Biochemical genetic evidence for a hybrid origin of spined loach, Cobitis taenia taenia, in Japan

Starch gel electrophoresis and isoelectric focusing were performed on sarcoplasmic proteins from three taxa of cobitid fish in Japan, Cobitis biwae , C. taenia striata and C. l. taenia . These taxa are hardly distinguishable from each other by external appearance or morphological characters. Electrophoretic patterns of sarcoplasmic proteins from white muscle suggested fixed allelic differences between C. biwae and C. t. striata at two protein-coding loci (parvalbumin and creatine kinase). The third taxon, C. t. taenia , showed composite banding patterns with respect to the above two proteins, suggesting C. t, taenia originated from hybridization between C. biwae and C, t. striata . Previously, C. t, taenia and C. t. striata were believed to have shared a common ancestor subsequent to their divergence from C. biwae .     

Detection of Specific RNAs by in situ Hybridization in Plant Protoplasts

Combined exposure of fixed tomato protoplasts to 0.2 N HCl atroom temperature, heating at 70?C in 2 ? SSC for 30 min, anddigestion with 10 µg/ml proteinase K allowed localizationof viroid RNA by in situ hybridization, without destructionof cellular structures. The technique also allowed localizationof viral RNA in tobacco protoplasts. ⁴Present address: National Institute of Animal Health, Tsukuba,Ibaraki, 305 Japan (Received March 1, 1989; Accepted February 21, 1990)     

Growth inhibition of Helicobacter pylori by apolyamine synthesis inhibitor, methylglyoxal bis(cyclopentylamidinohydrazone)

The anti-proliferative effect of methylglyoxal bis(cyclopentyl-amidino-hydrazone) (MGBCP), a multi-enzyme inhibitor of polyamine biosynthesis, on the growth of Helicobacter pylori was investigated. MGBCP inhibited the cell growth of H. pylori in a dose-dependent manner. The inhibition was partially reversed by the addition of spermidine. Synthesis of macromolecules, DNA, RNA and protein, was inhibited in the spermidine-depleted H. pylori cells. These findings suggest that MGBCP exhibits an anti-proliferative effect on H. pylori by suppression of macromolecule synthesis.     

Enantio-oligodeoxyribonucleotides

As a sugar-modified oligonucleotide, a hexamer of 9-(2-deoxy-beta-L-erythro-pentafuranosyl)-9H-purin-6-amine, [L-(dAp)5dA], was synthesized by triester method. The L-hexamer was resistant to bovine spleen phosphodiesterase. UV absorption studies indicated that L-hexamer formed a complex with poly U but not with poly dT at 0 degrees C. It was assumed that enantio-DNA's possese the ability to distinguish complementary RNA from DNA.     

Studies on the visual acuity of sheep using shape discrimination learning

Two experiments were conducted to determine the visual acuity of sheep. Three ewes were trained to discriminate between a Landolt ring and an ordinary ring of equal size associated with feed. The left and right positions of the 2 targets were shifted according to the Gellermann series. After the ewes were fully trained, their visual acuity was determined by changing the size of the rings or the distance from the target. The ewes were subjected daily to 1 or 2 sessions which consisted of 30 trials each. The criterion of successful discrimination was 2 (Exp. I) or 3 (Exp. II) consecutive sessions with more than 21 correct choices (P<0.05, Chi-square test). The best scores of visual acuity in the 3 ewes were 0.085, 0.095 and 0.19, respectively.     

Expression of mRNA of murine bone-related proteins in ectopic bone induced by murine bone morphogenetic protein-4

To determine whether a system of ectopic bone formation induced by osteosarcoma-derived bone-inducing substance (bone morphogenetic protein-4) can be used as a model of developing bone at the molecular level, we studied the expression of bone-related protein mRNAs in the process of ectopic bone formation using non-radioisotopic in situ hybridization. Osteonectin mRNA was detected in fibroblast-like cells, which are similar to periosteal cells from the early to middle stages of bone development. The proportion of osteonectin mRNA-expressing cells was greater than that of osteopontin mRNA-expressing cells in hypertrophic chondrocytes and osteoblast-like cells. In contrast, osteopontin mRNA was localized in a limited population of hypertrophic chondrocytes, a single layer of osteoblast-like cells adjacent to the bone trabeculae in the middle stage of bone formation, and in a limited subset of osteocytes in the late stage. A strong osteocalcin mRNA signal was detected in osteoblast-like cells from the middle to late stages and in a limited subset of osteocytes in the late stage of bone development. Since the sequential gene expression pattern of bone-related proteins in the present system is comparable to that in embryonic osteogenesis, this system may be useful as a model for studying gene expression in osteogenesis.     

Development of an enzyme-linked receptor assay (ERA) for hCG.

An enzyme-linked receptor assay (ERA) for hCG was developed using horseradish peroxidase. The 1,500 g pellets, interstitial cell fraction, and solubilized homogenate from the rat testis linked to tanned sheep red blood cells (SRBC) were used as the binding fractions for hCG. In these ERA systems, the limit of detection for hCG was 30 IU/l (3-12 mIU/tube), which was almost equal to that of radio receptor assay (RRA). The ERA using SRBC linked solubilized receptor fraction showed the most satisfactory result in accuracy, reproducibility and easiness.     

Influence of adjuvants on the antibody specificity to the Plasmodium falciparum major merozoite surface protein, gp195

The effect of adjuvants on the specificity of immune responses to the Plasmodium falciparum gp195 protein was investigated using adjuvant formulations based on synthetic muramyl dipeptide and monophosphoryl lipid A derivatives, in parallel with CFA and alum. Although these immunomodulators were as effective as CFA in inducing an antibody response to gp195, there were distinct differences in the recognition of B cell epitopes by these antibody populations. We have also demonstrated that MHC control of antibody specificity can be related to the adjuvant used for immunization. In general, the potency of adjuvants, their ability to induce antibodies of a particular specificity, or their ability to overcome MHC control of immune responsiveness varied independently. These findings suggest a critical role of adjuvants in the determination of the specificity of the immune response to protein Ag. Thus, the influence of adjuvants should be a major consideration in studies on immunologic recognition, as well as in the design of modern subunit vaccines.     

Turnover of enzymes of peroxisomal β-oxidation in rat liver

Male Wistar rats were given a diet containing 2% (w/w) di-(2-ethylhexyl)-phthalate (DEHP), a peroxisomal proliferator, for 4 weeks. The activities of enzymes of peroxisomal β-oxidation and of catalase were markedly increased by the DEHP administration. The time required to reach halfway to the maximal induction for enzymes of peroxisomal β-oxidation was 5–7 days, whereas that for catalase was 3 days. A separate DEHP group was placed on the control diet after 14 days of feeding with the DEHP diet. On the withdrawal of DEHP, activities of enzymes of the β-oxidation system and of catalase decreased to the control levels with a half-life of 2–3 days. Responses of some mitochondrial enzymes involved in fatty acid oxidation are also described.