Molecular characterization of the brain secretory peptides, PTTH and bombyxin, of Bombyx mori is reviewed. PTTH is a 30-kDa homodimeric glycoprotein, the monomer of which consists of 109 amino acids. Two monomers are held together by a disulfide bond. cDNA and gene coding for PTTH were cloned and the precursor protein for PTTH monomer was deduced. A novel 5-kD brain secretory peptide named bombyxin has been discovered from Bombyx brain. Bombyxin is highly homologous to vertebrate insulin-family peptides and possesses the prothoracicotropic activity when injected into brain-removed pupae of a heterologous moth, Samia cynthia ricini, though inactive to Bombyx from which it was derived. cDNA and gene coding for bombyxin were cloned, preprobombyxin protein was deduced, and posttranslational processing to generate mature bombyxin was suggested. The Bombyx genome contains highly multiple copies of the gene coding for bombyxins. Immunohistochemically, PTTH- and bombyxin-producing brain neurosecretory cells were identified.
Lignin peroxidase (LiP), laccase (LA) and manganese peroxidase (MnP) of white-rot basidiomycetes such as Phanerochaete chrysosporium, Coliorus versicolor, Phlebia radiata and Pleurotus eryngii catalyze oxidative degradation of lignin substructure model compounds and synthetic lignins (DHPs). Side chain- and aromatic ring cleavage products of both phenolic and non-phenolic substrates oxidized by LiP were isolated and characterized by NMR and MS. The cleavage mechanism was elucidated by using 18O, 2H, and 13C labeled lignin substructure dimers with 18O 2 and H218O. Recent studies suggested that LiP is capable of oxidizing lignin directly at the protein surface via a long-range electron transfer process. LA and MnP, which oxidize phenolic but not non-phenolic moieties, generally degrade lignin stepwise from phenolic moieties. However, recent studies indicated that MnP and LA can degrade both phenolic and non-phenolic aromatic moieties of lignin with some special mediators.
Tobamovirus is a positive-strand RNA virus of plants. Its single-stranded RNA genome replicates via the negative-strand RNA. In this review, we describe our current knowledge about viral and host factors associated with tobamovirus RNA replication and discuss the replication mechanisms. We also mention the usefulness of tobamovirus genomes as vectors.
Based on the stratigraphically well sorted material from Japan and southern Sakhalin, the ammonoid species belonging to the genus Desmoceras are classified as follows in ascending order: D. latidorsatum (Michelin) (Middle to mid-Upper Albian), D. dawsoni shikokuense (Yabe and Shimizu) (Upper Albian), D. kossmati Matsumoto (uppermost Albian-Lower Cenomanian), D. japonicum Yabe (uppermost Albian-Cenomanian), and D. ezoanum Matsumoto (mid-Upper Cenomanian-mid-Lower Turonian). D. japonicum can be subdivided into the earlier and later subspecies. D. poronaicum Yabe is a junior synonym of D. japonicum. Despite the scarcely ornamented shell, each taxon can be defined by its own characters.
Well-exposed transgressive and regressive sequence of the Santonian Taneichi Formation occurs along the Pacific Coast of northeastern Honshu, Japan. Although the studied sequence is of only 60 m thickness, the outcrops show various sedimentary facies accompanied with two disconformities, suggesting a small-scale but substantial sea-level rise and fall. Orientations of some sedimentary structures, such as ripples and bipolar cross-stratification, indicate that the paleostrandline of the Taneichi Formation made a high angle with the present coastline. Compared with the Santonian Kunitan Formation that is exposed about 50 km south of the studied section and that consists of thick deposits due to an incised valley sedimentation, the thin sediments of the Taneichi Formation are thought to have been supplied from the broad coastal plain along the eastern margin of the Eurasian continent.
Using a microcrystal of the feast/famine regulatory protein (FFRP) pot0434017 (FL11), a cryo-electron micrograph was taken, showing a projection of cylinder-like assemblies packed parallel to each other. This electron micrograph was processed in the Fourier space by selecting spots reflecting the packing and, in addition, those reflecting stacking of units inside the cylinders. Twenty seven subimages were selected, each containing three cylinders of 24 discs each, running nearly parallel to each other. By averaging these images and in combination with another average showing a different view [Ishijima, S. A., Clowney, L., and Suzuki, M. (2004) Proc. Jpn. Acad., Ser. B 80, 183-188], some details of the 3D structure of the cylindrical assembly form are discussed.