Formation of a Tree having a Low Lignin Content

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

Global and temporal regulation of gene expression in Xenopus kidney cells in response to presumed microgravity generated by 3D clinostats.

We documented changes in morphology and gene expression of the renal epithelial cell line A6 derived from Xenopus leavis adult kidney induced by long-term culturing with three dimensional clinostats. An oligo microarray analysis on A6 cells showed that mRNA levels of 52 out of 8091 genes were significantly altered in response to clinorotation. Upregulation or downregulation of gene expression became evident on day 8 and day 10 while there was no significant change on day 5. However, on day 15, expression of 18 out of 52 genes resumed to the levels similar to its original levels while remaining 33 genes maintained altered levels of expression. Quantitative analyses of gene expression by real-time PCR confirmed that changes in mRNA levels of selected genes were found only under clinorotation but not under hypergravity (7 G) and ground control (1 G). Morphological changes including loss of dome-like structures, disassembly of E-cadherin adherence junctions and disassembly of cortical actin were also observed over 10 days of culturing with clinorotation. The results revealed genes which expression was altered specifically in A6 cells cultured under clinorotation.     

Pro----leu change at position 102 of prion protein is the most common but not the sole mutation related to Gerstmann-Str?ussler syndrome

The host-encoded prion protein (PrP) is a component of transmissible amyloid deposited in the brains affected by Gerstmann-Str?ussler syndrome (GSS). Recently GSS in two unrelated Caucasian families has been reported to be linked to an amino acid change in PrP codon 102, proline to leucine (Leu102). However, it has not been clear whether the change is commonly found to GSS regardless of ethnic origin. We report here that Leu102 is also found in all the Japanese GSS patients tested. Interestingly, one French GSS patient was found to have another change, alanine to valine in codon 117 (Val117), instead of Leu102. Our results indicate that Leu102 is closely related to GSS irrespective of ethnic origin, but not the sole mutation related to GSS. Val117 may also be related to GSS.     

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)