMU) and paternal (MSP) chromosomes in F1 hybrids. Dispersed repetitive DNA elements were the preferred hybridization target of MMU DNA on maternal chromosomes and of MSP DNA on paternal chromosomes. Differences in centromeric satellite DNAs were detected by conventional fluorescence in situ hybridization and served as internal controls. Our experiments suggest that it is possible, in principle, to discriminate between paternal and maternal chromosomes on the basis of sequence differences.
Telomeric repeat organization—a comparative in situ study between man and rodent
Authors: Serakıncı N. , Krejčí K. , Koch J.
Published: April 2003

Human, hamster, and mouse chromosomes show both similarities and differences in telomeric organization, detectable with a novel version of the PRINS technique. The differences allowed us to investigate the fate of the telomeres on a chromosome from one species when this chromosome was introduced into the cells of another species. For this purpose, we tested telomeres in cell lines of somatic cell hybrids containing human chromosomes on a rodent background, finding that the telomeres on human chromosomes could not be discriminated from the telomeres on rodent chromosomes. All telomeres in the cell lines were much shorter than the telomeres in normal cells. In the mouse-derived cell lines, half of the mouse chromosomes were fused to other mouse chromosomes at the ends of their short arms. At the points of fusion we were generally unable to detect telomeric signals. In these cell lines, we also found a fraction of chromosomes ends with only one telomeric signal. In chromosomes where both ends showed only one signal, the relative orientation of the signals appeared to be nonrandom with respect to sister chromatids.
High resolution physical mapping of human HDAC3, a potential tumor suppressor gene in the 5q31 region
Authors: Mahlknecht U. , Bucala R. , Hoelzer D. , Verdin E.
Published: April 2003

Histone deacetylases have been described as crucial cofactors of mammalian transcriptional complexes. We have recently identified human histone deacetylase HDAC3 on chromosome 5q31 by fluorescence in situ hybridization (FISH) in a region commonly deleted in malignant myeloid disease. Since HDAC3 carries strong potential to be a tumor suppressor gene, we report herein its exact position between the CD14 and GRIA1 genes within the 5q31.1 subband.
Equal induction and persistence of chromosome aberrations involving chromosomes with heterogeneous lengths and gene densities
Authors: Puerto S. , Surrallés J. , Ramírez M.J. , Creus A. , Marcos R.
Published: April 2003

Little is known about the factors modulating the initial induction and persistence of chromosome aberrations. Chromosome length and gene density have been proposed to play a significant role. We have therefore analyzed the induction and persistence of γ-ray-induced aberrations involving four human chromosomes (1, 4, 18, and 19) with highly heterogeneous lengths and gene densities. Multicolor FISH was performed on a wild-type lymphoblastoid cell line 1, 3, 7, 14, 28, 42, and 56 d after γ-irradiation. The frequency of induced chromosomal aberrations was proportional to the length of the chromosomes. Complex aberrations, dicentrics, and fragments were highly unstable and disappeared during the first week after treatment and with similar kinetics for all four chromosomes. The frequency of translocations decreased with time and followed an exponential decline. Thirty percent of the γ-ray-induced translocations were stable over the entire study period, irrespective of the length and the gene density of the chromosome involved. Accordingly, we concluded that the induction of chromosome aberrations is proportional to the length of the chromosome, that gene density makes no measurable contribution to induction, and that neither length nor gene density influences the persistence of chromosome aberrations.
Identification, characterization, and mapping of a mouse homolog of the gene mutated in Nijmegen breakage syndrome
Authors: Vissinga C.S. , Yeo T.C. , Woessner J. , Massa H.F. , Wilson R.K. , Trask B.J. , Concannon P.
Published: April 2003

The rare autosomal recessive disorder Nijmegen breakage syndrome (NBS) results from mutations in the NBS1 gene on human chromosome 8q21. A mouse homolog of the NBS1 gene was isolated and its nucleotide sequence determined. Somatic cell hybrid analysis and fluorescence in situ hybridization were used to map this gene, Nbn, to mouse chromosome band 4A. Northern blotting revealed comparable levels of Nbn transcripts in most tissues in the mouse. However, transcripts were elevated 10–20 fold in the testes, consistent with a possible role for the product of the Nbn gene in meiotic recombination.
Gene structure and chromosome mapping of the human small-conductance calcium-activated potassium channel SK1 gene (KCNN1)
Authors: Litt M. , LaMorticella D. , Bond C.T. , Adelman J.P.
Published: April 2003

Small-conductance, calcium-activated potassium channels contribute to the afterhyperpolarization in central neurons and other cell types. Because these channels regulate neuronal excitability, defects in their genes could cause excitability disorders. The human cDNA encoding one such channel, SK1 (KCNN1), was recently cloned. Here we describe the gene structure of KCNN1 and its localization by radiation hybrid mapping to chromosome 19p13.1.
Identification and chromosomal localization of murine ORC3, a new member of the mouse origin recognition complex
Authors: Springer J. , Nanda I. , Hoehn K. , Schmid M. , Grummt F.
Published: April 2003

A new member of the murine origin recognition complex (ORC) related to Saccharomyces cerevisiae ORC3 has been cloned. Transcription of ORC3 is not suppressed in mouse NIH3T3 fibroblasts made quiescent by serum starvation. The transcription level of the ORC3 gene is constantly high in all phases of the cell cycle. Murine ORC3 protein contains a putative nuclear localization signal and a non-basic helix-loop-helix motif. Both motifs are conserved in eukaryotes. A potential dimerization partner of ORC3p in the murine ORC complex is ORC1p which also contains an HLH motif. This HLH motif is also highly conserved in all eukaryotic ORC1 proteins. Comparison of murine ORC3p with other ORC3-related proteins shows high amino acid homology and motif conservation leading to the conclusion that ORC3p is part of the initiation machinery conserved in eukaryotes. The mouse ORC3 gene Orc3 was assigned to mouse chromosome 4A3 by fluorescence in situ hybridization (FISH) analysis.
The SRY gene HMG-box in micro- and megabats
Authors: Bullejos M. , Sánchez A. , Burgos M. , Jiménez R. , Díaz de la Guardia R.
Published: April 2003

Sex determination in mammals is controlled by the Y-linked SRY gene, which encodes a transcription factor with a DNA-binding motif of the HMG type. The only conserved region in this gene is the HMG-box, whose nucleotide sequence is currently available in a number of mammalian taxa. However, nothing is known about this gene in bats. Here, we report partial sequences of the SRY HMG-box from four microbat and four megabat species. We used the SRY HMG- box sequences from micro- and megabats to test the phylogenetic relationships between microbats, megabats, and primates. In maximum parsimony and maximum-likelihood trees, mega- and microbat branches start in the same internal node, which is consistent with a monophyletic origin of this mammalian group.
Cloning and characterization of human FTCD on 21q22.3, a candidate gene for glutamate formiminotransferase deficiency
Authors: Solans A. , Estivill X. , de la Luna S.
Published: April 2003

We have identified a new human gene, FTCD, which maps to chromosome 21q22.3 and encodes the enzyme formiminotransferase cyclodeaminase, an intermediate metabolism enzyme that links histidine catabolism to folate metabolism. The major cDNA encodes a protein containing 541 amino acid residues and shows 84% identity with porcine FTCD. Several other cDNAs have been isolated, which may result from alternative splicing events and have the potential to code for three different protein isoforms. The gene is highly expressed in human fetal and adult liver. The two FTCD protein domains show high sequence similarity to two distinct open reading frames from eubacterial genomes, suggesting that eukaryotic FTCD appeared through a gene fusion event. Defects in the glutamate formiminotransferase pathway have been documented, and the deficiency is presumed to be inherited as an autosomal recessive trait. The sequence reported here may be helpful in identifying the primary defect in glutamate formiminotransferase deficiency and establishing a molecular diagnosis.
RET rearrangements in papillary thyroid carcinomas and adenomas detected by interphase FISH
Authors: Cinti R. , Yin L. , Ilc K. , Berger N. , Basolo F. , Cuccato S. , Giannini R. , Torre G. , Miccoli P. , Amati P. , Romeo G. , Corvi R.
Published: April 2003

Activation of the RET protooncogene through somatic rearrangements represents the most common genetic alteration in papillary thyroid carcinoma (PTC). Three main rearranged forms of RET have been described: RET/PTC1 and RET/PTC3, which arise from a paracentric inversion of the long arm of chromosome 10, and RET/PTC2, which originates from a 10;17 translocation. We have developed a dual-color FISH approach to detect RET/PTC rearrangements in interphase nuclei of thyroid lesions. By using a pool of three cosmids encompassing the RET chromosome region and a chromosome 10 centromeric probe, we could discriminate between the presence of an inversion (RET/PTC1 and RET/PTC3) or a translocation (RET/PTC2). We have investigated a series of thyroid tissue samples from Italian and French patients corresponding to a total of 69 PTCs and 22 benign lesions. Among PTCs, 13 (18.8%) showed a RET rearrangement, and 11 (15.9%) of these carried an inversion (RET/PTC1 or RET/PTC3) in more than 10% of the nuclei examined. Activated forms of RET were also observed in three adenomas. RT-PCR analysis on the same samples confirmed the presence and the type of rearrangement predicted using FISH analysis. An interesting difference in the frequency and type of RET rearrangements was detected between the Italian and the French patients. Furthermore, we identified a putative novel type of rearrangement in at least one PTC sample. Several PTCs carried a significant number of cells characterized by a trisomy or a tetrasomy of chromosome 10. Overall, the FISH approach in interphase nuclei represents a powerful tool for detecting, at the single cell level, RET/PTC rearrangements and other anomalies involving the RET chromosome region.
FISH-microdissection (FISH-MD) analysis of complex chromosome rearrangements
Authors: Weimer J. , Kiechle M. , Arnold N.
Published: April 2003

We combined the techniques of fluorescence in situ hybridization (FISH) and chromosomal microdissection in one experiment (FISH-MD). This novel method permits rapid identification of the composition, origin, and breakpoints of rearranged chromosomes. Rearranged chromosomes are first identified by multicolor-FISH, then the fluorophore-labeled derivative chromosomes are directly isolated by microdissection and reverse painted to identify the breakpoints.
Localization of new, microdissection- generated, anonymous markers and of the genes Pcsk1, Dhfr, Ndub13, and Ccnb1 to rat chromosome region 2q1
Authors: Quan X. , Laes J.-F. , Ravoet M. , van Vooren P. , Szpirer J. , Szpirer C.
Published: April 2003

The centromeric region of rat chromosome 2 (2q1) harbors unidentified quantitative trait loci of genes that control tumor growth or development. To improve the mapping of this chromosome region, we microdissected it and generated 10 new microsatellite markers, which we included in the linkage map and/or radiation hybrid map of 2q1, together with other known markers, including four genes: Pcsk1 (protein convertase 1), Dhfr (dihydrofolate reductase), Ndub13 (NADH ubiquinone oxidoreductase subunit b13), and Ccnb1 (cyclin B1). To generate anchor points between the different maps, the gene Ndub13 and the microsatellite markers D2Ulb25 and D2Mit1 were also localized cytogenetically. The radiation map generated in region 2q1 extends its centromeric end of about 150 cR.
Comparative cytogenetics of hamsters of the genus Calomyscus
Authors: Graphodatsky A.S. , Sablina O.V. , Meyer M.N. , Malikov V.G. , Isakova E.A. , Trifonov V.A. , Polyakov A.V. , Lushnikova T.P. , Vorobieva N.V. , Serdyukova N.A. , Perelman P.L. , Borodin P.M. , Benda P. , Frynta D. , Leikepová L. , Munclinger P. , Piálek J. , Sádlová J. , Zima J.
Published: April 2003

Karyotypes of Calomyscus from different regions of Turkmenistan, Iran, and Azerbaijan were studied using chromosome banding (G- and C-banding) and analyses of meiosis in laboratory hybrids. Extensive variation in the diploid number and the number of autosomal arms (FNa) was revealed (2n = 30, FNa = 44; 2n = 32, FNa = 42; 2n = 44, FNa = 46; 2n = 44, FNa = 58; 2n = 37, FNa = 44; 2n = 50, FNa = 50; 2n = 52, FNa = 56). Centric and tandem fusions and heterochromatin changes were identified as the major modes of karyotype evolution in this group. Natural hybrids between individuals with different karyotypes were recorded, and regular chromosome pairing in meiosis was observed in laboratory hybrids. Fluorescence in situ hybridization with a 353-bp BspRI complex tandem repeat indicated that chromosomal repatterning occurred recently within the genus. There is no unequivocal evidence suggesting the role of chromosomal change in the speciation of the populations of Calomyscus examined.
Chromosome mapping of the human genes encoding the MAP kinase kinase MEK1 (MAP2K1) to 15q21 and MEK2 (MAP2K2) to 7q32
Authors: Meloche S. , Gopalbhai K. , Beatty B.G. , Scherer S.W. , Pellerin J.
Published: April 2003

Activation of the ERK mitogen-activated protein (MAP) kinase pathway has been implicated in the regulation of cell growth, differentiation and senescence. In this pathway, the MAP kinases ERK1/ERK2 are phosphorylated and activated by the dual-specificity kinases MEK1 and MEK2, which in turn are activated by serine phosphorylation by a number of MAP kinase kinase kinases. We report here the chromosomal localization of the human genes encoding the MAP kinase kinase isoforms MEK1 and MEK2. Using a combination of fluorescence in situ hybridization, somatic cell hybrid analysis, DNA sequencing and yeast artificial chromosome (YAC) clone analysis, we have mapped the MEK1 gene (MAP2K1) to chromosome 15q21. We also present evidence for the presence of a MEK1 pseudogene on chromosome 8p21. The MEK2 gene (MAP2K2) was mapped to chromosome 7q32 by fluorescence in situ hybridization and YAC clone analysis.
Evidence that sex chromosome asynapsis, rather than excess Y gene dosage, is responsible for the meiotic impairment of XYY mice
Authors: Rodriguez T.A. , Burgoyne P.S.
Published: April 2003

There is extensive evidence for the existence of a meiotic checkpoint that acts to eliminate spermatocytes that fail to achieve full sex chromosome synapsis at the pachytene stage of the first meiotic prophase. XYY mice are nearly always sterile, with clear signs of meiotic impairment, and sex chromosome asynapsis has been proposed to underlie this impairment. However, a study of XYY*X mice (mice having three sex chromosomes but only a single dose of Y genes) revealed that these mice are fertile, and thus implicated Y gene dosage as a major factor in the sterility of XYY mice. To address this question further, sex chromosome synapsis and spermatogenic proficiency were compared between XYY*X and XYY mice generated in the same litters. This established that differences in spermatogenic proficiency within and between the two genotypes correlated with the frequency of radial trivalent formation (full sex chromosome synapsis); XYY*X males, as a group, had double the radial trivalent frequency of XYY males. This observation provides strong support for the view that sex chromosome asynapsis (or some consequence thereof), rather than Y gene dosage, is the major factor leading to the meiotic impairment of XYY mice.
Genomic structures and sequences of two closely linked genes (AMT, TCTA) on dog chromosome 20q15.1→q15.2
Authors: Leeb T. , Breen M. , Brenig B.
Published: April 2003

Analysis of genomic sequence from canine chromosome 20q15.1→q15.2 revealed the presence of two closely linked genes. The two genes represent the corresponding canine orthologs of human aminomethyltransferase (AMT) and the human T-cell leukemia translocation associated (TCTA) gene. Aminomethyltransferase or glycine cleavage system T-protein is an important enzyme in glycine metabolism. The reported canine AMT gene spans 5 kb and consists of nine exons. It encodes a protein of 403 amino acids with 88% identity to human aminomethyltransferase. Human TCTA is located on 3p21 near the breakpoint of a t(1;3) translocation observed in some cancer cell lines. The 4-kb canine TCTA gene consists of three exons and probably represents a pseudogene. It is located adjacent to AMT and very close to DAG1 and BSN.
An analysis of meiotic impairment and of sex chromosome associations throughout meiosis in XYY mice
Authors: Mahadevaiah S.K. , Evans E.P. , Burgoyne P.S.
Published: April 2003

The existing XYY meiotic data for mice present a very heterogeneous picture with respect to the relative frequencies of different sex chromosome associations, both at pachytene and diakinesis/metaphase I. Furthermore, where both pachytene and diakinesis/MI data are available for the same males, the frequencies of the different configurations at the two stages are very different. In the present paper we utilise “XYY” and “XY/XYY” mosaic mice with cytologically distinguishable Y chromosomes to investigate the factors responsible for this heterogeneity between different males and between the two meiotic stages. It is concluded (1) that the initial pattern of synapsis is driven by the relatedness of the three pseudoautosomal regions (PARs); (2) that the order and extent of PAR synapsis within radial trivalents are also affected by PAR relatedness and that this leads to chiasmata being preferentially formed between closely related PARs; (3) that trivalents with a single chiasma resolve into a bivalent + univalent by the diakinesis stage; (4) that although many spermatocytes with asynapsed sex chromosomes are eliminated between pachytene and diakinesis, those that survive this phase of elimination progress to the first meiotic metaphase (MI) and accumulate in large numbers, leading to an over-representation of those with univalents as compared to radial trivalents; and (5) that the arrested MI cells are eventually eliminated, so that very few “XYY” cells contribute products to MII.
Histone macroH2A1.2 is concentrated in the XY compartment of mammalian male meiotic nuclei
Authors: Richler C. , Dhara S.K. , Wahrman J.
Published: April 2003

We show here that histone macroH2A1.2 concentrates at the transcriptionally silent XY body, normally being formed during male meiosis in the mouse. A similar accumulation has earlier been observed on the inactive X chromosomes of somatic adult female mammalian cells by Costanzi and Pehrson (1998). This correspondence in the nature of heterochromatinization of the X chromosomes in males and females adds another property of X chromosome inactivation that is shared by males and females at different phases of their life cycle.
cDNA cloning of putative rat acetyl-CoA transporter and its expression pattern in brain
Authors: Bora R.S. , Ichikawa S. , Kanamori A. , Hirabayashi Y.
Published: April 2003

Rat acetyl-CoA transporter gene (Acatn) encodes a hydrophobic multi-transmembrane protein involved in the O-acetylation of gangliosides. O-acetylated gangliosides have been found to play important roles in the embryonic development of the nervous system. We have isolated rat Acatn cDNA by PCR cloning. The amino acid sequence of rat Acatn exhibited 92% and 96% homology with human and mouse sequences, respectively. The mRNA was expressed in brain at all developmental stages. Acatn expression was higher in embryonic and postnatal rats than in adult rats. Cellular localization of Acatn mRNA in adult rat brain was also analyzed by in situ hybridization. Acatn mRNA expression was detected in the neuronal cells of cerebellum, hippocampus, hypothalamus, cortex, olfactory bulb, and dorsal and ventral anterior olfactory nucleus in adult rat brain.
Comparative mapping of seven genes in mouse, rat and Chinese hamster chromosomes by fluorescence in situ hybridization
Authors: Ono T. , Hirano S. , Yonezawa S. , Aono S. , Osaki M. , Masaki S. , Yamashita S. , Tsukasaki T. , Oohira A. , Suzuki S.T. , Sonta S.
Published: April 2003

Abstract. By fluorescence in situ hybridization (FISH) using mouse probes, we assigned homologues for cathepsin E (Ctse), protocadherin 10 (Pcdh10, alias OL-protocadherin, Ol-pc), protocadherin 13 (Pcdh13, alias protocadherin 2c, Pcdh2c), neuroglycan C (Cspg5) and myosin X (Myo10) genes to rat chromosomes (RNO) 13q13, 2q24→q25, 18p12→p11, 8q32.1 and 2q22.1→q22.3, respectively. Similarly, homologues for mouse Ctse, Pcdh13, Cspg5 and Myo10 genes and homologues for rat Smad2 (Madh2) and Smad4 (Madh4) genes were assigned to Chinese hamster chromosomes (CGR) 5q28, 2q17, 4q26, 2p29→p27, 2q112→q113 and 2q112→q113, respectively. The chromosome assignments of homologues of Ctse and Cspg5 reinforced well-known homologous relationships among mouse chromosome (MMU) 1, RNO 13 and CGR 5q, and among MMU 9, RNO 8 and CGR 4q, respectively. The chromosome locations of homologues for Madh2, Madh4 and Pcdh13 genes suggested that inversion events were involved in chromosomal rearrangements in the differentiation of MMU 18 and RNO 18, whereas most of MMU 18 is conserved as a continuous segment in CGR 2q. Furthermore, the mapping result of Myo10 and homologues suggested an orthologous segment of MMU 15, RNO 2 and CGR 2.
Structure and chromosome location of Smtn, the mouse smoothelin gene
Authors: Rensen S. , Merkx G. , Doevendans P. , Geurts van Kessel A. , van Eys G.
Published: April 2003

Smoothelins are cytoskeleton-associated proteins that are found in contractile smooth muscle. Two isoforms have been identified: smoothelin-A, expressed in visceral tissues and smoothelin-B, found in vascular tissues. The mouse smoothelin gene (Smtn) was isolated and characterized. It was assigned to chromosome 11 band A2–A3 by fluorescence in situ hybridization. The gene consists of 20 exons and spans 23 kb. Its structure is conserved between mouse and human. The proximal promoter of both smoothelin-A and smoothelin-B contains several transcription factor-binding sites but lacks a consensus TATA box.
Sex-specific expression of an evolutionarily conserved male regulatory gene, DMRT1, in birds
Authors: Shan Z. , Nanda I. , Wang Y. , Schmid M. , Vortkamp A. , Haaf T.
Published: April 2003

Based on its Z-sex-chromosomal location and its structural homology to male sexual regulatory factors in humans (DMRT1 and DMRT2), Drosophila (Dsx), and Caenorhabditis elegans (Mab-3), chicken DMRT1 is an excellent candidate for a testis-determining factor in birds. The data we present provide further strong support for this hypothesis. By whole mount in situ hybridization chicken DMRT1 is expressed at higher levels in the male than in the female genital ridges during early stages of embryogenesis. Its expression becomes testis-specific after onset of sexual differentiation. Northern blot and RT PCR analysis showed that in adult birds DMRT1 is expressed exclusively in the testis. We propose that two gene dosages are required for testis formation in ZZ males, whereas expression from a single Z chromosome in ZW females leads to female sexual differentiation.
Genomic structure and chromosome mapping of human and mouse RAMP genes
Authors: Derst C. , Engel H. , Grzeschik K.-H. , Daut J.
Published: April 2003

The cDNAs for human and murine Receptor Activity Modifying Proteins and for the associated murine Calcitonin Receptor Like Receptor were isolated. The human RAMP1 and RAMP3 genes possess two introns and human RAMP2 possesses three introns. Human RAMP1 was assigned to chromosome 2q36→q37.1, RAMP2 to 17q12→q21.1 and RAMP3 to 7p13→p12. Mouse Ramp1 was assigned to chromosome 1 and Ramp2 and Ramp3 were assigned to chromosome 11.
Organization of telomere sequences in birds: evidence for arrays of extreme length and for in vivo shortening
Authors: Delany M.E. , Krupkin A.B. , Miller M.M.
Published: April 2003

Telomeres are the specialized ends of chromosomes consisting of highly conserved repeat (5′-TTAGGG-3′)n sequences. Lack of information regarding the existence of an in vivo telomere clock function in birds, conflicting data regarding telomere array length in the chicken model, and the paucity of molecular telomere information for other avian species led us to study telomere array organization within and among 18 species and subspecies of birds. Most of the species contained between 2% and 4% telomere sequence per diploid genome. Arrays spanning 0.5–10 kb (Class I) and 10–40 kb (Class II) were observed in all of the species studied. Extremely long arrays, ranging from hundreds of kilobases to 1–2 Mb (Class III) were observed in all except two raptor species, the northern goshawk and American bald eagle. In chicken, there was evidence for shortening of the Class II arrays in vivo, based on intraindividual comparisons of somatic versus germline tissues in birds of different ages; terminally differentiated erythrocyte arrays were, on average, 2.3 kb shorter than sperm (germline) arrays. This study provides the first evidence for the existence of telomere arrays significantly larger than have been described for any vertebrate species to date and for developmentally programmed in vivo telomere shortening in the Aves taxa. The novel finding of megabase-sized telomere arrays may be an important feature of avian karyotypes that contain a large number of very small genetic units, the microchromosomes.
The human inward rectifier K+ channel subunit Kir5.1 (KCNJ16) maps to chromosome 17q25 and is expressed in kidney and pancreas
Authors: Liu Y. , McKenna E. , Figueroa D.J. , Blevins R. , Austin C.P. , Bennett P. B. , Swanson R.
Published: April 2003

A novel human Kir5.1 (inward rectifier K+ channel subunit, gene name KCNJ16) was identified through database searches. This human KCNJ16 was mapped to chromosome 17q25. The full-length cDNA was identified and its genomic structure was determined. Tissue distribution studies showed that human KCNJ16 is significantly expressed in human kidney, pancreas and thyroid gland. In situ hybridiza- tion revealed expression in convoluted tubule cells of kidney and in the acinar and ductal cells of pancreas. These suggest that human Kir5.1 may be involved in the regulation of fluid and pH balance, thus making it a potential therapeutic target for hypertension, renal failure, or pancreatic disease.
Assignment of transcription factor NFAT5 to human chromosome 16q22.1, murine chromosome 8D and porcine chromosome 6p1.4 and comparison of the polyglutamine domains
Authors: Hebinck A. , Dalski A. , Engel H. , Mattei M.-G. , Hawken R. , Schwinger E. , Zühlke Ch.
Published: April 2003

To date, transcription factors of the NFAT family (nuclear factors of activated T cells) have been described for mouse and man. Recently, we mapped the human NFAT5 gene to chromosome 16 by PCR using DNA from hybrid cell lines. Here we report the exact position of the human gene between D16S496 and WI5254 within the 16q22.1 subband, the localization of the murine gene at chromosome 8D, and the identification and mapping of the porcine counterpart to chromosome 6p1.4.
Reproducibility in Ultrasonic Characterization of Carotid Plaques
Authors: de Bray J.M. , Baud J.M. , Delanoy P. , Camuzat J.P. , Dehans V. , Descamp-Le Chevoir J. , Launay J.R. , Luizy F. , Sentou Y. , Cales P.
Published: April 2003

Background and Purpose: Echolucent carotid plaques compared with echogenic plaques could carry a significant risk of transient ischemic attacks and strokes, but the reproducibility of new ultrasonic methods has not yet been proved. The objective was to evaluate interobserver and intraobserver agreement in characterizing the carotid plaques studied by both B mode imaging and color Doppler imaging, which is the only ultrasonic method available for recognizing anechoic lesions. Methods: Fifty-three carotid plaques greater than 40% in diameter were selected from four centers and simultaneously analyzed by 9 observers. Five types of plaques were defined by their echo structure: class I = uniformly anechogenic, class II = predominantly hypoechogenic with >50% hypoechogenic area, class III = predominantly echogenic with >50% echogenic area, class IV = uniformly echogenic, class V = unclassified plaques. The luminal surface was characterized as either 1 = regular, 2 = recess of more than 2 mm in depth and width, or 3 = unclassified. Agreement of these variables was calculated by using the kappa index, agreement proportion and an intraclass correlation coefficient. Results: Interobserver reproducibility was only fair for type I (kappa = 0.47) and for the luminal surface (class 1, kappa = 0.52 and class 2, kappa = 0.41). Agreement proportion was 0.51 in hypoechoic plaques and 0.64 in the determination of the regular surface. Mean intraobserver agreement was fair (kappa = 0.47 ± 0.1) for plaque echogenicity to good (kappa = 0.63 ± 0.19) for surface. Conclusion: This study shows that the semiquantitative classification, first developed by Gray-Weale, then by Nicolaides, could be improved, thus giving rise to a new outlook in the debated field of ulcerations.
One-Year Follow-Up in Stroke Patients Discharged from Rehabilitation Hospital
Authors: Paolucci Stefano , Grasso Maria Grazia , Antonucci Gabriella , Troisi Elio , Morelli Daniela , Coiro Paola , Bragoni Maura
Published: April 2003

This study was designed to evaluate functional status at a 1-year follow-up in consecutive first-stroke patients after discharge from rehabilitation hospital and to identify reliable prognostic factors associated with changes in their abilities. Functional evaluation was made of consecutive patients 1 year after discharge to their own homes. Two multiple logistic regressions (forward stepwise) were performed using both improvement and worsening of the Barthel Index score between discharge and follow-up as dependent variables. Independent variables were medical, demographic and social factors. The final sample included 157 out of 172 patients. During the follow-up, 10 patients (5.81%) died because of a new cerebrovascular event, 1 patient died of myocardial infarction, 2 patients had new strokes and 2 fractured their paretic legs. Functionally, 43.3% of the patients maintained the level they achieved during inpatient rehabilitation treatment, 23.6% improved and the remaining 33.1% worsened. Patients with hemineglect and aged ≥65 years had a higher probability of functional worsening (odds ratio, OR = 3.77, 95% confidence interval, CI = 1.42– 10.0 and OR = 3.93, 95% CI = 1.72–8.95, respectively). Postdischarge rehabilitation (performed for 46.5% of the final sample) was significantly and positively associated with functional improvement (OR = 7.23, 95% CI = 2.89–18.05), and its absence with functional worsening (OR = 12.32, 95% CI = 4.47–37.01). In conclusion, in nearly half of the cases, functional status was still not stabilized at the time of discharge from the rehabilitation hospital. Postdischarge outpatient treatment was useful for preventing worsening of the functional ability achived during inpatient treatment and increased the possibility of further functional improvement. Age ≥65 years and hemineglect were predictors of functional worsening at follow-up.
Lipoprotein(a), Other Lipoproteins and Hemostatic Profiles in Patients with Ischemic Stroke: The Relation to Cardiogenic Embolism
Authors: Dahl Trond , Kontny Frederic , Slagsvold Carl Erik , Christophersen Bjørn , Abildgaard Ulrich , Ödegaard Ole Rasmus , Mørkrid Lars , Dale Jon
Published: April 2003

Lipoprotein and hemostatic profiles including coagulation inhibitors were determined in 136 patients with acute ischemic stroke. Based on clinical examination, cerebral computed tomography, Doppler ultrasonography of precerebral arteries and transthoracic echocardiography, the strokes were classified as cardioembolic (n = 38), non-cardioembolic (n = 92), and mixed cardioembolic/hypertensive (n = 6). Patients with cardioembolic stroke were older than patients with non-cardioembolic stroke. Lipoprotein(a) was higher in the cardioembolic than in the non-cardioembolic group. Lipoprotein(a) was not significantly correlated to the other lipid levels and may represent an independent lipid risk factor. The non-cardioembolic group had higher levels of total cholesterol, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, low-density lipoprotein cholesterol, apolipoprotein A1, and apolipoprotein B. The cardioembolic group had higher concentrations of fibrinogen and D-dimer, and lower levels of antithrombin, protein C, protein S and heparin cofactor 2 than the non-cardioembolic group. The differences in the hemostatic profile are consistent with thrombosis due to activated coagulation being more involved in the pathogenesis of cardioembolic than of non-cardioembolic stroke. Lipoprotein(a) seems to be more associated with coagulation markers of thrombosis than with atherosclerosis, whereas the other lipids mainly seem to be risk factors for atherosclerosis.
The Carotid Compression Test for Therapeutic Occlusion of the Internal Carotid Artery
Authors: Hetzel A. , von Reutern G.-M. , Wernz M.G. , Droste D.W. , Schumacher M.
Published: April 2003

Background: The anterior communicating artery is a key collateral pathway in patients with internal carotid artery (ICA) occlusions. Diagnostic balloon or manual occlusion of the ICA is a qualified test for the collateral function of the circle of Willis. The aim of our study was to test whether transcranial Doppler sonography (TCD) with manual carotid compression is able to predict the degree of cross-over flow and tolerance of ICA occlusion. Methods: A prospective study was performed on 88 patients suffering from neck tumors or inoperable ICA aneurysms with planned ligation or permanent balloon occlusion of the ICA. Preceding a balloon occlusion lasting 20 min we performed TCD with manual carotid compression test. Insufficient cross-over flow during transient carotid occlusion was defined angiographically as missing opacification of the middle cerebral artery (MCA) after selective injection of contrast media in the contralateral ICA, and sonographically as a decrease greater than 60% in flow velocity of the MCA ipsilateral to the carotid occlusion. Results: TCD and angiography could be compared in 70 of 88 patients. Angiography showed no or insufficient collateral flow in 26%. All patients (n = 10) with a decrease in MCA velocity greater than 60% on angiography showed missing or poor cross-over flow. A greater than 50% increase in the anterior cerebral artery (ACA) predicted moderate or good cross-over flow in 98%. Clinical observation revealed 11 transient neurological deficits. Eight of them showed insufficient cross-over flow angiographically and sonographically. In 2 of 11 only TCD revealed such low collateral supply. Neither technique predicted hemodynamic ischemia in only 1 of the 11. Conclusion: TCD with carotid compression test is a valid method for predicting interhemispheric flow and clinically relevant hemodynamic compromise in cases of occlusion of the ICA.
Microembolic Signal Monitoring in Hemispheric Acute Ischaemic Stroke: A Prospective Study
Authors: Serena Joaquín , Segura Tomás , Castellanos Mar , Dávalos Antoni
Published: April 2003

Background and Purpose: There are few data on the occurrence of microembolic signals (MES) in the acute phase of ischaemic stroke. The objective of our work was to systematically study the frequency of MES in non-selected patients with a first-ever hemispheric transient ischemic attack (TIA) or acute cerebral infarction, and to evaluate the clinical usefulness of MES detection. Methods: 182 consecutive patients with hemispheric TIA or acute cerebral infarction, and 54-age-matched healthy controls were studied. Bilateral transcranial Doppler ultrasound (TCD) monitoring was performed for at least 30 min with a mean time from stroke onset to TCD of 69 h. Stroke severity on admission, early recurrent stroke and dependency on discharge were investigated. Results: MES were detected in 20.5% of patients with arterial sources of embolism, 17.1% of patients with potential sources of cardioembolism and 5% of patients with cryptogenic stroke. They were not registered, however, in lacunar infarctions (p < 0.001). Stroke severity on admission of patients with MES was greater than that of patients without MES (47.1 vs. 19.4% with the Canadian Stroke Scale ≤6.5; p = 0.009). Early recurrent stroke was more frequent in patients with MES (11.8%) than in those without MES (4.2%) although the difference was not statistically significant. Multiple logistic regression analysis showed that MES increased the risk of dependency on discharge (odds ratio, 4.2; 95% CI, 1.2–14.9; p = 0.01) independently of age, stroke severity on admission and presence of an arterial or cardiac embolic source. Conclusions: There is a strong association of MES in the acute phase of stroke with known potential arterial and cardiac embolic sources. MES have an independent predictive value of poor outcome.
Serum Amino Acid Levels after Permanent Middle Cerebral Artery Occlusion in the Rat
Authors: Puig Núria , Dávalos Antoni , Adan Jaume , Piulats Jaume , Martínez Josep Maria , Castillo José
Published: April 2003

Background and Purpose: High levels of glutamate in plasma and cerebrospinal fluid (CSF) have been demonstrated in patients with acute ischemic stroke. Whereas this glutamate increase in CSF is only evidenced during the first 6 h in stable ischemic stroke, it is sustained for 24 h in progressing stroke. The aim of this investigation was to study the evolution of serum glutamate levels after stroke in a rat model of permanent cerebral artery occlusion. Methods: Glutamate, glycine, aspartate, taurine and tryptophan were measured by high-performance liquid chromatography from serum samples taken before and at different times after permanent middle cerebral artery occlusion (MCAO) and from sham-operated rats. Results: After MCAO, a 3-fold increase in glutamate and a 2-fold increase in glycine and aspartate were observed in rat serum. The onset of this amino acid increase began 4–6 h after ischemic induction, reached peak values at 8–24 h and returned to preischemic values by 48–72 h. Serum concentrations of taurine and tryptophan were not modified after MCAO. Sham-operated rats did not exhibit changes of basal amino acid concentrations in serum. Conclusions: The serum excitatory amino acid profile in this experimental model confirms that the early detection of increased concentrations of glutamate and glycine at systemic circulation observed in patients with acute stroke is a consequence of the cerebral ischemic process.
The History of Community Genetics: The Contribution of the Haemoglobin Disorders
Authors: Modell Bernadette , Kuliev Anver
Published: April 2003

The emerging possibilities of applying new diagnostic technologies for genetic diagnosis and screening point to the need for a discipline of community genetics. Genetic population screening for haemoglobin disorders (thalassaemias and sickle cell disorders) has been practised on a large scale for over 20 years, and basic concepts and methods of community genetics have been developed within this framework, under the auspices of the WHO. Genetic population screening is a public health activity. It involves many disciplines, and planning depends on reliable and regularly updated information. Basic methods for describing genetic epidemiology in terms of service needs, and for regular service audit have been developed, and IT-based approaches for making simple, accurate and diagnosis-specific information accessible to the public and health professionals are being explored.