Identification of a yeast snRNP protein and detection of snRNP-snRNP interactions.

The RNA8 gene of Saccharomyces cerevisiae encodes an unusually large (260 kd) protein required for pre-mRNA splicing. Immunological procedures have been used to demonstrate that the RNA8 protein is in stable association with the small nuclear RNAs snR7L and snR7S, which are also known to be required for splicing and which are present in spliceosomal complexes. RNA8 is also involved in an ATP-dependent association with two other small nuclear RNAs, snR14 and snR6.

Maturation of antioxidant enzymes in rat small intestine: lack of glucocorticoid stimulation.

We report in detail the ontogeny and the response of antioxidant enzymes to glucocorticoids in the rat small intestine. Pregnant rats in the treatment group received four injections of dexamethasone starting on days 18, 19, or 20 of gestation; fetuses were killed 2 days later. Control rats were injected with 0.

Comparison of measurement methods for capillary basement membrane thickness. Collapsed-ellipse technique.

Both the grid method of Siperstein et al. (tSIP) and the minimum-points method of Williamson et al. (tWIL) for measurement of capillary basement membrane thickness are inaccurate for assessing mean true membrane thickness of a give section (tTRUE) for various reasons, including errors in selectivity, sensitivity, and geometry.

Comparative study of rat sciatic nerve microepineurial anastomoses made with carbon dioxide laser and suture techniques: Part 2. A morphometric analysis of myelinated nerve fibers.

Sciatic nerves of rats were severed with steel scalpel blades and subsequently anastomosed with epineurial sutures and laser-aided techniques. Morphometric analysis of myelinated nerve fibers proximal and distal to the anastomosed region revealed that the laser had no deleterious effects on the degree of retrograde axonal degeneration or regeneration potential as compared to the traditional suture technique. Although no significant difference in myelinated nerve fiber population was evident between the two methods, future experimentation with various laser parameters might lead to more effective use of lasers in nerve repair.

Identification of the RNA2 protein of Saccharomyces cerevisiae.

The rna2-1 mutant of Saccharomyces cerevisiae has a conditional lethal phenotype, accumulating high molecular weight RNAs of intron-containing nuclear genes at 36 degrees C. The cloned RNA2 gene suppresses this phenotype and the RNA2 gene product has been implicated in RNA splicing. Rabbit antisera have been raised against an N-terminal synthetic peptide taken from the RNA2 gene DNA sequence data, and against a beta-galactosidase/RNA2 gene fusion protein.

Comparative study of microepineurial anastomoses with the use of CO2 laser and suture techniques in rat sciatic nerves: Part 1. Surgical technique, nerve action potentials, and morphological studies.

The possibility of utilizing the CO2 laser for neural anastomoses was investigated in a rat sciatic nerve model. One nerve in each animal was acutely divided and anastomosed using 10-0 nylon epineurial sutures, while the opposite side was joined by "welding" the opposed nerve ends together with CO2 laser pulses. The surgical incisions were reexplored 60 days postoperatively, action potentials were recorded across the anastomoses, and the nerves were removed for light and electron microscopy.

Cloning of the RNA2 gene of Saccharomyces cerevisiae.

The RNA2 gene of Saccharomyces cerevisiae, which has been implicated in splicing the transcripts of nuclear protein coding genes, has been cloned by complementation of the temperature-sensitive growth defect of an rna2-1 mutant strain. The cloned sequence also suppresses the accumulation of unspliced precursor transcripts of the actin gene in an rna2-1 mutant. The gene has been localised to a 3.

Comparative study of neuroma formation in the rat sciatic nerve after CO2 laser and scalpel neurectomy.

Recent reports have suggested that peripheral neurectomy with the CO2 laser may be effective in preventing subsequent neuroma formation. To study this question further, we performed bilateral sciatic nerve sections in 31 rats using a steel scalpel on one nerve and a CO2 laser on the opposite side. The animals were killed 30 days after neurectomy and specimens were removed for gross observation, light microscopy, and electron microscopy.

Aberrant splicing of Drosophila alcohol dehydrogenase transcripts in Saccharomyces cerevisiae.

We have investigated the ability of transcripts of the Drosophila melanogaster alcohol dehydrogenase gene to be spliced in Saccharomyces cerevisiae. The alcohol dehydrogenase gene was cloned in S. cerevisiae on a 2 micron DNA-based vector and a hybrid yeast actin-Drosophila alcohol dehydrogenase gene was constructed to demonstrate that transcripts encoded on a 2 micron plasmid could be accurately and efficiently spliced.

Abnormal expression of chromosomal rabbit beta-globin gene in Saccharomyces cerevisiae.

A 5.1 kilobase-pair segment of rabbit chromosomal beta-globin DNA was joined to pJDB219, a plasmid consisting of pMB9, the 2-mu yeast plasmid and the yeast leu-2 gene. Saccharomyces cerevisiae transformed with the globin DNA-containing hybrid produced beta-globin-specific RNA.

Transformation of yeast by a replicating hybrid plasmid.

Chimaeric plasmids have been constructed containing a yeast plasmid and fragments of yeast nuclear DNA linked to pMB9, a derivative of the ColEl plasmid from E. coli. Two plasmids were isolated which complement leuB mutations in E.

Regulation of synthesis of benzyl alcohol dehydrogenase in Acinetobacter calcoaceticus NCIB8250.

Specific activity of benzyl alcohol dehydrogenase in carbon-limited continuous cultures was at a maximum at a specific growth rate of 0.2 h-1, but fell off at lower and higher growth rates. The specific activity in nitrogen-limited cultures was always lower and was inversely proportional to growth rate.

A map of the restriction targets in yeast 2 micron plasmid DNA cloned on bacteriophage lambda.

The 2 micron circular DNA from S. cerevisiae has been cloned on bacteriophage lambda. The two forms of circular DNA which exist in equilibrium due to recombination between inverted repeat sequences were separated as stable clones, and a map of targets for restriction endonucleases EcoRI, HindIII and HpaI was constructed.

Regulation of growth of Acinetobacter calcoaceticus NCIB8250 on benzyl alcohol in batch culture.

Formation of benzoate and catechol during oxidation of benzyl alcohol by washed suspensions of Acinetobacter calcoaceticus NCIB8250 confirmed earlier results indicating that this organism metabolizes benzyl alcohol via benzaldehyde, benzoate, and the 3-oxoadipate pathway. There was no evidence for feedback inhibition of benzyl alcohol dehydrogenase or benzaldehyde dehydrogenase II. Examination of growth curves and patterns of substrate utilization, as well as measurement of enzyme activities, showed that benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase II are repressed when A.

The construction in vitro of transducing derivatives of phage lambda.

Methods are described for the construction of plaque-forming, transducing derivatives of phage lambda, using appropirate receptor genomes and fragments of DNA generated by the restriction enzymes endo R.EcoRI and endo R.HindIII.

Transendothelial vesicular transport of protein following compression injury to the spinal cord.

Routes of vascular leakage resulting in trauma-induced edema have not been clarified. To explore the problem we followed the fate of intravascular horseradish peroxidase (HRP) after compression injury to the thoracic cord (cats). At 90 seconds and 15 minutes, HRP was confined to the gray matter, occupying perivascular spaces, unexpanded extracellular channels, and cytoplasmic compartments of injured cells.

Regulation of growth of Acinetobacter calcoaceticus NCIB8250 on L-mandelate in batch culture.

Batch culture of Acinetobacter calcoaceticus in L-mandelate- or phenylglyoxylate-salts medium showed an unusual non-exponential pattern unless the inoculum had been grown on benzyl alcohol. There were transient accumulations of benzaldehyde and benzyl alcohol caused by the limitation of L-mandelate oxidation by low activities of benzaldehyde dehydrogenase and the diversion of reducing power to the formation of benzyl alcohol. In vivo enzymic activities were estimated from patterns of substrate utilization in batch cultures containing pairs of substrates.