Morphological differentiation of current-year shoots of deciduous and evergreen lianas in temperate forests in Japan

Morphological variation in current-year shoots within plants was examined in five deciduous and four evergreen liana species from temperate forests in Japan to elucidate the role differentiation in shoots. All lianas had both shoots that twined or developed adventitious roots to gain support on host materials (searcher shoots) and self-supporting shoots with no climbing structures (ordinary shoots). Searcher shoots were 20–295 times longer than ordinary shoots. The allometric relationships between stem length and leaf area differed between searcher and ordinary shoots, and the stem length for a given leaf area was greater in searcher shoots. Leaf area per shoot mass was 1.4–4.3 times higher in ordinary shoots because of the greater allocation to leaf biomass. Searcher shoots comprised only 1–6% of total shoots but 30–85% of total shoot length in deciduous lianas. Ordinary shoots accounted for 70–95% of the total leaf area in these liana species. These results suggest that the exploration of new space was primarily achieved by searcher shoots, whereas a large proportion of current photosynthetic production was achieved by ordinary shoots. The range of stem length and leaf mass ratio of ordinary shoots was similar to that in shoots of tree species. Specialization of shoots in lianas is discussed.     

Dynamics of mitochondrial structure during apoptosis and the enigma of Opa1

“The large scale remodeling of mitochondria during apoptosis is a necessary step for the complete release of cytochrome c” has been a tenet since 2002. However, more recent findings strongly indicate that the large-scale remodeling previously described actually takes place after the release of cytochrome c and in a caspase-dependent manner, bringing into question whether mitochondria remodeling is necessary. In a more recent article, however, it was shown that a much more subtle form of remodeling is taking place which is only observable by electron tomography. In the Bcl-2 inhibitable Bax/Bak-dependent intrinsic pathway of apoptosis, the release of cytochrome c from mitochondria is a consequence of two carefully coordinated events: formation of outer membrane pores and opening of crista junctions triggered by Opa1 oligomer disassembly, and both steps are necessary for the complete release of cytochrome c. We review the recent literature pertaining to the coordinated release of cytochrome c during cell death.     

Organization of the Mitochondrial Genome of Antarctic Krill <Emphasis Type="Italic">Euphausia superba</Emphasis> (Crustacea: Malacostraca)

We determined the nearly complete DNA sequence of the mitochondrial genome of Antarctic krill Euphausia superba (Crustacea: Malacostraca), one of the most ecologically and commercially important zooplankters in Antarctic waters. All of the genome sequences were purified by gene amplification using long polymerase chain reaction (PCR), and the products were subsequently used as templates for either direct sequencing using a primer-walking strategy or nested PCR with crustacea-versatile primers. Although we were unable to determine a portion of the genome owing to technical difficulties, the sequenced position, 14,606 bp long, contained all of the 13 protein-coding genes, 19 of the 22 transfer RNA genes, and the large subunit as well as a portion of the small subunit ribosomal RNA genes. Gene rearrangement was observed for 3 transfer RNA genes (tRNA^Cys, tRNA^Tyr, and tRNA^Trp) and the 2 leucine tRNA genes.     

Life cycle of CO2-emissions from electric vehicles and gasoline vehicles utilizing a process-relational model

This article aims at estimating life cycle CO₂ emissions from electric vehicles (EV) and gasoline vehicles (GV), although the estimation in this study is not an LCA according to ISO14040s. For this purpose, a mathematical tool called the Process-relational model was developed. The Process-relational model is used for establishing life cycle inventories. The model has a structure which improved the principle of input-output analysis in econometrics that only one product is generated by one process. This model enabled us to overcome difficulties of LCA in retracing complicated repercussions among production systems. Then, life cycle CO₂, emissions from electric vehicles (EV) and gasoline vehicles (GV) were estimated with this model. Estimated results indicated that the manufacture and driving of EV resulted in less CO₂ emissions than chose of GV. However, the difference between EV and GV dramatically changed depending on traffic situations. Namely, the difference became larger as the average velocity of the vehicles became lower. We also compared CO₂, emission from manufacturing EV with that from driving EV. The share of manufacture was shown to increase in total CO₂, emissions as the average velocity of the EV became higher. In conclusion, we clarified the direction of research and development of EV and GV for reducing the life cycle CO₂.     

Contactin-associated protein (Caspr) 2 interacts with carboxypeptidase E in the CNS

To identify proteins interacting with the intracellular domain of the neural cell adhesion molecule contactin-associated protein 2 (Caspr2), yeast two-hybrid screening was performed. We identified carboxypeptidase E (CPE) as a Caspr2-interacting candidate protein. Glutathione S -transferase pull-down and immunoprecipitation analyses indicated that Caspr2 was associated with CPE in vitro and in vivo . Both Caspr2 and CPE were expressed predominantly in the CNS. Immunohistochemical analyses revealed that both Caspr2- and CPE-like immunoreactivities were found to co-localize in the apical dendrites and cell bodies of rat cortical neurons. In subcellular localization analysis, Caspr2- and CPE-like immunoreactivities were co-migrated in the fractions of Golgi/ER. Additionally, in COS-7 cells co-transfected with CPE and Caspr2 cDNAs, Caspr2- and CPE-immunoreactivities were co-localized in both Golgi and membrane, whereas it was only observed in Golgi of either COS-7 cell transfected with CPE or Caspr2 cDNA alone. It is known that the membrane-bound form of CPE functions as a sorting receptor of prohormones in the trans -Golgi network. Taken together, our data suggest that CPE may be a key molecule to regulate Caspr2 trafficking to the cell membrane.     

Deep water stratification in deep caldera lakes Ikeda, Towada, Tazawa, Kuttara, Toya and Shikotsu

From six deep caldera lakes in Japan, namely lakes Ikeda, Towada, Tazawa, Toya, Kuttara and Shikotsu (in Japanese referred to as Ikedako, Towadako, Tazawako, Toyako, Kuttarako and Shikotsuko), fine resolution profiles of temperature, electrical conductivity, dissolved oxygen and pH have been measured. Measurements were conducted just after deep circulation from the end of March to the end of May 2005. Lake Ikeda and Lake Towada did not undergo a complete turnover. Both showed meromictic features with a clear interface separating the recirculated mixolimnion from the deeper monimolimnion. Lake Tazawa and Lake Toya showed a complete turnover in winter 2004/05, while in Lake Kuttara and Lake Shikotsu, a deep water body remained throughout winter due to pressure effects on the temperature of maximum density. Although these deep waters were never fully recycled into the mixolimnion, they presented themselves as well supplied with oxygen and well circulated within themselves. Where overturn had not been complete small gradients in the oxygen profile, pH profiles and electrical conductivity profiles could be detected. However only in Lake Towada were concentrations of dissolved substances and gradients high enough to have decisive impact on the circulation pattern.     

Target Antigen of Vaccinia-Infected Cells Recognized by Virus-Specific Cytotoxic T Lymphocytes

A vaccinia-specific target antigen for recognition of anti-vaccinia cytotoxic T lymphocytes (CTL) was found to be formed on the surface of infected cells through two distinct processes. In the first phase, the expression of the target antigen was dependent on the dose of inoculated virus, without specific protein synthesis. The target antigen seems to be produced by virus-cell fusion. In the second phase, the expression of the target antigen was accompanied by synthesis of an early protein. In spite of the difference in their mode of expression, the first-phase and the second-phase target antigens were cross-reactive in cytotoxicity inhibition assays. Cowpox virus, CPR Cl strain, brought about a lower response than vaccinia virus, IHD-J strain, in both sensitization of CTL and formation of CTL-susceptible cells at both the first and the second phase. The cross-reactive, but inefficient, recognition of anti-vaccinia CTL for cowpox-infected cells suggested a slight difference in the target antigens of the two viruses. Attempts to identify the target antigen were then made by comparing the polypeptide composition of vaccinia virus, cowpox virus, and their recombinants. SDS-PAGE analysis of trypsinactivated viruses revealed 44K (cowpox)/45K (vaccinia) polypeptides which corresponded to the difference in target cell formation. Trypsinization of the viruses also increased the ability of the virus to induce the production of CTL-susceptible target cells.     

Protein kinase C and linoleic acid-induced inhibition of melanogenesis

Linoleic acid has been shown to inhibit melanogenesis in cultured B16 mouse melanoma cells. We report here the possible involvement of protein kinase C (PKC) in linoleic acid-induced inhibition of melanogenesis in B16 cells. A single PKC subspecies (alpha-PKC) was detected in B16 cells. The enzyme was activated by linoleic acid in vitro. The effective concentrations at which PKC was activated (25 microM; maximum response) were consistent with those for the inhibition of melanogenesis in cell culture system. In addition, the permeable diacylglycerol 1-oleoyl-2-acetyl glycerol that activates PKC also inhibits melanogenesis at 100 microM. These results suggest that activation of PKC plays a pivotal role in the linoleic acid-induced inhibition of melanogenesis in B16 cells.