Genetic coadaptation in the chromosomal polymorphism of Drosophila subobscura II. Changes of gametic disequilibrium in experimental populations

Experimental populations were examined for temporal changes of gametic disequilibria between allozyme loci (Lap and Pept-1) and gene arrangements of the O chromosome of Drosophila subobscura (O _st and O ₃₊₄₊₇) under several environmental conditions. In the foundation of the experimental populations a genetic perturbation was carried out in order to test the relevance of the current hypotheses used to explain the allozyme-inversion associations observed in natural populations. Differential changes of gametic disequilibria were detected over generations under the different environmental conditions. Mere mechanical or stochastic factors cannot explain the results and natural selection is probably the major agent generating the detected gametic associations. The observations are interpreted as a proof of coadaptation of D. subobscura inversions.     

Locations and stability of Agrobacterium-mediated T-DNA insertions in the Lycopersicon genome

Summary The genomic distribution and genetic behavior of DNA sequences introduced into the tomato genome by Agrobacterium tumefaciens were investigated in the backcross progeny of 10 transformed Lycopersicon esculentum x L. pennellii hybrids. All transformants were found to represent single locus insertions based on the co-segregation of restriction fragments corresponding to the T-DNA left and right border sequences in the backcross progeny. Isozyme and restriction fragment length polymorphism (RFLP) markers were used to test linkage relationships of the insertion in each backcross family. The T-DNA inserts in 9 of the 10 transformants were mapped in relation to one or more of these markers, and each mapped to a different chromosomal location. Because only one insertion did not show linkage with the markers employed, it must be located somewhere other than the genomic regions covered by the markers assayed. We conclude that Agrobacterium-mediated insertion in the Lycopersicon genome appears to be random at the chromosomal level. No discrepancies were found between the T-DNA genotype and the nopaline phenotype in the 322 backcross progeny of the nopaline positive transformants. Backcross progeny of two nopaline negative transformants showed incomplete correspondence between the T-DNA genotype and the kanamycin resistance phenotype. No alteration of T-DNA was observed in progeny showing a discrepancy between T-DNA and kanamycin resistance. However, two kanamycin resistant progeny plants of one of these two transformants possessed altered T-DNA restriction patterns, indicating genetic instability of the T-DNA in this transformant.Journal article no. 1223 of the New Mexico Agricultural Experiment Station     

Effect of topically applied steroidal and nonsteroidal anti-inflammatory agents on skin repair and regeneration

We studied the effects of topically applied steroidal and nonsteroidal anti-inflammatory agents on dermal and epidermal wound healing. Superficial wounds (0.3 mm deep) on the skin of domestic pigs were treated daily with either 0.1% triamcinolone acetonide (TA), 1% hydrocortisone (HC), 1% nandrolone decanoate (ND), 1% ND + 0.1% TA, 10 mg ibuprofen, 10 mg meclofenamate sodium, 3 mg indomethacin, vehicle (USP petrolatum or 70% ethanol), or control (untreated). Wounds were excised on days 2-7 after wounding and the epidermis was separated from the dermis. The dermis was assayed for collagen biosynthesis and the epidermis was evaluated for reepithelialization. A significant decrease (P less than 0.01) in relative collagen synthesis was observed in the wounded dermis in both HC- and TA-treated groups on day 3 after wounding, but there were no significant differences on days 4-7. Depressed collagen and noncollagenous protein production was also noted in vehicle-treated wounds on day 3. Topical application of ND did not affect collagen synthesis, but when combined with TA it eliminated the inhibitory effect observed as a result of TA alone. Topical ND accelerated wound reepithelialization by 12.5% compared with vehicle and by 26% compared with untreated controls. TA delayed epidermal resurfacing by 22%, but when combined with ND (ND + TA) the rate of reepithelialization was similar to vehicle-treated wounds. HC enhanced resurfacing when compared with untreated wounds but did not differ markedly from its vehicle. The nonsteroidal anti-inflammatory drugs when topically applied markedly reduced inflammation (erythema, heat, and edema) but did not influence the healing process.     

Insulin regulation of insulin-like growth factor action in rat hepatoma cells

We have reported previously that insulin causes a complete but reversible desensitization to insulin action in rat hepatoma HTC cells in tissue culture, and that this insulin resistance is mediated by postbinding mechanisms rather than receptor down-regulation (Heaton, J. H., and Gelehrter, T. D. (1981) J. Biol. Chem. 256, 12257-12262). We report here that insulin causes a similar desensitization to the induction of tyrosine aminotransferase by the insulin-like growth factors IGF-I and IGF-II isolated from human plasma, and by multiplication-stimulating activity, the rat homologue of IGF-II. The results of both competition-binding studies and affinity cross-linking experiments indicate that insulin-like growth factors (IGFs) bind primarily to IGF receptors rather than to insulin receptors. The low concentrations at which these factors induce transaminase is consistent with their acting primarily via IGF receptors. This is confirmed by experiments utilizing anti-insulin receptor antibody which both inhibits 125I-insulin binding and shifts the concentration dependence of insulin induction of tyrosine aminotransferase to the right. This same immunoglobulin does not inhibit 125I-multiplication-stimulating activity binding and only minimally inhibits 125I-IGF-I binding. Anti-insulin receptor antibody also does not significantly shift the concentration dependence for the IGFs, suggesting that IGFs induce transaminase by acting via IGF receptors. Although insulin down regulates insulin receptors, it does not decrease IGF-I or IGF-II binding. We conclude that insulin causes desensitization of HTC cells to IGFs by affecting a postbinding step in IGF action, which may be common to the actions of both insulin and insulin-like growth factors.     

Reaction of ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate with acetylenic esters

Ethyl 2-amino-4,6-O-benzylidene-2-deoxy-d-gluconate adds to acetylenic esters to give sugar enaminones. The following acetylene derivatives have been employed: methyl propiolate, ethyl phenylpropiolate, and dimethyl acetylenedicarboxylate (6). With compound 6, the reaction leads to a mixture of the expected enaminone and the isomeric oxazolidine derivative. The structures and configurations of the new compounds were studied by spectroscopic and chemical methods.     

Characterization, Localization, and Biosynthesis of an Interstitial Retinol-Binding Glycoprotein in the Human Eye

Abstract: Human eyes contain an M_r 135K retinol-binding protein that is analogous to interstitial retinol-binding protein (IRBP) in the subretinal space of bovine eyes. It is a glycoprotein, because it binds ¹²⁵I-concanavalin A, ¹²⁵I-wheat germ agglutinin and ¹²⁵I- Lens culinaris hemagglutinin. It does not bind Ricinus communis agglutinin I. After desialation, it binds Ricinus communis agglutinin I, but loses its capacity to bind wheat germ agglutinin. These observations, coupled with the known specificities of these lectins, suggest that at least one of the oligosaccharide chains is a sialated, biantennary complex type containing fucose. Both by direct analysis of dissected ocular tissues and by immunocytochemistry it was shown that human interstitial retinol binding protein is an extracellular protein that is confined predominantly to the subretinal space. Monkey retinas incubated in vitro in medium containing [³H]leucine were shown to synthesize and secrete this protein into the medium, a conclusion that was confirmed by immunoprecipitation with an immunoglobulin fraction prepared from rabbit antibovine IRBP serum. Virtually no other labeled proteins were detectable in the medium. It is concluded that interstitial retinol-binding protein meets many of the requirements for a putative transport protein implicated in the transfer of retinol between the pigment epithelium and retina during the visual cycle, and that the neural retina may play an important role in regulating its amount in the subretinal space.     

A comparison of the effect of three fungicides on growth and roridin E production by Myrothecium roridum

Three fungicides, chlorothalonil, dichloran and mancozeb were studied to determine the effects on growth and production of roridin E by Myrothecium roridum in vitro. With increasing concentrations of fungicides, both growth and production of roridin E were inhibited. Of the three fungicides, chlorothalonil was much more effective in the inhibition of growth and production of roridin E, than dichloran and mancozeb.     

Study of a madurella grisea strain isolated from a foot mycetoma

Madurella grisea has been isolated from a madura foot with black grains. The fungi classification was made based on the macro and micro-morphology characteristics of the culture. Difficulties with the interpretation of biochemistry tests were analized. The study is completed with trials of in vitro sensibility for different antifungic agents.     

Spontaneous binding ofYersinia enterocolitica to murine leukocytes

Twelve strains ofYersinia enterocolitica were examined for their ability to bind spontaneously to murine leukocytes. Each of eight HeLa cell invasive strains exhibited nonselective binding to peritoneal leukocytes, lymph node leukocytes, and thymocytes, whereas four noninvasive strains lacked binding properties. Like the HeLa cell invasion, the binding ofY. enterocolitica to leukocytes was much less efficient for bacteria grown at 37°C than for bacteria grown at 22°C. The binding properties were not influenced by the virulence plasmid that codes for Vwa⁺ phenotype. This leukocyte binding test is proposed as a simple assay for invasive properties ofY. enterocolitica.