A redescription of <Emphasis Type="Italic">Cryptocentrus crocatus</Emphasis> Wongratana,a redefinition of <Emphasis Type="Italic">Myersina</Emphasis> Herre (Acanthopterygii; Gobiidae), a key to the species,and comments on relationships

Myersina is redefined, based on the presence of an elongate first dorsal fin in at least the adult males, two preopercular pores, gill membranes fused in the ventral midline and either fused to the isthmus or forming a free fold over it, cycloid scales only on the body, and midline of predorsal region scaleless. It now includes four species traditionally assigned to Cryptocentrus but here placed in Myersina ("C". crocatus, "C". filifer, "C". pretoriusi, and "C". yangii). This concept of Myersina still retains the species originally assigned to it (M. macrostoma, M. lachneri, and M. nigrivirgata). The recently described M. larsonae belongs in Stonogobiops. These two genera almost definitely form a monophyletic group. However, it is possible that the species of Stonogobiops (the monophyly of which is well supported) could be more closely related to one or more species of Myersina than either is to other Myersina species, because the monophyly of the latter genus remains uncertain. Received: March 23, 2001 / Revised: September 7, 2001 / Accepted: October 18, 2001     

Cytoprotective effect of arginine deiminase on taxol-induced apoptosis in DU145 human prostate cancer cells

We purified and partially sequenced a cytostatic protein from the ASC-17D Sertoli cell-conditioned media (rSCCM) showing a molecular weight of 90 kDa with homodimeric composition. N-terminal amino acid analysis revealed that the protein was homologous to the arginine deiminase (ADI) of Mycoplasma arginini. We found ADI enzyme activity in rSCCM and the abolishment of the growth inhibitory effect by the supplement of L-arginine. Thus, we confirmed that the cytostatic activity in rSCCM was due to the depletion of extracellular L-arginine by ADI. Apparent increase of cell death or DNA fragmentation was not observed in DU145 cells cultured in the presence of ADI. Incubation of DU145 cancer cells with taxol resulted in a marked DNA fragmentation, whereas pretreatment with ADI or cycloheximide protected the cells from taxol-induced apoptosis. Preincubation of the cells with ADI inhibited S35-methionine incorporation into protein synthesis in a dose dependent manner. These data suggest that ADI-induced arginine depletion may inhibit protein synthesis, and result in the protection of apoptotic cell death that requires new protein synthesis.     

Antisense Oligonucleotide of Clusterin mRNA Induces Apoptotic Cell Death and Prevents Adhesion of Rat ASC-17D Sertoli Cells

Clusterin has been known to play important roles in cell-cell and/or cell-substratum interactions. Recently we reported the transient expression of clusterin in pancreatic endocrine cells during the early developmental stages and suggested a role in aggregating the endocrine cells for islet formation. In the present study, we have investigated the involvement of clusterin in cell-substratum interaction by the inhibition of clusterin synthesis using antisense oligonucleotide. The expression of clusterin was transiently increased as early as 2–8 h after plating the ASC-17D Sertoli cells to the culture flask, which was the period of cell attachment. In addition, up-regulation of clusterin mRNA was so much greater when the Sertoli cells were plated on the petri dish for the bacterial culture instead of in a animal cell culture flask that therefore, the cells failed to attach to it. These findings suggested that interruption of cell to plate substratum interaction might lead to over-expression of clusterin from Sertoli cells to induce cell to cell aggregation or, perhaps, to re-establish attachment with the substratum. Transfection of ASC-17D Sertoli cells with a 20-base antisense oligonucleotide against clusterin mRNA resulted in extracellular release of LDH and DNA fragmentation. Sertoli cell death by antisense oligonucleotide of clusterin was sequence specific and dose dependent. Treatment of antisense oligonucleotide induced a marked reduction of synthesis for clusterin protein, but not for clusterin mRNA expression, suggesting the translational suppression of clusterin by antisense oligonucleotide. Further, microscopic observation showed that more noticeable cell death was induced by treating the antisense prior to plating the cells than by treating after cell attachment to the plate. From these results, we speculate that down-regulation of clusterin expression in the anchorage-dependent Sertoli cells prevents them from attaching to the plate, and therefore induces cell death.     

Current Oscillations Under Voltage-Clamp Conditions: An Interplay of Series Resistance and Negative Slope Conductance

Using the patch-clamp technique, we observed profound oscillations of the whole-vacuole outward current across the tonoplast of Mesembryanthemum crystallinum L. (common ice plant). These current oscillations showed a clear voltage dependence and appeared at membrane potentials more positive than 90–100 mV. This paper describes the oscillations in terms of two separate mechanisms. First, the Mesembryanthemum vacuolar membrane shows a negative slope conductance at membrane potentials more positive than 100–120 mV. The fact that the oscillations and the negative slope conductance show a similar threshold potential suggests that (part of) the same mechanism is involved in both phenomena. The second mechanism involved is the voltage drop across the series resistance. As a result, the potential actually experienced by the vacuolar membrane deviates from the command potential defined by the patch-clamp amplifier. This deviation depends in an Ohmic manner on the current magnitude. We suggest that the interplay of the negative slope conductance and the voltage drop across the series resistance can cause a positive feedback which is responsible for the current oscillations. Received: 30 April 1999/Revised: 9 September     

Expression of SpC3, the sea urchin complement component,in response to lipopolysaccharide

The homologue of the vertebrate complement component C3 that is expressed in the coelomocytes of the purple sea urchin, Strongylocentrotus purpuratus, designated SpC3, was investigated for changes in response to immune challenge or injury. Immunoquiescent animals were used in this study because they have reduced or no detectable SpC3 in their coelomocytes or coelomic fluid (CF). Animals were injected with lipopolysaccharide (LPS) or sterile sea water (SSW, injury control). Changes in the amounts of SpC3 in coelomic fluid and in coelomocytes were then followed over time by Western blots and ELISA. Changes in mRNA from the SpC3 gene (Sp064) were also followed by RT-PCR. Although all animals responded to injury with increased levels of SpC3 in the coelomic fluid, those challenged with LPS had greater amounts of SpC3 in both CF and coelomocytes than those receiving SSW. In most of the animals receiving LPS, initial increases in SpC3 were observed within 1 h post-injection, while the earliest response in the animals receiving SSW was 6 h. The appearance of SpC3 in the coelomocytes was delayed compared to its appearance in CF, and was first detected several days after challenge. Changes in mRNA from the Sp064 gene paralleled the appearance of SpC3 in the coelomic fluid. Increases in the number of coelomocytes per milliliter of CF and in the percentage of coelomocytes that were SpC3+ also occurred after challenge with LPS or in response to injury, with a slightly greater increase in response to LPS. Although the changes in SpC3 were not as great as those identified previously for human C3 expressed in macrophages, the kinetics of the response are similar to that of acute-phase reactants in mammals.     

Differential physico-chemical tolerances of amphipod species revealed by field transplantations

Physico-chemical regimes of river systems are major determinants of the distributions and relative abundances of macroinvertebrate taxa. Other factors, however, such as biotic interactions, may co-vary with changes in physico-chemistry and concomitant changes in community composition. Thus, direct cause and effect relationships may not always be established from field surveys. Equally, however, laboratory studies may suffer from lack of realism in extrapolation to the field. Here, we use balanced field transplantation experiments to elucidate the role of physico-chemical regime in determining the generally mutually exclusive distributions of two amphipod taxa, Gammarus (two species) and Crangonyx pseudogracilis. Within two river systems in Ireland, the former species dominate stretches of well oxygenated, high-quality water, whereas the latter dominates stretches of poorly oxygenated, low-quality water. G. pulex and G. duebeni celticus did not survive in bioassay tubes in areas dominated by C. pseudogracilis, which itself survived in tubes in such areas. However, both C. pseudogracilis and Gammarus spp. survived equally well in tubes in areas dominated by Gammarus spp. Physico-chemical regime thus limits the movement of Gammarus spp. into C. pseudogracilis areas, but some other factor excludes C. pseudogracilis from Gammarus spp. areas. Since previous laboratory experiments showed high predation rates of Gammarus spp. on C. pseudogracilis, we propose that predation by the former causes exclusion of the latter. Hence, presumed effects of physico-chemical regime on macroinvertebrate presence/abundance may often require experimental field testing and appreciation of alternative explanations. Received: 14 June 1999 / Accepted: 20 January 2000     

Phenolic compounds from the leaves of Cornus controversa

Two novel phenolic compounds from the leaves of Cornus controversa (Cornaceae) were characterized as (-)-2,3-digalloyl-4-(E)-caffeoyl-L-threonic acid and (-)-2-galloyl-4-(E)-caffeoyl-L-threonic acid, using spectroscopic methods.     

Ab Initio Calculations of Vibrational Frequencies,Potential Functions of Internal Rotations and Vibrational Infrared and Raman Spectra for 3,3,3-Trifluoropropanal

The conformational behavior and structure of 3,3,3,-trifluoropropal have been investigated by utilizing ab initio calculations with the 6-31G^** basis set (valence double zeta basis with polarization functions on all atoms) at the restricted Hartree Fock (RHF), second-order Møller-Plesset perturbation (MP2), and Density Functional (B3LYP) levels. The molecule is predicted to have a cis Û gauche conformational equilibrium. Full optimization of the transition states was performed and the rotational barriers of both the CHO and CF₃ rotors were calculated. Vibrational frequencies were computed at the three levels and the zero-point corrections were included into the calculated asymmetric CHO rotational barrier. Complete vibrational assignments were made on the basis of normal coordinate calculations for both stable conformers of the molecule.     

Construction of a molecular linkage map and development of a molecular breeding technique

Conclusion  Although this research program is in the state of beginning, it seems like that the progress will be made more rapidly than expected. The reason is because new techniques and facilities derived from human genome research and other advanced genome program will overcome the current limitations and difficulties. Genome research cannot be accomplished by one or two research groups. That is why the program should be well organized and planned by scientists in various fields with common interest. Considering the tremendous amounts of time, money, and efforts required for performing genome research, the genome research programs should aim at concrete goals, such as getting new solutions that cannot be obtained by conventional approach, rather than remain as research for research is sake. This paper was presented at the 11th Symposium on Plant Biotechnology entitled “Plant Genes and Genetic Resources” organized by Gynheung An, held July 4–5, 1997, by the Botanical Society of Korea