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Biomedical subjects

S Brenner

Publications and source records attributed to S Brenner.

At least 397 records · Page 22Linked to original sources
PubMed1980

Novel bacteriophage lambda cloning vector.

A simple method for generating phage collections representing eukaryotic genomes has been developed by using a novel bacteriophage lambda vector, lambda 1059. The phage is a BamHI substitution vector that accommodates DNA fragments 6-24 kilobases long. Production of recombinants in lambda 1059 requires deletion of the lambda red and gamma genes. The recombinants are therefore spi- and may be separated from the spi+ vector phages by plating on strains lysogenic for bacteriophage P2. Random fragments suitable for insertion into lambda 1059 are obtained by partial digestion of high molecular weight eukaryotic DNA with Sau3a. This restriction enzyme cleaves at the sequence G-A-T-C and leaves a 5'-tetranucleotide "sticky end." Because G-A-T-C extensions are also produced by BamHI cleavage, these fragments may be annealed directly to BamHI-cleaved lambda 1059. By using these methods, a set of clones covering the entire Caenorhabditis elegans genome was constructed. DNA segments which include the unc-54 myosin heavy chain gene have been isolated from this collection.

Animals↗
PubMed1979

Partial purification of tumour-specific transplantation antigens from methylcholanthrene-induced murine sarcomas by immobilized lectins.

Plasma membranes isolated from two immunogenic, non-cross-protecting, MC sarcomas were shown to retain the specific rejection antigens of whole cells as well as serologically detected H-2 antigens. Solubilization of the membranes with sodium deoxycholate gave quantitative release of H-2 and retained the rejection specificity of the tumour from which it was derived. Polyacrylamide-gel electrophoresis (PAGE) showed no extensive degradation of membrane components during solubilization. The solubilized TSTAs were further characterized and purified on columns of 4 different lectins immobilized on sepharose beads. TSTA from both tumours bound to WGA but not to Con A, LCH or RCA columns. Specific activity was retained after elution from the WGA column. Serologically detectable H-2 bound to the Con A and LCH columns only. Clear separation of H-2 from TSTA activity was thus obtained. Furthermore the WGA-binding material represents a source for further purification of TSTA molecules in order to explore the basis for their diversity.

Animals↗
PubMed1978

A suppressor mutation in the nematode acting on specific alleles of many genes.

A suppressor mutation has been isolated in Caenorhabditis elegans through reversion analysis of a muscle-defective mutant. The suppressor mutation acts on specific alleles of at least six genes and in one case we have been able to show that it partially restores functional gene product to a mutant otherwise lacking that product. These and other features of the suppressor suggest that it acts at some step in information transfer, perhaps through mechanisms similar to those described previously in microorganisms.

Alleles↗
PubMed1978

Indirect suppression in Caenorhabditis elegans.

Two cases of indirect suppression have been characterized. One case involves suppressors compensating for defects in muscle structure. Nine independent suppressor mutations were judged to lie in a single suppressor gene, sup-3. Suppression is dominant, but dose dependent, and results in improved locomotion, as well as in an increase in the ability of mutant animals to lay eggs. Mutations in six genes known to affect muscle structure were tested for suppression by representative sup-3 mutations. Alleles of three of the six genes are suppressed, two of which are known to code for thick filament proteins. One suppressor allele was identified as a deletion by genetic criteria. A second case of indirect suppression is not associated with muscle defects, but involves two mutant genes producing uncoordinated phenotypes very similar to one another. As in the first case, suppression is dominant but dose dependent and is not allele specific.

Alleles↗
PubMed1978

HLA antigens in patients with psoriasis.

Tissue typing was performed on lymphocytes of 46 Jewish patients with psoriasis vulgaris. HLA B13, B17, B37 and Cw6 were found increased. It is suggested that the increase in the B and C locus antigens is inter-related and may determine the genetic predisposition for the development of this disease.

Epitopes↗
PubMed1977

An internal deletion mutant of a myosin heavy chain in Caenorhabditis elegans.

Unc-54 I is the structural gene for a myosin heavy chain present in a major fraction of the total myosin of Caenorhabditis elegans. The allele e675, which possesses a normal amount of myosin but fails to assemble thick filaments, has been shown previously to contain a novel heavy chain of molecular weight 2 X 10(5), shorter by 10(4) than the wild-type (N2) unc-54 gene product. The structural alteration of the E675 heavy chain is an internal deletion of 10(4) molecular weight near the COOH terminus of the molecule. This has been determined by mapping the partial digestion products of heavy chain fragments labeled specifically at their NH2 termini.

Chromosome Deletion↗