The structure and evolution of the spider monkey delta-globin gene

We have isolated the delta-globin gene of the New-World spider monkey, Ateles geoffroyi, and compared its nucleotide sequence with those of other primate delta- and beta-globin genes. Among primate delta-globin genes, the rate of nonsynonymous substitutions is much less than the rate of synonymous substitutions. This suggests that primate delta- globin genes may remain under evolutionary conservation, perhaps because hemoglobin A2 has an as yet unknown physiological importance.      

Biochemical pathways in prokaryotes can be traced backward through evolutionary time

For the first time, a credible prokaryotic phylogenetic tree is being assembled by Woese and others using quantitative sequence analysis of oligonucleotides in the highly conservative rRNA. This provides an evolutionary scale against which the evolutionary steps that led to the arrangement and regulation of contemporary biochemical pathways can be measured. This paper presents an emerging evolutionary picture of aromatic amino acid biosynthesis within a large superfamily assemblage of prokaryotes that is sufficiently developed to illustrate a new perspective that will be applicable to many other biochemical pathways.      

Development of the cytosolic defence system against microsomal lipid peroxidation in rat liver

Ascorbate-induced lipid peroxidation in rat liver microsomes reaches the adult level in 2-3 days. NADPH-induced peroxidation develops more gradually, in parallel with the activity of NADPH-cytochrome P-450 reductase, attaining adult levels by 10-12 days. The glutathione-dependent cytosolic enzyme activity which inhibits peroxidation is inhibited by bromosulphophthalein. The development of this system lags behind the development of microsomal lipid peroxidation between the ages of 2 and 20 days, allowing peroxidation to proceed.     

A calcium antagonist drug binding site in skeletal muscle sarcoplasmic reticulum: Evidence for a calcium channel

The sarcoplasmic reticulum (S.R.) of rabbit skeletal muscle has been found to contain a single, high affinity binding site for the Ca antagonist drug [³H] -nitrendipine. Two subfractions of the reticulum were studied, the heavy (HSR) and light (LSR) preparations, which exhibited similar nitrendipine equilibrium dissociation constants (K_D) of 1nM. Crude cardiac and brain membranes assayed under the same conditions exhibited K_D values of 0.2–0.3nM. The concentration of binding sites per mg. protein (B_max) in HSR was found to be very high, namely 6.7 picomoles/mg, some four times greater than that of LSR. [³H] -nitrendipine binding to HSR was reversible and inhibited by the Ca antagonists flunarizine and verapamil, and by the intracellular Ca release antagonist TMB-8 (8-diethylamino-octyl 3,4,5- trimethylbenzoate hydrochloride). However, unlabelled nitrendipine at 2 × 10^?5M had no effect on contraction of isolated electrically stimulated rabbit lumbrical or rat diaphragm muscles, nor did it affect the neuromuscular junction as studied in rat phrenic nerve-diaphragm preparations. Also, little effect of 2 × 10^?5M nitrendipine was seen on net ⁴⁵Ca uptake by HSR. These results suggest that [³H] -nitrendipine binding to skeletal muscle S.R. resembles that of brain membranes, which also contain a high affinity binding site for [³H] -nitrendipine and which similarly are pharmacologically insensitive to this dihydropyridine type of Ca channel blocking agent. Since HSR is also enriched in calsequestrin and terminal cysternae from which Ca is released in vivo, it seems likely that the [³H]- nitrendipine binding sites in S.R. are associated with Ca channels in the S.R.     

Biological control of Dutch elm disease: Bacillus thuringiensis as a potential control agent for Scolytus scolytus and S. multistriatus

J assim , H.K., F oster , H.A. & F airhurst , C.P. 1990. Biological control of Dutch elm disease: Bacillus thuringiensis as a potential control agent for Scolytus scolytus and S. multistriatus. Journal of Applied Bacteriology 69 , 563–568.
The effects of exposing fifth instar larvae of Scolytus scolytus and S. multistriatus to spore suspensions of Bacillus spp. were investigated. Bacillus thuringiensis ser 3a, 3b increased the mortality of larvae cultured on an artificial medium from approximately 20% in control cultures to over 80% in cultures exposed to the bacteria. The mortality was dose-dependent for S. multistriatus and the approximate LC₅₀ value was 2.2 times 10³ spores/ml. Different serotypes of B. thuringiensis caused different levels of mortality: H6 produced the highest mortality and H1 the lowest. Bacillus alvei and B. cereus were also pathogenic but B. megaterium was not. The results are discussed in relation to the mechanism of pathogenicity and the potential for the use of B. thuringiensis for the control of the vectors of Dutch elm disease.     

The evolutionary history of the amylase multigene family in Drosophila pseudoobscura

In Drosophila pseudoobscura, the amylase (Amy) multigene family is contained within a series of inversions, or gene arrangements, on the third chromosome. The Standard (ST), Santa Cruz (SC), and Tree Line (TL) inversions are central to the phylogeny of arrangements, and have clusters of other arrangements derived from them. The gene arrangements belonging to each of these three clusters have a characteristic number of Amy genes, ranging from three in ST to two in SC to one in TL. This distribution pattern can reflect a history of either duplications or deletions, although the data available in the past did not permit a decision between these alternatives. We provide unambiguous evidence that three Amy genes were present before the divergence of the ST, SC, and TL arrangements. Thus, the current status of the Amy multigene family is the result of deletions in the TL and SC arrangements, which created three new pseudogenes: TL Amy2-psi, TL Amy3-psi, and SC Amy3- psi. Analysis of pseudogene sequences revealed that, in the SC and ST arrangements, pseudogene evolution has been retarded, most likely due to the homogenization effect of gene conversion. Finally, by determining the original copy number, we have reconstructed the evolutionary history of the Amy multigene family and linked it with the evolution of the central gene arrangements.      

USE OF SENSORY EVALUATION FOR MEASURING DEODORIZING EFFECTS OF AN AIR CONDITIONER

The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R² values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.     

Naloxone enhancement of acetic acid-induced writhing in rats

Long-lasting visceral pain was produced in rats by the intraperitoneal injection of dilute acetic acid, and the response to this stimulus measured by observing the number of writhes over a subsequent 50 min. period. Prior treatment of the animals with naloxone or saline showed that naloxone increased the frequency of writhing. The enhancement by naloxone of the response to this nociceptive stimulus suggests that the binding of an endogenous opioid to the opiate receptors increases during prolonged nociceptive stimulation.     

Ethylene and IAA transport in potato

Although elongation growth is reduced by ethylene, swelling responses do not occur. Ethylene reduces neither transport nor metabolism of applied IAA in either mesocotyl or coleoptile. We propose that maintenance of high auxin levels within these tissues sustains polar transport and contributes to the relative insensitivity of maize to applied ethylene.