Search results for "Restriction Mapping"
showing 10 items of 76 documents
Systematic screening for mutations in the human serotonin-2A (5-HT2A) receptor gene: Identification of two naturally occurring receptor variants and …
1996
A statistically significant association between a silent mutation (102T/C) in the serotonin-2A (5-HT2A) receptor gene and schizophrenia has recently been reported in a sample of Japanese patients and healthy controls. This finding suggests that genetic predisposition to schizophrenia may be affected by a functional 5-HT2A receptor variant that is in linkage disequilibrium with 102T/C. In the present study, we have sought to identify genetic variation in the 5-HT2A receptor gene by screening genomic DNA samples from 91 unrelated subjects comprising 45 patients with schizophrenia and 46 healthy controls by using single-strand conformation analysis. We have identified four nucleotide sequence …
Molecular cloning and nucleotide sequence of chicken avidin-related genes 1-5.
1994
Using avidin cDNA as a hybridisation probe, we detected a gene family whose putative products are related to the chicken egg-white avidin. Two overlapping genomic clones were found to contain five genes (avidin-related genes 1–5, avrl-avr5), which have been cloned, characterized and sequenced. All of the genes have a four-exon structure with an overall identity with the avidin cDNA of 88–92%. The genes appear to have no pseudogenic features and, in fact, two of these genes have been shown to be transcribed. The putative proteins share a sequence identity of 68–78% with avidin. The amino acid residues responsible for the biotin-binding activity of avidin and the bacterial biotin-binding prot…
Closing in on the toxic domain through analysis of a variant Clostridium difficile cytotoxin B
1995
Strain 1470 is the standard typing strain for serogroup F of Clostridium difficile containing both toxin genes, toxA-1470 and toxB-1470. A polymerase chain reaction (PCR)-based approach to the sequencing of the total toxB-1470 gene identified an open reading frame (ORF) of 7104 nucleotides. In comparison with the previously sequenced toxB of C. difficile VP10463, the toxB-1470 gene has 16 additional nucleotides, 13 within the 5'-untranslated region and three within the coding region. The M(r) of ToxB-1470 is 269,262, with an isoelectric point (IP) of 4.16. The equivalent values for ToxB are M(r) 269,709 and IP 4.13. In comparison with ToxB, ToxB-1470 differs primarily in the N-terminal regi…
No evidence for sequences structurally related to the RB1 gene in the human genome.
1991
The retinoblastoma (RB1) gene is a ubiquitously expressed gene encoding a cell-cycle control protein. Inactivation of this gene plays a crucial role in the development of retinoblastoma, osteosarcoma, and other tumors. In a search for structurally related gene sequences we identified a 5.5-kb BamHI fragment strongly cross-hybridizing with the 5′ end of the RB1 cDNA. Molecular cloning, in situ hybridization, restriction mapping, and sequence analysis identified this DNA segment as the 28S rRNA gene. The absence of other cross-hybridizing sequences suggests that the RB1 gene is not part of a structurally related gene family.
One gene, two transcripts: isolation of an alternative transcript encoding for the autoantigen La/SS-B from a cDNA library of a patient with primary …
1994
A cDNA library was prepared from peripheral blood lymphocytes of an autoimmune patient with primary Sjögrens' syndrome. The cDNA library was screened with the patients own autoimmune serum being monospecific for the nuclear autoantigen La/SS-B. Thereby an alternative type of La mRNA was identified that differed from the known La mRNA due to an exchange of the exon 1. Sequencing of the genomic region between the exons 1 and 2 showed that the alternative 5'-end is a part of the intron. In addition, the presence of an alternative promoter site, which exists within the intron downstream of the exon 1, became evident. In consequence, the alternative La mRNA is the result of a promoter switching …
Chromatin structure of transposon Tn903 cloned into a yeast plasmid
1989
Transposon Tn903 contains the APH gene for kanamycin resistance, which is active in yeast [A. Jiménez and J. Davies (1980) Nature (London) 287, 869-871] and is flanked by two inverted repeats (IR) 1057 bp long. When plasmid pAJ50, carrying Tn903 and the 2-microns circle origin of replication, is cloned into Saccharomyces cerevisiae, nucleosomes are assembled in vivo on the prokaryotic DNA of the transposon. Indirect end labeling revealed that three nucleosomes are preferentially positioned on symmetrical sequences from both IRs. DNase I digestion also confirmed that the chromatin structure is symmetrical in both IRs. This suggests that sequence determinants are decisive for chromatin struct…
P sequences ofDrosophilla Subobscuralack exon 3 and may encode a 66 kd repressor-like protein
1991
Abstract Several P homologous sequences have been cloned and sequenced from Drosophila subobscura. These sequences are located at the 85DE region of the O chromosome and at least three of them are organized in tandem. We have identified four copies which exhibit strong similarity between them. All of the isolated elements are truncated at the 5' and 3' ends. They have lost the inverted terminal repeats and exon 3, but maintain exons 0, 1 and 2. They are transcribed producing a polyadenylated RNA. The structure of these transcripts suggests that they are able to encode a 66 kd repressor-like protein, but not a functional transposase. We ask about the biological role of a potential repressor …
The Mu1 transposable element of maize contains two promoter signals recognized by the Escherichia coli RNA polymerase.
1990
The galactokinase (GalK) expression plasmid vector system pKO-1 has been used to screen for promoter elements in the maize transposable element Mu1 that function in Escherichia coli. Two transcriptional start points, named S1 and S2, were identified, which are located in the two direct repeats of the transposable element. This paper demonstrates that sequence elements exist in a plant transposable element which function as prokaryotic promotors.
The Suppressor of fused Gene Encodes a Novel PEST Protein Involved in Drosophila Segment Polarity Establishment
1995
Abstract Suppressor of fused, Su(fu), was identified as a semi-dominant suppressor of the putative serine/threonine kinase encoded by the segment polarity gene fused in Drosophila melanogaster. The amorphic Su(fu) mutation is viable, shows a maternal effect and displays no phenotype by itself. Su(fu) mutations are often found associated to karmoisin (kar) mutations but two complementation groups can be clearly identified. By using a differential hybridization screening method, we have cloned the Su(fu) region and identified chromosomal rearrangements associated with Su(fu) mutations. Two classes of cDNAs with similar developmental patterns, including a maternal contribution, are detectable …
Characterization of a new member of the sea urchin Paracentrotus lividus hsp70 gene family and its expression
1992
We have sequenced a second gene of the hsp70 family derived from a genomic clone of the sea urchin, Paracentrotus lividus. The structure of this gene, named hsp70IV gene, is interrupted by one intron and differs from the previously analyzed sea urchin hsp70II gene, which contains several introns. Two open reading frames of hsp70IV gene encode a predicted protein of 639 amino acids with an M(r) of 69,672. The 5' flanking region of the gene contains a putative TATA element, three heat-shock elements made up of some arrays of the 5-bp units, NGAAN and NTTCN (N = A,C,G or T), a canonic consensus sequence for binding of the regulatory activating transcription factor (ATF), and a purine box. The …