Phototropic stimulation does not induce unequal distribution of indole-3-acetic acid in maize coleoptiles

Distribution of endogenous diffusible auxin into agar blocks from phototropically stimulated maize coleoptile tips was studied using a bioassay and a physicochemical assay, to clarify whether phototropism in maize coleoptiles involves a lateral gradient in the amount of auxin. At 50 min after the onset of phototropic stimulation, when the phototropic response was still developing, direct assay of the blocks with the Avena curvature test showed that the auxin activity in the blocks from the shaded half-tips was twice that of the lighted side, at both the first and second positive phototropic curvatures. However, physicochemical determination following purification showed that the amount of indole-3-acetic acid (IAA) was evenly distributed in the blocks from lighted and shaded coleoptile half-tips at both the first and second positive phototropic curvatures. The even distribution of the IAA was also confirmed with the Avena curvature test following purification by HPLC. These results indicate that phototropism in maize coleoptiles is not caused by a lateral gradient of IAA itself and thus cannot be described by the Cholodny-Went theory. Furthermore, the lower auxin activity in the blocks from the lighted half-tips suggests the presence of inhibitor(s) interfering with the action of auxin and their significant diffusion from unilaterally illuminated coleoptile tips.     

1H NMR studies of deuterated ribonuclease HI selectively labeled with protonated amino acids

Summary Two-dimensional (2D)¹H NMR experiments using deuterium labeling have been carried out to investigate the solution structure of ribonuclease HI (RNase HI) fromEscherichia coli (E. coli), which consists of 155 amino acids. To simplify the¹H NMR spectra, two fully deuterated enzymes bearing several prototed amino acids were prepared from an RNase HI overproducing strain ofE. coli grown in an almost fully deuterated medium. One enzyme was selectively labeled by protonated His, He. Val. and Leu. The other was labeled by only protonated His and Ile. The 2D¹H NMR spectra of these deuterated R Nase H1 proteins, selectively labeled with protonated amino acids, were much more simple than those of the normally protonated enzyme. The simplified spectra allowed unambiguous assignments of the resonance peaks and connectivities in COSY and NOESY for the side-chain protons. The spin-lattice relaxation times of the side-chain protons of the buried His residue of the deuterated enzyme became remarkably longer than that of the protonated enzyme. In contrast, the relaxation times of the side-chain protons of exposed His residues remained essentially unchanged.     

Temporal behavioral variation and division of labor among workers in the primitively eusocial wasp,Polistes jadwigae Dalla Torre

The behavior of workers on 2 nests of the Japanese paper wasp,Polistes jadwigae, was recorded on video tape. Young workers performed pulp collection more frequently than middle-aged and old workers, while foraging of flesh (prey) was done mainly by middle-aged workers. Of the 26 behavioral categories, 7 showed negative, 2 concave, and 1 convex relationship to the workers age. Using behavioral profiles, workers could be classified into 3 age groups: 1) young workers (younger than 10 days old, active intranidal workers), 2) middle-aged workers (11–25 days old, extranidal workers) and 3) old workers (older than 26 days old, ‘idlers’). Idlers engaged in foraging and larval feeding significantly less frequency than the young and middle-aged workers, but they performed alerting toward many alien objects. Task specialization among workers irrespective of age polyethism was also suggested.     

Altered localization of antigen recognized by proteinuriainducing monoclonal antibody in experimental nephrosis

Change in the localization of the antigen recognized by the proteinuria-inducing monoclonal antibody (MA) 5-1-6 in experimental nephrosis was studied by indirect and biotin-avidin immunofluorescence, and immunoperoxidase at light and electron microscopical levels. The proteinuric state was induced by the administration of the aminonucleoside of puromycin (PAN) or adriamycin. The antigen decreased in quantity and/or its distribution changed with an increase in the amount of protein excreted in both experimental models. Recovery from the alterations observed during the development and proteinuria appeared to occur when PAN-induced proteinuria subsided. This antigenic molecule may thus be essential for maintaining the normal permselectivity of glomerular capillary walls.     

Eimeria tenella, E. necatrix, E. acervulina, E. maxima, and E. brunetti: potent anticoccidial activity of an uridine analog, 1-(beta-D-ribofuranosyl)-2(1H)-pyrazinone 4-oxide

The anticoccidial activity of an uridine analog, 1-(beta-D-ribofuranosyl)-2(1H)-pyrazinone 4-oxide (emimycin riboside), against five species of chicken Eimeria was tested individually in battery experiments. With 16 ppm of the compound in feed, marked anticoccidial activity was obtained against Eimeria tenella, E. necatrix, E. acervulina, E. maxima, and E. brunetti. The last named species was more drug-sensitive than the others--dietary levels of at least 8 ppm of the drug exhibited good protection and eliminated practically all clinical signs. The battery tests with delayed and restricted medications showed that emimycin riboside affected the development of parasites in first and second generation schizogony of the life cycle of E. tenella.     

Circadian rhythms in the activities of brain and liver aldehyde dehydrogenase isozymes in mice

Circadian variations in the activities of aldehyde dehydrogenase (ALDH) isozymes in the subcellular fractions of the brain and liver were investigated in male and female mice of C57BL/6J strain. The rhythms in high Km-ALDH activities of brain and liver mitochondrial fractions which existed in ordinary light-dark cycle were not observed in animals maintained in the continuous darkness for two weeks. The rhythms in high Km-ALDH activities of hepatic soluble and microsomal fractions existed in both ordinary cycle and total darkness but the rhythmic phases were different. In the low Km-ALDH activity of hepatic mitochondrial fraction, the circadian rhythm was similar in two lighting conditions. There was sex difference in the existence of the circadian rhythm. It seems that the ALDH activity of mice is influenced by light-dark cycle and sex hormones.     

Effect of temperature and cell density on cellular protein content in temperature-sensitive mutants of rat 3Y1 diploid fibroblasts

Summary We examined cellular protein content in four temperature-sensitive (ts) mutants of rat 3Y1 fibroblasts (3Y1tsD123, 3Y1tsF121, 3Y1tsG125, and 3Y1tsH203) under various conditions of culture that affect cell proliferation. When proliferation of the ts mutants was inhibited at a nonpermissive temperature (39.8°C) in the G₁ phase, prominent accumulation of cellular protein occurred in three mutants (3Y1tsF121, 3Y1tsG125, and 3Y1tsH203) but not in 3Y1tsD123. The over-accumulation of protein at 39.8°C in the former three mutants was inhibited at high cell densities. At low cell densities there was an upper limit in the protein accumulation at 39.8°C. When the three mutants, proliferation-arrested at high cell densities at 33.8°C, were replated sparsely in fresh medium and shifted to 39.8°C, proliferation was completely inhibited whereas over-accumulation of protein occurred. These results indicating dissociation of protein accumulation and cell proliferation suggest that the two events are regulated by different mechanisms. This work was supported in part by a Grant-in-Aid for Encouragement of Young Scientists (1984) to K. Y. from the Ministry of Education, Science, and Culture, Japan.     

Three-year survey of the epidemiology of rotavirus, enteric adenovirus, and some small spherical viruses including "Osaka-agent" associated with infantile diarrhea

Studies were made by electron microscopy (EM) on the viruses associated with diarrhea of outpatients at a pediatric clinic in Osaka Prefecture during the three year period from 1980 through 1982. The viruses detected by EM by negative staining with phosphotungstic acid (PTA) were classified morphologically into 6 groups: rotavirus, adenovirus and four kinds of small spherical viruses, calicivirus, astrovirus, picornavirus/parvovirus (P/P)-like agent and Osaka-agent. Osaka-agent seems to be a newly identified small virus. It is 35-40 nm in diameter with a fringe of spike-like structures on its surface. Viruses were detected in 181 of the 395 cases of diarrhea (45.8%). Rotavirus was detected in 122 (30.9%) of the total cases and in 67.4% of the virus-positive cases, while other viruses were detected in 15% of the total cases; adenovirus in 23 (6%) and small agents in 36 (9%). Rotavirus infection showed a distinctive seasonal variation, being mainly restricted to cooler months, but infections with other viruses did not show any seasonal variation. The age distribution of patients suggested that infants of 0 to 2 years old are very susceptible to all viruses. Attempts to cultivate these viruses in vitro were successful with only two isolates of adenovirus type 5.     

Genotoxicity of carcinogenic N-nitrosopropylamine derivatives in the hepatocyte primary culture/DNA-repair test

The genotoxicity of N-nitrosodipropylamine, 8 of its oxidized derivatives and N-nitroso-2,6-dimethylmorpholine was examined in the hepatocyte primary culture (HPC)/DNA repair test. Nine N-nitrosamines which are known to be carcinogenic and mutagenic were clearly positive in the HPC/DNA-repair test. N-Nitroso(2,3-dihydroxypropyl) (2-hydroxypropyl)amine did not elicit DNA repair, but showed a borderline mutagenic response in the Salmonella/microsome test. Thus, the HPC/DNA-repair test displays a comparable capacity to the bacterial mutagenesis test for detecting the genotoxic effects of this class of carcinogens.     

Reduction of Aluminum Toxicity by Addition of a Conditioned Medium from Aluminum-Tolerant Cells of Carrot

The toxic effect of aluminum (Al) on the growth of Carrot cells(SO-l) decreased to a greater degree with addition of a mediumconditioned by Al-tolerant carrot cells (TA-l) than with a mediumconditioned by SO-l cells. The toxic effect of Al was reducedgreatly by adding an acidic fraction of the conditioned media,but little or not at all by a neutral or basic fraction. Offour organic acids detected in the acidic fraction, the majorone was citric acid which was present in a much greater amountin the conditioned medium of TA-l cells than in that of SO-lcells. The toxic effect of Al was reduced by adding citric or malicacid instead of the conditioned medium, but not by succinicor fumaric acid. Chelating abilities of the organic acids wereevaluated by shifts in their titration curves, and were foundto be closely correlated with the detoxification effects. Thus,the Al tolerance of TA-l cells may in fact be due to the chelatingeffect of citric acid which is abundantly released into themedium by the Al-tolerant carrot cells. (Received July 9, 1984; Accepted November 22, 1984)