Formation of a Tree having a Low Lignin Content

Received 30 September 2001/ Accepted in revised form 26 October 2001     

An 83-kDa embryonic-type nuclear antigen is detected within the germinal vesicles of oocytes of the ascidianHalocynthia roretzi

Summary Monoclonal antibodies were raised against germinal vesicles which were isolated from fully grown oocytes of the ascidianHalocynthia roretzi. Immunoblot analyses revealed that one of the antibodies, designated Hgv-2, recognized a single band with a molecular weight of about 83 kDa. The antibody, visualized by indirect immunohistochemistry, reacted only with the germinal vesicles of oocytes and did not react with test cells, follicle cells, and other somatic cells of the gonad. During embryogenesis the antigenicity was found in interphase nuclei of all embryonic cells. The antibody did not react with chromosomes or the mitotic apparatus. The antigenicity was retained by interphase nuclei of larval cells, but it disappeared from nuclei of juveniles about 7 days after metamorphosis.     

Selective production of glutamate by an immobilized marine blue-green alga,Synechococcus sp.

Summary Among 200 strains of marine bluegreen algae isolated from the coastal areas of Japan, the marine blue-green alga Synechococcus sp. NKBG 040607 excreted glutamate at the highest rate, 82.6% of total amino acids production being glutamate. Synechococcus sp. NKBG 40607 was immobilized in calcium alginate gel. Glutamate production by immobilized cells was double that of native cells. Maximal glutamate production (25 g/cm³ gel per day) of the immobilized cells was observed under a light intensity of 144 Einstein/m² per second at a cell concentration of 7.5 mg dry cells/cm³ gel. Immobilized cells of Synechococcus sp. can use nitrate as a nitrogen source. Immobilized marine Synechococcus sp. produced 0265 mg/cm³ gel of glutamate for 7 days in the presence of chloramphenicol.     

Respiration-Dependent Proton and Sodium Pumps in a Psychrophilic Bacterium, Vibrio sp. Strain ABE-1

Respiration-dependent proton and sodium flows in a psychrophilicbacterium, Vibrio sp. strain ABE-1, were examined. At alkalinepH, this bacterium grew without being affected by a proton conductor,carbonylcyanide m-chlorophenylhydrazone (CCCP). O₂-pulse intoanaerobic cell suspensions prepared with Na^$-free buffers inducedtransient alkalization in the presence of CCCP and acidificationat pH 8.5 and 6.5, respectively. However, using cells preparedwith Na^$-containing buffer, the transient pH changes of thecell suspension could be simultanously detected at both pHs.Several inhibitory experiments suggested that the acidificationand alkalization should be attributed to a respiration-dependentprimary H^$ pump and Na^$ pump, respectively, and that the latterwas similar to that first reported in a marine bacterium, Vibrioalginolyticus. This Na^$ pump may have supported the CCCP-resistantgrowth at alkaline pH. The H^$ and Na^$ pumps operated very actively at low temperatures,such as 5?C, and should markedly help sustain bacterial growthat low temperatures. (Received May 30, 1987; Accepted November 13, 1987)     

Induction of 3-Hydroxy-3-methylglutaryl CoA Reductase in Potato Tubers after Slicing, Fungal Infection or Chemical Treatment, and Some Properties of the Enzyme

Intact tubers of potato (Solanum tuberosum L. cv. Irish Cobblerand an interspecific hybrid between S. tuberosum and S. demissumcv. Rishiri) contain a very low activity of 3-hydroxy-3-methylglutaryl(HMG)-CoA reductase. The activity increased first in responseto slicing, and again in response to additional treatments suchas inoculation with an incompatible race of Phytophthora infestans,application of a hyphal wall component of the fungus or HgCl₂solution, and then decreased. Both the first and the secondincreases in activity in response to slicing and additionaltreatment with a hyphal wall component to elicit phytoalexinproduction were inhibited by blasticidin S. Properties of HMG-CoAreductase induced by slicing and by additional treatment withHgCl₂ or fungal inoculation were investigated. ² Present address: Faculty of Home Economics, Nagoya Women'sUniversity, Shioji-cho, Mizuho, Nagoya 467, Japan.     

Phosphorylation of five histone H1 subtypes of L5178Y cells at the exponential growth and mitotic phases

Histone H1 of cells of L5178Y, a mouse lympholeukemic cell line, consists of five molecular species designated as H1-I, II, III, IV, and V. The phosphorylation of these H1 subtypes was examined at the exponential growth phase and during mitosis, by BioRex 70 column chromatography and two-dimensional polyacrylamide gel electrophoresis. In exponentially growing cells, the degree of phosphorylation was different for each subtype. H1-II was the most highly phosphorylated, 1.8 phosphate residues per molecule, followed by H1-IV/V, 1.4, I, 0.8, and III, 0.5. In the mitotic phase, H1-II was also the most highly phosphorylated 6.0 phosphate residues per molecule, H1-IV/V, 3.5, I, 2.7, and III, 1.2. The phosphorylation started simultaneously among the subtypes after colcemid addition, and phosphorylated H1 subtypes accumulated linearly. The rate of incorporation of 32P into each H1 subtype was almost constant during colcemid treatment. During 4 h after colcemid addition, the phosphate residues incorporated into H1 did not dephosphorylated. The H1 kinase activities increased to six times higher during the colcemid treatment.     

Ultraviolet-sensitive ooplasmic factors are responsible for the development of an endoderm-specific alkaline phosphatase in the ascidian embryo

The ascidian egg contains muscle and endoderm determinants that play critical roles in the specification of muscle and endoderm cells, respectively. Endoderm cells of the ascidian embryo express alkaline phosphatase (AP) as a tissue-specific enzyme. We obtained egg fragments from the unfertilized eggs of Ciona savignyi by means of centrifugal force. The largest fragment (red fragments) contained the egg nucleus while other small fragments (black, clear and brown fragments) were anucleate. When inseminated, only red fragments developed into partial embryos, which showed only epidermis cell differentiation and, very rarely, AP activity. When red fragments were fused with other fragments, only black fragments promoted AP expression, suggesting that endoderm determinants were concentrated in the black fragments. A lower dose (1500 J/m²) of ultraviolet (UV) light did not eliminate the AP-promoting ability of black fragments, while this dose significantly repressed the ability to promote the expression of the muscle-marker. A higher dose (4500 J/m²) of UV light markedly reduced the AP-promoting activity of black fragments. These results suggest that factors for endodermal AP development are inactivated by UV irradiation, but are more resistant than muscle determinants.