Effects of water level fluctuation on the growth ofNelumbo nucifera Gaertn. in Lake Kasumigaura,Japan

Investigations were made of the growth ofNelumbo nucifera, an aquatic higher plant, in a natural stand in Lake Kasumigaura. A rise of 1.0 m in the water level after a typhoon in August 1986 caused a subsequent decrease in biomass ofN. nucifera from the maximum of 291 g d.w. m⁻² in July to a minimum of 75 g d.w. m⁻². The biomass recovered thereafter in shallower regions. The underground biomass in October tended to increase toward the shore. The total leaf area index (LAI) is the sum of LAI of floating leaves and emergent leaves. The maximum total LAI was 1.3 and 2.8 m² m⁻² in 1986 and 1987, respectively. LAI of floating leaves did not exceed 1 m² m⁻². The elongation rates of the petiole of floating and emergent leaves just after unrolling were 2.6 and 3.4 cm day⁻¹, respectively. The sudden rise in water level (25 cm day⁻¹) after the typhoon in August 1986 caused drowning and subsequent decomposition of the mature leaves. Only the young leaves were able to elongate, allowing their laminae to reach the water surface. The fluctuation in water level, characterized by the amplitude and duration of flooding and the time of flooding in the life cycle, is an important factor determining the growth and survival ofN. nucifera in Lake Kasumigaura.     

Growth analysis ofQuercus serrata seedlings withinMiscanthus sinensis grass canopies differing in light availability

The effects of different light regimes on the survival, growth and morphology ofQuercus serrata seedlings were studied in canopies ofMiscanthus sinensis. The seedlings of various ages (0–3 yr) were grown in three light regimes: under a denseM. sinensis canopy (TG plot) receiving 2.5%–8.7% of full sunlight, under a relatively sparse canopy (SG plot) receiving 3.8%–16.1% of light and in an adjacent open site (NG plot). There was a little difference in the survival ofQ. serrata seedlings among the three plots. Height and diameter of stem and total leaf area of the seedlings were significantly lower in the shadier plots. However, the first (bottom) flush of the stem was significantly longer in the TG plot than in the NG and SG plots. Total dry weights of individual 1- and 2-yr-oldQ. serrata seedlings in the TG plot were reduced to about one-twelfth of those in the NG plot. Although the relative proportion in dry weight of each organ did not differ significantly among the plots, leaf area ratio, specific leaf area and stem height per unit dry weight were significantly higher in shadier plots. The leaf area per unit stem height was increased considerably in the sunnier plots.     

Preferential ADP-ribosylation of arginine-3 in synthetic heptapeptide Leu-Arg-Arg-Ala-Ser-Leu-Gly.

Hen liver nuclear ADP-ribosyltransferase modified the synthetic heptapeptide Kemptide (Leu-Arg-Arg-Ala-Ser-Leu-Gly) at arginine-2 and/or arginine-3. Trypsin treatment of ADP-ribosyl-Kemptide revealed that the ADP-ribosylation of arginine-3 was constantly more abundant than that of arginine-2. ADP-ribosylation of Kemptide suppressed the subsequent phosphorylation by cyclic AMP-dependent protein kinase.     

Lung burden of green nickel oxide aerosol and histopathological findings in rats after continuous inhalation

There are few inhalation studies of nickel carcinogenesis. In this study, Wistar male rats were exposed to green nickel oxide (NiO(G)) aerosols (mass median aerodynamic diameter, 0.6 μm) for 7 h/d, 5 d/wk for up to 12 mo. The average exposure concentration was controlled at 0.3 and 1.2 mg/m³ during the exposure. For histopathological examination and measurement of the nickel concentration in rat organs, the rats were sacrificed at 3, 6, and 12 mo of exposure and 8 mo clearance period following 12 mo of exposure. The nickel content in rat lungs that was observed up to 2.6 mg after 12 mo exposure, was proportional to the exposure concentration during the exposure. The clearance of the nickel from the lungs was very slow and the biological half time was determined 7.7 mo. Although the rats were exposed continuously to NiO(G), for 12 mo and kept for 8 mo clearance period, there were no malignant tumors in any of the exposed animals.     

Construction of protocellular structures under simulated primitive earth conditions

We have developed experimental approaches for the construction of protocellular structures under simulated primitive earth conditions and studied their formation and characteristics. Three types of envelopes; protein envelopes, lipid envelopes, and lipid-protein envelopes are considered as candidates for protocellular structures. Simple protein envelopes and lipid envelopes are presumed to have originated at an early stage of chemical evolution, interaction mutually and then evolved into more complex envelopes composed of both lipids and proteins.Three kinds of protein envelopes were constructedin situ from amino acids under simulated primitive earth conditions such as a fresh water tide pool, a warm sea, and a submarine hydrothermal vent. One protein envelope was formed from a mixture of amino acid amides at 80 °C using multiple hydration-dehydration cycles. Marigranules, protein envelope structures, were produced from mixtures of glycine and acidic, basic and aromatic amino acids at 105 °C in a modified sea medium enriched with essential transition elements. Thermostable microspheres were also formed from a mixture of glycine, alanine, valine, and aspartic acid at 250 °C and above. The microspheres did not form at lower temperatures and consist of silicates and peptide-like polymers containing imide bonds and amino acid residues enriched in valine. Amphiphilic proteins with molecular weights of 2000 were necessary for the formation of the protein envelopes.Stable lipid envelopes were formed from different dialkyl phospholipids and fatty acids.Large, stable, lipid-protein envelopes were formed from egg lecithin and the solubilized marigranules. Polycations such as polylysine and polyhistidine, or basic proteins such as lysozyme and cytochromec also stabilized lipid-protein envelopes.     

Promotion of Flowering by DNA Base Analogues and Changes in Acid Phosphatase and Peroxidase Isozyme Composition in Dark-Grown Arabidopsis thaliana

A DNA base analogue, 5-bromodeoxyuridine (BUdR), promoted floweringof Arabidopsis thaliana in short and long photoperiods and evenin total darkness. The promotive effect of BUdR was nullifiedby thymidine which had a weak inhibitory effect by itself. AnotherDNA base analogue, 5-fluorodeoxyuridine (FUdR), inhibited theflowering at a low concentration (10^–8 M), but markedlyenhanced the promotive effect of BUdR if they were present togetherin the culture medium. In the flower-promoting medium containing both BUdR and FUdR,the number of acid phosphatase isozymes decreased temporarily,followed by an increase to the control level with a prolongedculture period. The number of peroxidase isozymes was greaterin plants grown in the medium with BUdR or BUdR $ FUdR thanin those without them. (Received October 22, 1987; Accepted March 25, 1988)     

Alpha-interferon in Kikuchi’s disease

In Japan, histiocytic necrotizing lymphadenitis (Kikuchi’s disease) is a relatively common reactive lesion affecting lymph nodes, but the histogenesis and pathogenesis of the disease have not been clarified. Alpha-interferon has a role in the body’s defense against, viral infections. Using a polyclonal antibody to human alpha-interferon, we found numerous cells, mainly histiocytes, containing alpha-interferon in affected foci in the lymph nodes from 24 patients with Kikuchi’s disease. Tubuloreticular structures, thought by some authors to be associated with the production of interferon, were detected by electron microscopy in histiocytes, activated lymphocytes and vascular endothelial cells in the affected foci. These results suggested that the formation of tubuloreticular structures is a secondary phenomenon following stimulation by alpha-interferon. Further, the activity of 2′–5′ oligoadenylate synthetase, which is induced by alpha-interferon and enhanced during the early or active stage of viral infection, showed increased levels of activity in the active stage of Kikuchi’s disease and decreased to normal levels in the convalescent stage 2 weeks later. These results suggested the possibility of a viral etiology for Kikuchi’s disease.     

Complement-dependent lysis of tumor cells by a baboon IgM antibody to a tumor-associated antigen

Summary We developed a high-titer polyclonal antiserum to a glycoprotein tumor-associated antigen (TAA) by immunization of a baboon with the purified glycoprotein antigen. The baboon serum was fractionated into IgG and IgM components by DEAE Affi-Gel blue chromatography. The ability of the baboon IgM anti-TAA antibody to effect tumor cell lysis in the presence of complement was tested using a chromium-release assay. The baboon antibody was able to lyse melanoma target cells (20.8%–71.4% cytolysis), breast carcinoma cells (36.5%–38.9% cytolysis), and a neuroblastoma cell line (35.5% cytolysis) in the presence of complement but did not effect significant lysis of autologous lymphoblastoid cell lines (4.9% cytolysis) or peripheral blood lymphocytes from healthy volunteers (12.6% cytolysis). Cytolysis of melanoma target cells was completely inhibited by preabsorption of the IgM anti-TAA antibody with UCLA-SO-M14 (M14) cells and partially inhibited by preabsorption with several other melanoma cell lines. There was no significant inhibition of tumor cell lysis after preabsorption of the antibody with lymphoblastoid cell lines. Complement-dependent lysis of M14 targets could be blocked by addition of the purified antigen to the antibody prior to incubation with the tumor cells. Our results suggest that the glycoprotein TAA resides on the tumor cell surface and that the baboon IgM anti-TAA antibody recognizes the antigen on the cell surface and is able to fix complement and effect the lysis of the tumor cells.     

A nomenclature for the genes encoding the chlorophylla/b-binding proteins of higher plants

We propose a nomenclature for the genes encoding the chlorophylla/b-binding proteins of the light-harvesting complexes of photosystem I and II. The genes encoding LHC I and LHC II polypeptides are namedLhca1 throughLhca4 andLhcb1 throughLhcb6, respectively. The proposal follows the general format recommended by the Commision on Plant Gene Nomenclature. We also present a table for the conversion of old gene names to the new nomenclature.     

Deletion analysis of the Taka-amylase A gene promoter using a homologous transformation system in Aspergillus oryzae.

The Taka-amylase A gene (amyB) of Aspergillus oryzae is induced by starch or maltose. The molecular mechanism of the induction was investigated using a fusion of the amyB promoter and the Escherichia coli uidA gene encoding beta-glucuronidase (GUS). To identify the region responsible for high-level expression and regulation within the amyB promoter, a series of deletion promoters was constructed and introduced into the A. oryzae met locus by homologous recombination. Deletion of the region between -377 to -290 (the number indicates the distance in base pairs from the translation initiation point (+1) to the deletion end point) significantly reduced of the GUS activity, but slight reduction of the GUS activity was observed in deletions up to -377. Northern blot analysis showed that reduction of the GUS activity depended upon the expression level of the GUS gene. The region between -377 to -290 is suggested to include the sequence required directly for high-level expression and regulation of the amyB gene.