Biosynthesis of gallic and ellagic acids with14C-labeled compounds inAcer andRhus leaves

The biosynthetic pathway for gallic and ellagic acids in young, mature and autumn leaves ofAcer buergerianum andRhus succedanea was examined by tracer experiments, and also by isotope competition, withd-shikimic acid-¹⁴C,l-phenylalanine-U-¹⁴C,l-phenyllactic acid-U-¹⁴C, gallic acid-G-¹⁴C and their unlabeled compounds. In young leaves of both plants, the incorporation rate of labeled shikimic acid into gallic acid was significantly higher than that of labeled phenylalanine, whereas in the mature and autumn leaves the latter was a good precursor rather than the former for the gallic acid biosynthesis. Therefore, two pathways for gallic acid formation, through β-oxidation of phenylpropanoid and through dehydrogenation of shikimic acid, could be operating inAcer andRhus leaves, and the preferential pathway is altered by leaf age. In both plants, the incorporation rate of labeled phenyllactic acid during a 24 hr metabolic period was almost the same as that of labeled phenylalanine. The incorporation ofd-skikimic acid-G-¹⁴C,l-phenylalanine-U-¹⁴C andl-phenyllactic acid-U-¹⁴C into ellagic acid was very similar to the case of the radioactive gallic acid formation. Furthermore, regardless of the presence of unlabeled shikimic acid and/or phenylalanine, incorporation of the radioactivity of labeled gallic acid into ellagic acid occurred at a very high rate, suggesting the reciprocal radical reaction of gallic acid for the ellagic acid formation. The incorporation of labeled compounds into ellagitanins was also examined and their biosynthesis discussed further.     

Two-dimensional gel patterns of protein species during development of Drosophila embryos

Changes in the pattern of egg proteins of Drosophila melanogaster during the process of embryogenesis were investigated by high-resolution, two-dimensional polyacrylamide gel electrophoresis. We observed significant changes of egg proteins during embryogenesis. Three major classes were observed. Class I includes most proteins; these were found continuously throughout embryogenesis. Class II proteins appeared at certain times during embryogenesis and continued to be present in young larvae, or they were present in the ovary, disappeared once, and reappeared at later times. Class III proteins were found at limited times during embryogenesis. The appearance and disappearance of these proteins, which appear to be temporally related to developmental stages, should make them useful molecular markers for the analysis of embryogenesis.     

Properties of isolated extrachromosomal nucleoli fromTetrahymena pyriformis

Extrachromosomal nucleoli were isolated from log phase cells ofTetrahymena pyriformis (amicronucleate strain) in a highly purified state. Nucleoli located at the periphery of the macronucleus were detached from the nucleoplasmic mass of isolated macronuclei with agitation and separated from macronuclei by filtration through a Nuclepore membrane filter (pore size 5 m). The filtrate constitutes the crude nucleolar preparation, as judged by electron microscopy and DNA analysis. Further purification of the nucleoli was performed by isopycnic centrifugation of the filtrate in a Metrizamide density gradient. After this step, the purity of the nucleoli, as defined by rDNA content and measured by analytical CsCl centrifugation, was almost 100%. Electron microscopy of the purified nucleoli revealed structures that resemble those of in situ nucleoli. Undergraded 35S pre-rRNA, together with 26S and 17S rRNA, could be isolated from purified nucleoli. In vitro RNA synthetic activity was associated with isolated nucleoli. This activity is insensitive to low and high concentrations of -amanitin, indicating that the form I RNA polymerase is functioning.by M.F. TrendelenburgThis paper is dedicated to the late Dr. Yoshihiro Kato     

Antigenic Analysis of Polioviruses Isolated from a Child with Agammaglobulinemia and Paralytic Poliomyelitis after Sabin Vaccine Administration

A 3-year-old boy with agammaglobulinemia developed paralytic poliomyelitis on day 553 after being fed poliovaccine. Non-vaccine-like type 2 polioviruses were isolated from 22 stools obtained within 684 days after the onset of illness. Antigenic variations were observed among these viruses. The non-vaccine-like virus isolated 1 week after the onset of paralysis differed in virulence from the Sabin type 2 vaccine strain in the neurovirulence test in monkeys, and did not have the same antigenic character as the wild virulent strains. Another virus isolated on day 348 before the onset of illness was also classified as non-vaccine-like. However, the Sabin type 2 strain was shown to be homologous with this strain by the McBride test. Some Sabin-like particles were found in this stock virus. We may conclude that the non-vaccine-like virus isolates were derived from Sabin vaccine by antigenic variation that occurred during long-term multiplication in the intestinal tract.     

Direct production of l-ornithine from casein by commercial digestive enzymes and in situ activated arginase

There is a great demand for l-ornithine, which is used as a dietary supplement, and in the pharmaceutical industry. In the present study, when milk casein was hydrolyzed at 37 °C by using commercial digestive enzymes, namely, Pancreatin F and Protease A, a significant accumulation of l-ornithine in the hydrolysate and the simultaneous disappearance of l-arginine was noted. In a radiometric assay, transient but distinct arginase activity, which was sufficiently high for l-ornithine production, was detected in the hydrolysate for a certain period during casein hydrolysis. On the basis of the results of the enzymatic analyses, arginase was thought to be proteolytically generated from an inactive precursor, which may generally be contained in Pancreatin F, and ultimately degraded by further proteolysis. This conversion process using the above-mentioned digestive enzymes is useful for the production of l-ornithine directly from protein sources that are abundant in nature.     

Inverted terminal repeat sequence in the macronuclear DNA of Stylonychia pustulata

The structure of macronuclear DNA of a hypotrichous ciliate, Stylonychia pustulata, was examined by both electron microscopy and nucleotide sequence analysis. The DNA in the macronucleus consists of small linear molecules with average length of about 3400 base pairs (bp). Most, if not all, of these DNA molecules have identical inverted terminal repeat sequence of 20 nucleotide residues. This sequence is 5'-CCCCAAAACCCC-AAAACCCC.     

Central noradrenergic inhibition of gastric mucosal blood flow and acid secretion in rats

To investigate the role of central noradrenaline (NA) in gastric functions, changes in mucosal blood flow (MBF) and acid secretion following electrical stimulation of the lateral hypothalamic area (LHA) and the effects of NA on these parameters were examined in rats anesthetized with urethane. NA 10 μg/animal injected into the lateral ventricle decreased the basal value of both the gastric MBF and acid output, while the same dose of acetycholine or dopamine was without effect. Repetitive electrical stimulation of LHA at 10 cycles/sec, 0.5 mA, 2 msec for 10 min elicited a significant, reproducible increase in both gastric MBF and acid output. NA 10 μg/animal injected into the lateral ventricle completely blocked these increases induced by the electrical stimulation. These data suggest that a central noradrenergic inhibitory mechanism is involved in regulation of the gastric MBF and acid secretion.