Extensive proliferation of oligodendrocyte precursors in the parenchyma of the embryonic chick central nervous system

The proliferation of oligodendrocyte lineage cells in the chick embryo central nervous system (CNS) was examined by double-immunolabeling with a lineage marker monoclonal antibody (mAb) O4 or mAb O1 and 5-bromo-3'-deoxyuridine (BrdU). In all regions examined, the first O4-positive (O4+) cells appeared in restricted regions of the ventricular zone (VZ), regarded as a site of oligodendrocyte origin. Within the O4+ focus, less than 20% of the O4+ cells incorporated BrdU. In contrast, O4+ cells in the parenchyma were mitotically active; for example, 40-50% of early O4+ cells were labeled with BrdU. Some of these were unipolar in shape, indicative of migratory precursor cells. The frequency of O4+/BrdU+ cell appearance decreased to less than 20% with further development. O1+ oligodendrocytes were largely mitotically inactive, with only approximately 5% of O1+ cells incorporating BrdU. These results clearly demonstrated that the VZ generates relatively few precursor cells and that these oligodendrocyte precursors actively generate their cohort in the parenchyma of the CNS.     

Regio-selective preparation of vinyl adenosine ester catalyzed by alkaline protease

The transesterification of divinyladipate with adenosine in DMF containing 20% (v/v) DMSO was catalyzed by Streptomyces sp. alkaline protease and esterification occurred exclusively at the 3-position of hydroxyl group of ribofuranose in adenosine to give 3-O-vinyladipoyl adenosine without other products.     

Onset of amnesia is delayed with a decrease in inhibition of protein synthesis during odor-taste associative learning in the terrestrial slug Limax valentianus

Slugs can retain odor-taste associative memory for several weeks, and this requires protein synthesis. We examined the dose-dependency of the onset time of amnesia caused by the protein synthesis inhibitor anisomycin, and showed that with reduced dose, the onset is shifted from 2 days to 3 days after conditioning; we could not shift the onset delay later than 3 days. Our results suggest that the mechanism underling memory retention is different in the period up to 3 days, versus the period later than 3 days. Our results also suggest that sustained inhibition of protein synthesis in the period from zero to 3 hr after conditioning is necessary to cause amnesia.     

Inhibition of osteoporosis due to restricted food intake by the fish oils DHA and EPA and perilla oil in the rat

Seven-week old female rats fed restricted foods including the fish oils Docosahesaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA) and perilla oil with food intake decreased by 50%, had increases of fracture force and bone mineral density (BMD) and decreases in levels of Deoxypiridinoline (Dpd) and Calcium (Ca) in the urine, compared with those of rats with osteoporosis due to restricted soy bean oil food intake. Therefore, the fish oils DHA and EPA and perilla oil depressed excretion of urinary Ca and inhibited osteoporosis due to restricted food intake.     

Running inhibits osteoporosis induced by protein-deficient (PD) food intake

Running at 0.7 km/h for 10 min every day inhibited development of osteoporosis caused by protein deficient (PD) food intake. Urine alkaline phosphatase (ALP), a marker of bone formation osteoporosis, was not elevated in rats fed PD, when the osteoporosis was inhibited by running. Estrogen supplementation increased bone-breaking energy (BBE), but did not increase bone mineral density (BMD), and did not decrease urinary ALP levels.     

Histochemical analysis of glycoconjugates in the eccrine glands of the raccoon digital pads

The distribution and selectivity of complex carbohydrates in the eccrine glands of the digital pads in the North American raccoon (Procyon lotor) were studied using light and electron microscopic histochemical methods, particularly lectin histochemistry. In the eccrine glands, the dark cells exhibited neutral and acidic glycoconjugates with different saccharide residues (alpha-L-fucose, beta-D-galactose, beta-N-acetyl-D-glucosamine and N-acetyl-neuraminic acid); the clear cells contained numerous glycogen particles and showed a distinct reaction of alpha-L-fucose. The presence of complex carbohydrates with various terminal sugars was evident in the excretory duct cells. In addition, beta-D-galactose and N-acetyl-neuraminic acid residues were mainly observed in the luminal secretion. The glycoconjugates produced by the eccrine glands of the raccoon digital pads may protect the epidermis against physical damage or microbial contamination. In this way, the normal functioning of the sensory apparatus of the foot pads is ensured.     

Genetic divergence between and within two color morphotypes of <Emphasis Type="Italic">Parapercis sexfasciata</Emphasis> (Perciformes: Pinguipedidae) from Tosa Bay,southern Japan

The anterior half of the mitochondrial DNA control region (mtCR) sequence (ca. 400 base pairs) was compared between two color morphotypes (A, B) of Parapercis sexfasciata from Tosa Bay, southern Japan, using 16 and 21 specimens, respectively. Intramorphotypic mtCR divergences were only 0.0–0.5% and 1.0–2.5% for morphotypes A and B, respectively. In contrast, intermorphotypic mtCR divergence was much greater, 12.7–14.0%. Furthermore, phylogenetic analysis using a neighbor-joining algorithm, with P. multifasciata as an outgroup, showed that each morphotype was reciprocally monophyletic. These results and the distinct coloration and overlapping distribution indicate that the two color morphotypes of P. sexfasciata represent two distinct species. Mismatch distribution analysis suggested that both morphotypes had undergone population expansion; however, estimates of initial population sizes and mutational timescales suggested that morphotype B comprises historically larger and older populations than morphotype A.     

A new species of <Emphasis Type="Italic">Sebastes</Emphasis> (Scorpaeniformes: Scorpaenidae) from the Pacific coast of southern Japan

A new rockfish, Sebastes kiyomatsui, is described on the basis of 13 specimens from the Pacific coast of southern Japan. The new species resembles S. scythropus in having two sharp preorbital and robust preocular, supraocular, and postocular spines, but differs from the latter in having a black blotch on the opercle not extending to the subopercle, indistinct crimson marks on the body, blackish region of the oral cavity reaching to the prevomer and palatine, blackish tongue, a small ridge on the upper edge of the lachrymal, somewhat larger orbit, somewhat lower caudal peduncle, and seven lower unbranched pectoral fin rays. Sebastes kiyomatsui is a deep water (ca. 250m) inhabitant.     

Phylogenetic relationships of the stromateoid fishes (Perciformes)

The phylogenetic relationships of all 16 genera (plus Psenes pellucidus) of the suborder Stromateoidei were estimated cladistically based on 43 osteological, myological, and external characters. Thirty equally parsimonious trees were obtained. Based on the strict consensus tree, Centrolophidae was nonmonophyletic, Psenopsis being placed as a sister group of a clade comprising Amarsipus, Ariomma, nomeids, Tetragonurus, and stromateids. Schedophilus formed a sister group relationship with Seriolella. The relationships among the Centrolophus, Hyperoglyphe, Icichthys, Tubbia, Schedophilus+Seriolella clade, and Psenopsis+Amarsipus+Ariomma+nomeids+Tetragonurus+stromateids clade were unresolved. Amarsipus, which is unique within the suborder in lacking a pharyngeal sac, was nested within the stromateoid clade, being a sister group of the clade including Ariomma, nomeids, Tetragonurus, and stromateids. The absence of a pharyngeal sac in Amarsipus was interpreted as a reversal, its presence in the Stromateoidei therefore being considered as a synapomorphy. Ariomma was placed as the sister group of a clade comprising nomeids, Tetragonurus, and stromateids. Monophyly of the Nomeidae and Stromateidae were supported by 2 and 11 synapomorphies, respectively.