Phenology of the rhodomelarian algae Neorhodomela aculeata and Ceramium kondoi and their survival strategies against herbivorous snails

The seasonal growth and reproductive phenology of Neorhodomela aculeata (Perestenko) Masuda and Ceramium kondoi Yendo, and the food preferences of herbivorous snails were examined to elucidate (i) why snails select the fronds of N. aculeata for their habitat; and (ii) the survival strategies of the two red algae under grazing pressures. The maximal lengths and weights of both algal species were recorded for each season over a 12‐month period beginning with the spring of 2003. C. kondoi grew in length at a faster rate than N. aculeate, whereas the turf alga N. aculeata produced new branches from the tips of broken branches. The reproductive period of C. kondoi was between the spring and summer but the reproductive organs of N. aculeata were observed throughout the year. The algal loss rate of fresh N. aculeata to snails was low but snails had a food preference for N. aculeata when compared to C. kondoi in an artificial food experiment. These results indicate that snails may adapt to chemical compounds characteristic of N. aculeata and that the alga further reduces predation damage by its structural resistance. In conclusion, the survival strategies of C. kondoi appear to be rapid growth, seasonal sexual reproduction, and a delicately branched frond morphology that reduces stable feeding patterns of its predators plus high tissue nitrogen content, whereas the survival strategy of N. aculeata includes regenerative growth responses, structural toughness and chemical defenses while under the grazing pressure of herbivorous snails.     

Molecular characterization of thyroid hormone receptors from the leopard gecko, and their differential expression in the skin

Thyroid hormones (THs) play crucial roles in various developmental and physiological processes in vertebrates, including squamate reptiles. The effect of THs on shedding frequency is interesting in Squamata, since the effects on lizards are quite the reverse of those in snakes: injection of thyroxine increases shedding frequency in lizards, but decreases it in snakes. However, the mechanism underlying this differential effect remains unclear. To facilitate the investigation of the molecular mechanism of the physiological functions of THs in Squamata, their two specific receptor (TRalpha and beta) cDNAs, which are members of the nuclear hormone receptor superfamily, were cloned from a lizard, the leopard gecko, Eublepharis macularius. This is the first molecular cloning of thyroid hormone receptors (TRs) from reptiles. The deduced amino acid sequences showed high identity with those of other species, especially in the C and E/F domains, which are characteristic domains in nuclear hormone receptors. Expression analysis revealed that TRs were widely expressed in many tissues and organs, as in other animals. To analyze their role in the skin, temporal expression analysis was performed by RT-PCR, revealing that the two TRs had opposing expression patterns: TRalpha was expressed more strongly after than before skin shedding, whereas TRbeta was expressed more strongly before than after skin shedding. This provides good evidence that THs play important roles in the skin, and that the roles of their two receptor isoforms are distinct from each other.     

中国银斑蛛属二新种(蜘蛛目:球蛛科)

记述了球蛛科银斑蛛属2新种:黄桑银斑蛛Argyrodes huangsangensis sp.nov. 和菱腹银斑蛛Argyrodes rhomboides sp.nov..并对环银斑蛛Argyrodes orbitus Zhu, 1988的雌蛛进行了补充描述.     

Cloning and characterization of the lactate dehydrogenase genes from<Emphasis Type="Italic">Lactobacillus</Emphasis> sp. RKY2

Lactic acid is an environmentally benign organic acid that could be used as a raw material for biodegradable plastics if it can be inexpensively produced by fermentation. Two genes (IdhL andIdhD) encoding the L-(+) and D-(−) lactate dehydrogenases (L-LDH and D-LDH) were cloned fromLactobacillus sp., RKY2, which is a lactic acid hyper-producing bacterium isolated from Kimchi. Open reading frames ofIdhL for andIdhD for the L and D-LDH genes were 962 and 998 bp, respectively. Both the L(+)- and D(−)-LDH proteins showed the highest degree of homology with the L- and D-lactate dehydrogenase genes ofLactobacillus plantarum. The conserved residues in the catalytic activity and substrate binding of both LDHs were identified in both enzymes.     

Development and evaluation of a protein microarray chip for diagnosis of hepatitis C virus

A protein chip diagnostic kit was developed for the diagnosis of hepatitis C virus (HCV) based on the protein chip technique and the immuno-concentration method. This kit was designed for low-density protein chips and also for the availability of multiple sample screening. Applicability of the chip was evaluated using 96 blood specimens and the results were compared to results of an anti-HCV enzyme immunoassay (EIA) test. With further development, the technology associated with the development of this chip could be applied to the simultaneous detection of multiple protein-protein, protein-ligand interactions.     

PathoPlant: a database on plant-pathogen interactions

Pathogen recognition and signal transduction during plant pathogenesis is essential for the activation of plant defense mechanisms. To facilitate easy access to published data and to permit comparative studies of different pathogen response pathways, a database is indispensable to give a broad overview of the components and reactions so far known. PathoPlant has been developed as a relational database to display relevant components and reactions involved in signal transduction related to plant-pathogen interactions. On the organism level, the tables 'plant', 'pathogen' and 'interaction' are used to describe incompatible interactions between plants and pathogens or diseases. On the molecular level, plant pathogenesis related information is organized in PathoPlant's main tables 'molecule', 'reaction' and 'location'. Signal transduction pathways are modeled as consecutive sequences of known molecules and corresponding reactions. PathoPlant entries are linked to associated internal records as well as to entries in external databases such as SWISS-PROT, GenBank, PubMed, and TRANSFAC. PathoPlant is available as a web-based service at http://www.pathoplant.de.     

Group IB secretory phospholipase A2 promotes matrix metalloproteinase-2-mediated cell migration via the phosphatidylinositol 3-kinase and Akt pathway

Secretory phospholipase A(2) (sPLA(2)), abundantly expressed in various cells including fibroblasts, is able to promote proliferation and migration. Degradation of collagenous extracellular matrix by matrix metalloproteinase (MMP) plays a role in the pathogenesis of various destructive disorders, such as rheumatoid arthritis, tumor invasion, and metastasis. Here we show that group IB PLA(2) increased pro-MMP-2 activation in NIH3T3 fibroblasts. MMP-2 activity was stimulated by group IB PLA(2) in a dose- and time-dependent manner. Consistent with MMP-2 activation, sPLA(2) decreased expression of type IV collagen. These effects are due to the reduction of tissue inhibitor of metalloproteinase-2 (TIMP-2) and the activation of the membrane type1-MMP (MT1-MMP). The decrease of TIMP-2 levels in conditioned media and the increase of MT1-MMP levels in plasma membrane were observed. In addition, treatment of cells with decanoyl Arg-Val-Lys-Arg-chloromethyl ketone, an inhibitor of pro-MT1-MMP, suppressed sPLA(2)-mediated MMP-2 activation, whereas treatment with bafilomycin A1, an inhibitor of H(+)-ATPase, sustained MMP-2 activation by sPLA(2). The involvement of phosphatidylinositol 3-kinase (PI3K) and Akt in the regulation of MMP-2 activity was further suggested by the findings that PI3K and Akt were phosphorylated by sPLA(2). Expression of p85alpha and Akt mutants, or pretreatment of cells with LY294002, a PI3K inhibitor, attenuated sPLA(2)-induced MMP-2 activation and migration. Taken together, these results suggest that sPLA(2) increases the pro-MMP-2 activation and migration of fibroblasts via the PI3K and Akt-dependent pathway. Because MMP-2 is an important factor directly involved in the control of cell migration and the turnover of extracellular matrix, our study may provide a mechanism for sPLA(2)-promoted fibroblasts migration.     

GENETIC DATA HINT AT A COMMON DONOR REGION FOR INVASIVE ATLANTIC AND PACIFIC POPULATIONS OF GRACILARIA VERMICULOPHYLLA (GRACILARIALES,RHODOPHYTA)1

Gracilaria vermiculophylla (Ohmi) Papenf., an agar‐producing red alga introduced from northeast Asia to Europe and North America, is often highly abundant in invaded areas. To assay its genetic diversity and identify the putative source of invasive populations, we analyzed the mitochondrial cytochrome c oxidase subunit I (cox1) gene from 312 individuals of G. vermiculophylla collected in 37 native and 32 introduced locations. A total of 19 haplotypes were detected: 17 in northeast Asia and three in Europe and eastern and western North America, with only one shared among all regions. The shared haplotype was present in all introduced populations and in ～99% of individuals in the introduced areas. This haplotype was also found at three native locations in east Korea, west Japan, and eastern Russia. Both haplotype and nucleotide diversities were extremely low in Europe and North America compared to northeast Asia. Our study indicates that the East Sea/Sea of Japan is a likely donor region of the invasive populations of G. vermiculophylla in the east and west Atlantic and the east Pacific.     

High production of laccase by a new basidiomycete, <Emphasis Type="Italic">Trametes</Emphasis> sp

A new basidiomycete, Trametes sp. 420, produced laccase at 6,810 U l⁻¹ (268 mg, 25.4 U mg⁻¹ protein for guaiacol) in glucose medium and 7,870 U l⁻¹ (310 mg) in cellobiose medium with induction by 0.5 mM Cu²⁺ and 6 mM o-toluidine. Laccase isozyme E (LacE) was the sole laccase in the fermentation products. It was stable at pH 5–9 and below 70°C over 30 min. The K _m values of LacE for four substrates (guaiacol ABTS, 2,6-dimethoxyphenol and syringaldazine) varied from 5 to 245 μM. The activity of LacE was strongly inhibited by NaN₃ but not by EDTA or dimethylsulfoxide. LacE at 0.5 U l⁻¹ could decolorize industrial dyes. The open reading frame of the lacE gene was 2,130 bp and was interrupted by 10 introns. It displayed a high homology to laccases from other fungi. Pingui Tong and Yuzhi Hong contributed equally to the study