Effect of LSD on mitotic and meiotic plant chromosomes

LSD was found to induce chromosomal aberrations in root tip cells of Allium cepa, Hordeum vulgare and Secale cereale. Aberrations occurred in the form of chromatid and isochromatid breaks with most of these breaks failing to rejoin. The distribution of chromosome breaks was not uniform over the length of chromosomes, and a majority of the breaks were localized at the centromeric regions. For a given dose of LSD (30 g/ml), onion appeared to be more susceptible than barley or rye. The diploid and tetraploid rye used in the study showed no appreciable difference in sensitivity to LSD treatment. — A preliminary study on meiotic chromosomes in LSD-treated diploid rye revealed the presence of univalents, chromosome breaks and fragments, suggesting that LSD can induce meiotic abnormalities in plant material.Contribution from the Department of Agronomy, University of Kentucky. The investigation reported in this paper (73-3-75) is in connection with a project of the Kentucky Agricultural Experiment Station and is published with the approval of the Director.     

Importance of carbon dioxide in the isolation of pneumococci

Austrian, Robert (The University of Pennsylvania School of Medicine, Philadelphia), and Patricia Collins. Importance of carbon dioxide in the isolation of pneumococci. J. Bacteriol. 92:1281-1284. 1966.-Of the strains of pneumococci isolated from man, 8% manifest a requirement for CO(2) if detectable growth is to occur on the surface of solid media. The pneumococci most frequently manifesting this requirement are types I, III, XVI, XXVIII, and XXXIII. These strains will grow in the presence or absence of oxygen provided the atmosphere in which they are incubated contains CO(2). Review of published data provides no unequivocal evidence for the existence of anaerobic pneumococci.     

Preparation of microtubules from rat liver and testis: cytoplasmic dynein is a major microtubule associated protein

A microtubule associated protein from brain tissue (MAP 1C), has been found to possess many properties in common with ciliary and flagellar dyneins (Paschal et al.:J. Cell Biol. 105:1273-1282, 1987). However, this protein, now designated as cytoplasmic dynein, exhibited several properties which distinguish it from axonemal forms of the enzyme. We have investigated these characteristics further in a study of cytoplasmic dyneins from non-neuronal tissues. Rat liver and testis in particular were found to contain high levels of cytoplasmic dynein. The yield of dynein from testis was over 70 micrograms/g of tissue, making this the best source of cytoplasmic dynein of all tissues so far examined. The characterization of dynein from these sources has confirmed and extended our previous observations concerning the unique properties of cytoplasmic dynein. Activation of liver and testis dynein occurred at low (less than 1 mg/ml) tubulin concentration. Polypeptides identified as subunits of brain cytoplasmic dynein (74, 59, 57, 55, and 53 kDa) were present in liver and testis preparations. In addition, polypeptides at 150 and 45 kDa were found to copurify with the non-neuronal dyneins. The liver and testis enzyme hydrolyzed pyrimidine nucleotides at rates up to 12.5 times faster than ATP, though the relative affinity of cytoplasmic dynein for CTP was much lower (Km = 1.0 mM) than that for ATP. The properties of the testis enzyme were consistent with its identification as a cytoplasmic dynein rather than a sperm axonemal precursor. These data indicate that cytoplasmic dyneins may be widespread in distribution and that they share certain biochemical properties unique from those of axonemal dyneins. These characteristics are consistent with the proposal that cytoplasmic dynein plays a universal role in retrograde organelle motility.     

Expression of the Ganglioside GD3 in Human Meningiomas Is Associated with Monosomy of Chromosome 22

The ganglioside composition of 59 meningiomas has been compared with a molecular genetic analysis of chromosome 22 in the same specimens. Major gangliosides were GM3 (II3NeuAc-LacCer) and/or GD3 [II3(NeuAc)2-LacCer]. In specimens with no or partial deletions of chromosome 22, the GM3 ganglioside predominated, and the mean value for GM3, 61% of total sialic acid, was around four times higher than that for GD3. A loss of chromosome 22, found in 56% of the specimens, was shown to be associated with an increase in the proportion of ganglioside GD3, with the ratio between mean values of GM3 and GD3 being approximately 1:1. Logistic regression revealed that the probability of predicting monosomy of chromosome 22 by the GD3 proportion was 66%.     

Plant regeneration of wildGlycine species from suspension culture-derived protoplasts

Protoplasts isolated from four-week old cell suspension cultures ofGlycine canescens F. J. Herm andG. clandestina Wendl. were cultured in 8P or modified 8P to a multicellular stage. Colonies of 0.5 to 1.0 mm diameter were transferred to solid media for callus growth and regeneration. Callus consisted of friable masses with compact green nodular areas. Organogenesis of both species occurred primarily from the green nodular areas. Shoot buds ofG. clandestina did not mature, but shoots ofG. canescens proliferated on MS medium, with B5 vitamins, 0.33 mgL^–1 each BA, KN, ZN, and 0.15 mgL^–1 NAA. Shoots failed to root after multiple subcultures on four different rooting media.In vitro grafting ofG. canescens scions ontoG. max root stocks allowed plants to be transferred to soil. An overall protoplast division efficiency of 48% was achieved with moderately efficient shoot regeneration inG. canescens. Division efficiencies forG. clandestina were lower (11%). Refinements of this protocol should result in high efficiencies of regeneration which would allowin vitro manipulations of these wild soybean relatives at the single cell level and would make the derivation of somatic hybrid plants possible within the genusGlycine.Abbreviations BA 6-Benzyladenine - KN kinetin - ZN Zeatin - NAA Napthaleneacetic acid - 2,4-D 2–4-dichlorophenoxyacetic acid - PIC Picloram - CH casein hydrolysate - Gln glutamine - Met methionine - MES 2[N-morpholine] ethanesulfonic acid     

Purification of L-[3H]nicotine eliminates low affinity binding

Some studies of L-[3H]nicotine binding to rodent and human brain tissue have detected two binding sites as evidenced by nonlinear Scatchard plots. Evidence presented here indicates that the low affinity binding site is not stereospecific, is not inhibited by low concentrations of cholinergic agonists and is probably due to breakdown products of nicotine since purification of the L-[3H]nicotine eliminates the low affinity site.