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D C Ward

Publications and source records attributed to D C Ward.

At least 109 records · Page 6Linked to original sources
PubMed1993

Localization of a highly conserved human potassium channel gene (NGK2-KV4; KCNC1) to chromosome 11p15.

Several genes (the Shaker or Sh gene family) encoding components of voltage-gated K+ channels have been identified in various species. Based on sequence similarities Sh genes are classified into four groups or subfamilies. Mammalian genes of each one of these subfamilies also show high levels of sequence similarity to one of four related Drosophila genes: Shaker, Shab, Shaw, and Shal. Here we report the isolation of human cDNAs for a Shaw-related product (NGK2, KV3.1a) previously identified in rat and mice. A comparison of the nucleotide and deduced amino acid sequence of NGK2 in rodents and humans shows that this product is highly conserved in mammals; the human NGK2 protein shows over 99% amino acid sequence identity to its rodent homologue. The gene (NGK2-KV4; KCNC1) encoding NGK2 was mapped to human chromosome 11p15 by fluorescence in situ hybridization with the human NGK2 cDNAs.

Amino Acid Sequence↗
PubMed1993

Human myosin-binding protein H (MyBP-H): complete primary sequence, genomic organization, and chromosomal localization.

Vertebrate striated muscle contains a set of myosin-associated proteins with discrete distributions in the A-band. Some of these proteins, including MyBP-H and MyBP-C, are characterized by a series of internal repeats (motifs) with homology to either the C2-set of the immunoglobulin superfamily or the fibronectin type III repeat. These repeats are predicted to be involved in protein-protein interactions within the myofibril. The cDNA sequence, the genomic organization, and the chromosomal localization of the human homologue of MyBP-H are presented. The 1.8-kb cDNA encodes a 52-kDa polypeptide containing two Ig-C2 and two type III repeats. The mRNA is expressed in a skeletal muscle-specific pattern. A 28-kb region of genomic sequence has been isolated that encompasses the 5' and 3' ends of the cDNA. This region includes 4.2 kb of upstream sequence with a potential promoter and 14 kb of downstream sequence containing the polyadenylation site. The chromosomal assignment was made by high resolution chromosomal in situ hybridization. This method maps the gene to chromosome 1q32.1. The repeat structure described previously in chicken MyBP-H and MyBP-C was also detected in human MyBP-H. The primary sequence of the C-terminal Ig-C2 motif and its predicted secondary structure have been extensively conserved in MyBP-H homologues and other members of the MyBP family. This Ig-C2 motif has been implicated in myosin binding.

Amino Acid Sequence↗
PubMed1993

Isolation and FISH mapping of 80 cosmid clones on the short arm of human chromosome 3.

We have isolated and mapped by fluorescence in situ hybridization 80 new cosmids on the short arm of chromosome 3. These markers were isolated from a radiation-reduced hybrid, DM1, made from a cell line that was monochromosomal for human chromosome 3. Selected cosmids were used in double-label cohybridization experiments in which polymerase chain reaction products, generated by an Alu oligonucleotide primer from genomic DNA, were used for chromosome banding. Fifty-six of the cosmid probes map between 3p14.3 and 3p22 while 24 other probes cluster around bands 3p23-3p25. Three probes that appeared to map close to the chromosome 3 region bearing a t(3,8)p14.2; q24.1 translocation associated with renal cell carcinoma were analyzed by interphase mapping techniques and hybridized to metaphase spreads from the translocation cell line. These 80 probes will be useful in the elucidation of genetic alterations associated with diseases such as small cell lung carcinoma, renal cell carcinoma, and von Hippel-Lindau disease.

Animals↗
PubMed1993

Fluorescence in situ hybridization mapping of 25 markers on distal human chromosome 2q surrounding the human Waardenburg syndrome, type I (WS1) locus (PAX3 gene).

A total of 25 DNA markers located on the long arm of human chromosome 2 have been mapped by fluorescence in situ hybridization. This region includes the locus for Waardenburg syndrome, type I (WS1), recently found to result, at least in some cases, from mutations of the PAX3 gene. We have established that the chromosomal location of the PAX3 gene is within band 2q36. We also show that three markers in the distal 2q region, including the PAX3 gene, are deleted in a patient with phenotypic features of WS1 associated with a de novo deletion (2)(q35q36.2). The improved physical map of this region should facilitate linkage mapping and positional cloning of loci on distal 2q.

Base Sequence↗
PubMed1993

Assignment of the human GTF2F1 gene to chromosome 19p13.3.

TFIIF (also termed FC) is a general transcription initiation factor that binds to RNA polymerase II and recruits it to a promoter. TFIIF is a heterodimer composed of 74-kDa (RAP74; gene symbol GTF2F1) and 30-kDa (RAP30; gene symbol GTF2F2) subunits. Here we report the mapping of the human GTF2F1 gene to band 19p13.3. Localization was performed by fluorescence in situ hybridization using the human RAP74 genomic cosmid clone as the probe.

Chromosome Banding↗
PubMed1993

Physical and genetic maps for chromosome 10.

A fluorescence in situ hybridization (FISH) physical map of 14 polymorphic loci on chromosome 10 covers over 62% of the fractional length of chromosome 10. The positions of three previously mapped loci are confirmed, nine more are refined, and two new loci are cytogenetically mapped. The order of loci determined by FISH agrees with that obtained by genetic linkage studies. When the distance estimates for the physical map are compared to the distance estimates of our existing linkage map, the sex average ratio of the fractional length (FL) per centimorgan (cM) for this portion of chromosome 10 is 0.004 (or 0.4% FL/cM). However, the average ratios for male- and female-specific genetic distances are quite different, in agreement with an overall higher rate of recombination in females (0.008 FL/cM and 0.003 FL/cM, respectively). Moreover, the ratio across the centromere is larger for both the male (0.031 FL/cM) and the female (0.009 FL/cM) than the ratio encompassing the q arm (0.006 FL/cM for males and 0.002 FL/cM for females), suggesting that there is reduced recombination at the centromere in both the male and the female maps when compared to the physical distance generated from FISH on metaphase chromosomes.

Chromosome Mapping↗
PubMed1993

Chromosome mapping of five human cardiac and skeletal muscle sarcoplasmic reticulum protein genes.

Fluorescence in situ hybridization (FISH) experiments were performed using genomic and complementary DNA probes in order to determine the location on human chromosomes for five genes expressed in cardiac and skeletal muscle sarcoplasmic reticulum. The chromosome location of each gene was determined in terms of both cytogenetic bands and fractional chromosome length. The ATP2A2 gene, expressing the SERCA2 isoform of the Ca2+ pump, maps to bands 12q23-q24.1, the phospholamban gene (PLN) to 6q22.1, the human skeletal muscle calsequestrin gene (CASQ1) to band 1q21, the cardiac calsequestrin gene (CASQ2) to bands 1p11-p13.3, and the cardiac calcium release channel gene (RYR2) to the interval between band 1q42.1 (distal) and band 1q43 (proximal).

Adenosine Triphosphatases↗
PubMed1993

Genomic and yeast artificial chromosome long-range physical maps linking six loci in 10q11.2 and spanning the multiple endocrine neoplasia type 2A (MEN2A) region.

Multiple endocrine neoplasia types 2A and 2B (MEN 2A and MEN 2B) and familial medullary thyroid carcinoma (FMTC) are dominantly inherited cancers that have in common the clinical feature of medullary thyroid carcinoma (MTC). We have performed both genomic long-range restriction mapping and yeast artificial chromosome (YAC) contig assembly and restriction mapping to establish physical linkage, order, and distances between six loci in 10q11.2 near the genes responsible for these hereditary cancers. RET, D10S94, D10S182, and D10S102 have been mapped in genomic DNA. RET, D10S94, D10S182, D10F38S3, and the 10q11.2 sequences detected by DNA marker DM124 are encompassed by a 1-Mb YAC contig. Six physically linked loci are within 1.4 Mb and have an order and orientation of 10cen, D10F38S3, DM124, RET, D10S94, D10S182, D10S102, 10qter. Mutations in the RET proto-oncogene have recently been demonstrated to be associated with MEN 2A and FMTC. RET is located within a genetically defined MEN2A candidate interval between D10S141 and D10S94; MEN2B has been mapped to a larger, overlapping region between D10S141 and a more distal locus, RBP3. Both our genomic physical map and our YAC contig span the entire MEN2A candidate region and overlap with that of MEN2B. These maps will facilitate the identification of genes that can be considered candidates for MEN2B and the identification of tumor-specific alterations important in sporadic MTC.

Base Sequence↗
PubMed1993

Physical delineation of the minimal chromosomal segment encompassing the murine host resistance locus Bcg.

The host resistance locus Bcg determines resistance of mice to infection with intracellular pathogens such as certain species of Mycobacteria, Salmonella typhimurium, and Leishmania donovani. Bcg maps on the proximal portion of mouse chromosome 1, very tightly linked to villin (Vil), with the gene order and intergene distances Tp-1-(1 cM)-D1Mcg105-(0.1 cM)-lambda Mm1C165/Vil/Bcg-(0.2 cM)-lambda Mm1C136-(0.3 cM)-Des-(0.1 cM)-Inha. In an effort to clone genomic sequences overlapping Bcg, we have used pulsed-field gel electrophoresis (PFGE) and fluorescence in situ hybridization to construct a physical map of the 3.9-Mb segment of proximal mouse chromosome 1, near Bcg. In situ hybridization to metaphase mouse chromosomes indicates that the mapped region is within band C5. Physical mapping of the Tp-1-Vil and lambda Mm1C136-Inha intervals was carried out by PFGE analysis, whereas the Vil-Des interval was estimated by in situ hybridization to interphase nuclei. Results of these combined analyses indicate the following locus order and maximal interlocus distances: Tp-1-(1000 kb)-D1Mcg105-(160 kb)-lambda Mm1C165-(180 kb)-Vil-(800 kb)-lambda Mm1C136-(290 kb)-Des-(130 kb)-Inha. Detailed restriction mapping of this region identifies numerous putative CpG islands, suggesting that several transcription units are present in the vicinity of Bcg.

Animals↗
PubMed1993

Characterization of two chromosome 12 cosmid libraries and development of STSs from cosmids mapped by FISH.

We have constructed and characterized two related human chromosome 12-specific cosmid libraries. DNA from flow-sorted chromosomes from a somatic cell hybrid was cloned into a cosmid vector. Approximately 61% of the cosmids in the nearly 26,200 member arrayed libraries (LL12NC01 and LL12NC02) contain human DNA inserts, and 31% of the cosmids derived from human DNA contain CA repeats. One hundred and fifty-two cosmids isolated from the libraries have been mapped by fluorescence in situ hybridization (FISH). Cosmids containing human DNA inserts were localized by FISH exclusively to chromosome 12, confirming the chromosomal specificity of the libraries. The cosmids have been localized to all parts of this chromosome, although some regions are more highly represented than others. Partial sequence information was obtained from 44 mapped cosmids, and oligonucleotide primer pairs were synthesized that define unique sequence tagged sites (STSs). These mapped cosmids, and unique STSs derived from them, provide a set of useful clones and primer pairs for screening YAC libraries and developing contigs centered on regions of interest within chromosome 12. In addition, 120 of the mapped cosmids contain CA repeats, and thus they also provide a useful resource for defining highly polymorphic simple tandem repeat elements that serve as genetic markers for linkage analysis and disease gene localization.

Base Sequence↗
PubMed1993

Comparative high-resolution mapping of human and primate chromosomes by fluorescence in situ hybridization.

A molecular cytogenetic approach that facilitates high-resolution comparative mapping of defined human genes in different primate species is presented. Fluorescence in situ hybridization and digital imaging microscopy were used to visualize human DNA probes on simultaneously banded or "painted" metaphase chromosomes of great apes (Pan troglodytes, Gorilla gorilla, Pongo pygmaeus), hylobatids (Hylobates lar and Hylobates syndactylus), and Old World monkeys (Macaca fuscata and Cercopithecus aethiops). Using a series of DNA probes, chromosomal rearrangements in the karyotypes of primates were readily detected at the molecular cytogenetic level. This approach should contribute considerably to the understanding of primate phylogeny and evolution.

Animals↗
PubMed1993

An alphoid DNA sequence conserved in all human and great ape chromosomes: evidence for ancient centromeric sequences at human chromosomal regions 2q21 and 9q13.

Using vector-CENP-B box polymerase chain reaction (PCR) we isolated and cloned from a human chromosome 21-specific plasmid library, a 1 kb DNA sequence, named p alpha H21. In in situ hybridization experiments, p alpha H21 hybridized, under high stringency conditions, to the centromeric region of all the human, chimpanzee, gorilla and orangutan chromosomes. On human chromosomes p alpha H21 also identified non-centromeric sequences at 2q21 (locus D2F33S1) and 9q13 (locus D9F33S2). The possible derivation of these sequences from ancestral centromeres is discussed. Sequence analysis confirmed the alphoid nature of the whole p alpha H21 insert.

Animals↗
PubMed1993

A new polymorphic marker (D10S97) tightly linked to the multiple endocrine neoplasia type 2A (MEN2A) locus.

Familial multiple endocrine neoplasia type 2A (MEN 2A) is a cancer syndrome that is inherited as an autosomal dominant with high penetrance. Its clinical features are medullary carcinoma of the thyroid, pheochromocytomas, and hyperparathyroidism. A new polymorphic locus D10S97 (probe: KW6 delta SacI) detects a codominant EcoRI polymorphism that is tightly linked to the MEN2A locus. The peak lod score for linkage between D10S97 with MEN2A is 13.03 at theta = 0.00. The polymorphic locus D10S97 maps, by linkage analysis, into the previously defined interval between FNRB and RBP3 to which MEN2A has been assigned. We present physical mapping data showing that the probe pKW6 originates from 10p13 and that the polymorphic locus D10S97 in 10q11.2 is detected by cross-hybridization.

Animals↗
PubMed1993

Molecular characterization of a pericentric inversion in mouse chromosome 8 implicates telomeres as promoters of meiotic recombination.

A "hot spot" of meiotic recombination has been found in males on murine chromosome 8 using nonisotopic hybridization of a series of probes to mitotic and meiotic chromosomes. The sequences responsible for this enhanced recombination are the telomeric repeats. Mice both normal and hetero- or homozygous for a pericentric inversion, In(8)1 Rl, were analyzed. The inversion subdivides chromosome 8 into three discreet regions: (1) a fraction of the micro "short arm" that contains 30-150 kb of telomeric sequences and only about one-fifth of the contiguous minor-satellite sequences (approximately 200 kb); (2) the inverted region; and (3) the noninverted distal two-thirds of the chromosome. In 70 spermatocytes from inversion heterozygotes, examined by electron microscopy, synapsis of the inverted region was complete but entirely nonhomologous. Nonhomologous synapsis persists from initiation of synaptonemal complex formation in zygonema/early pachynema until dissolution in late pachynema. This nonhomologous synapsis also suppresses crossing over within the inverted segment. The opportunity for proximal homologous recombination is thus restricted to the roughly 250 kb segment located between the short-arm break and the end of the bivalent. Nonetheless, an extreme proximal chiasma was observed in 11% of the heterozygous chromosome-8 bivalents, 34% of the normal 8 bivalents and 35% of the homozygous inversion 8 bivalents from spermatocyte preparations. Since in the normal chromosomes all minor satellite sequences are adjacent to the telomere, while in the inversion chromosomes most of these sequences are transposed to an interstitial position without a corresponding shift in chiasma position, the minor-satellite sequences can be ruled out as promoters of recombination.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Localization of Shaw-related K+ channel genes on mouse and human chromosomes.

Four related genes, Shaker, Shab, Shaw, and Shal, encode voltage-gated K+ channels in Drosophila. Multigene subfamilies corresponding to each of these Drosophila genes have been identified in rodents and primates; this suggests that the four genes are older than the common ancestor of present-day insects and mammals and that the expansion of each into a family occurred before the divergence of rodents and primates. In order to define these evolutionary relationships more precisely and to facilitate the search for mammalian candidate K+ channel gene mutations, we have mapped members of the Shaw-homologous gene family in humans and mice. Fluorescence in situ hybridization analysis of human metaphase chromosomes mapped KCNC2 (KShIIIA, KV3.2) and KCNC3 (KShIIID, KV3.3) to Chromosome (Chr) 19q13.3-q13.4. Inheritance patterns of DNA restriction fragment length variants in recombinant inbred strains of mice placed the homologous mouse genes on distal Chr 10 near Ms15-8 and Mdm-1. The mouse Kcnc1 (KShIIIB, NGK2-KV4, KV3.1) gene mapped to Chr7 near Tam-1. These results are consistent with the hypothesis that the generation of the mammalian KCNC gene family included both duplication events to generate family members in tandem arrays (KCNC2, KCNC3) and dispersion of family members to unlinked chromosomal sites (KCNC1). The KNCN2 and KCNC3 genes define a new synteny group between humans and mice.

Animals↗
PubMed1993

The human cytochrome b5 gene and two of its pseudogenes are located on chromosomes 18q23, 14q31-32.1 and 20p11.2, respectively.

Using very high stringency hybridization conditions for the Southern blot hybridization analysis of hamster-human cell hybrid DNA, we were able to map the human cytochrome b5 gene and two of its pseudogenes (psgb(5)1 and psgb(5)2) unambiguously to chromosomes 18, 14, and 20. These localizations were confirmed and extended to 18q23, 14q31-32.1, and 20p11.2 by using a combination of nonisotopic in situ hybridization of chromosomal spreads and the polymerase chain reaction analysis of DNA samples isolated from somatic cell hybrids retaining deletions or translocations of chromosome 18.

Animals↗