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2.
Kei Watanabe Kenta Wada Tomoko Ohashi Saki Okubo Kensuke Takekuma Ryoichi Hashizume Jun-Ichi Hayashi Tadao Serikawa Takashi Kuramoto Yoshiaki Kikkawa 《PloS one》2012,7(11)
We discovered a new cataract mutation, kfrs4, in the Kyoto Fancy Rat Stock (KFRS) background. Within 1 month of birth, all kfrs4/kfrs4 homozygotes developed cataracts, with severe opacity in the nuclei of the lens. In contrast, no opacity was observed in the kfrs4/+ heterozygotes. We continued to observe these rats until they reached 1 year of age and found that cataractogenesis did not occur in kfrs4/+ rats. To define the histological defects in the lenses of kfrs4 rats, sections of the eyes of these rats were prepared. Although the lenses of kfrs4/kfrs4 homozygotes showed severely disorganised fibres and vacuolation, the lenses of kfrs4/+ heterozygotes appeared normal and similar to those of wild-type rats. We used positional cloning to identify the kfrs4 mutation. The mutation was mapped to an approximately 9.7-Mb region on chromosome 7, which contains the Mip gene. This gene is responsible for a dominant form of cataract in humans and mice. Sequence analysis of the mutant-derived Mip gene identified a 5-bp insertion. This insertion is predicted to inactivate the MIP protein, as it produces a frameshift that results in the synthesis of 6 novel amino acid residues and a truncated protein that lacks 136 amino acids in the C-terminal region, and no MIP immunoreactivity was observed in the lens fibre cells of kfrs4/kfrs4 homozygous rats using an antibody that recognises the C- and N-terminus of MIP. In addition, the kfrs4/+ heterozygotes showed reduced expression of Mip mRNA and MIP protein and the kfrs4/kfrs4 homozygotes showed no expression in the lens. These results indicate that the kfrs4 mutation conveys a loss-of-function, which leads to functional inactivation though the degradation of Mip mRNA by an mRNA decay mechanism. Therefore, the kfrs4 rat represents the first characterised rat model with a recessive mutation in the Mip gene. 相似文献
3.
Hydrogen peroxide was formed in isolated cell walls from Marchantiapolymorpha L. in the presence of MnCl2 by either NADH or NADPHoxidation. This reaction was stimulated by phenols such as 2,4-dichlorophenolor p-coumarate, suggesting a reaction similar to that proposedfor the last step of lignification in higher plant cells, althoughbryophytes have been reported to be devoid of lignin. (Received June 16, 1987; Accepted March 3, 1987) 相似文献
4.
Takashi Saito Kensuke Futatsugi Daisuke Miki Hiroshi Suzuki Kiyoshi Yasukawa 《Biotechnology Techniques》1992,6(4):365-370
Summary Murine interleukin-6 (mIL-6) was expressed inEscherichia coli as human growth hormone (hGH) fusion protein. The products were cleaved by thrombin to liberate mIL-6. Monoclonal and polyclonal
antibodies specific to mIL-6 were prepared by immunizing rats with mIL-6 thus obtained. ELISA for the quantitation of mIL-6
was also established, which could detect mIL-6 in a quantity as low as 2 ng/ml. 相似文献
5.
Yuichiro Arai Se KyungKim Hiroyasu Kinemuchi Takeshi Tadano Shinetsu Satoh Nobunori Satoh Katsuyuki Oyama Kensuke Kisara 《Neurochemistry international》1990,17(4):587-592
The present study was carried out mainly to clarify whether the two amphetamine metabolites, p-hydroxyamphetamine (P-OHA) and p-hydroxynorephedrine (p-OHN) are taken up by mouse brain 5-hydroxytryptamine (5-HT) nerve terminals to inhibit type A monoamine oxidase (MAO-A) and then potentiate the abnormal behavior, head-twitch. Of the two metabolites, only intracerebroventricular p-OHA, at 80 μg/mouse, sufficient to cause a head-twitch response (HTR), appreciably inhibited MAO-A activity without affecting MAO-B activity in homogenates of the mouse striatum, hypothalamus and the rest of the forebrain; and p-OHN did not inhibit either type of MAO at the dose tested. Estimation of intra- and extrasynaptosomal MAO-A activity showed that both metabolites significantly inhibited only the intrasynaptosomal deamination of 5-HT by MAO-A with p-OHA being more potent. Taken together with our previous findings, these present results clearly indicate that p-OHA may accumulate in the 5-HT nerve terminals through the uptake system, and concomitantly inhibit MAO-A activity. These actions of p-OHA may increase intraneuronal 5-HT levels and then potentiate 5-HT release to cause interaction with the post-synaptic 5-HT receptors. 相似文献
6.
Kivoshi Ohkawa Tae Hirakawa-Sakurai Kensuke Joh Tadashi Asakura Koji Takada Makoto Matsuda 《Neurochemical research》1994,19(10):1231-1235
Murine polyclonal antibody against purified bovine brain pyridoxal kinase (EC 2.7.1.35) was generated and showed cross-reactivity with rabbit brain pyridoxal kinase. This antibody was used to immunohistochemically examine the distribution of pyridoxal kinase in the rabbit brain. The cytoplasm of neuronal cells and neuroglial cells in the cerebral cortex, hippocampal region, brain nuclei and cerebellar cortex showed positive staining with various degrees of intensity. The neuronal cells and surrounding fibers in some brain nuclei, such as the area tegmentalis ventralis or the substantia nigra, showed intense staining. The neuronal cells of the hippocampal region showed somewhat weak reactivity, but some with intense reactivity were found sparsely distributed and positive staining fiber networks of a very low density were also observed. 相似文献
7.
Kensuke Nakanishi Nao Hasegawa Koichi Takeo Keisuke Nakajima Nobuaki Furuno Ichiro Tazawa 《Development, growth & differentiation》2023,65(2):100-108
Some frog species have a unique skeletal element, referred to as the intercalary element (IE), in the joints between the terminal and subterminal phalanges of all digits. IEs are composed of cartilage or connective tissue and have a markedly differ shape than the phalanges. IEs are highly related to the arboreal lifestyle and toe pads. The IE is found only in neobatrachian frogs among anurans, suggesting that it is a novelty of Neobatrachia. IEs are widely distributed among multiple neobatrachian lineages and are found in the suborders Hyloides and Ranoides (the two major clades in Neobatrachia). However, it is unclear whether the IEs found in multiple linages resulted from convergent evolution. Therefore, in this study, we aimed to examine how similar or different the developmental trajectories of the IEs are between Hyloides and Ranoides. To that end, we compared the osteological and histological developmental processes of the IEs of the hyloid frog Dryophytes japonicus and the ranoid frog Zhangixalus schlegelii. Both species shared the same IE-initiation site and level of tissue differentiation around the IE when it began to form in tadpoles, although the IE developments initiated at different stages which were determined by external criteria. These results suggest that similar mechanisms drive IE formation in the digits of both species, supporting the hypothesis that the IEs did not evolve convergently. 相似文献
8.
Intramolecular disulfide linked alphabeta and alphaalpha in oxidized tropomyosin: separation, identification, and process of formation 总被引:1,自引:0,他引:1
N Ookubo 《Journal of biochemistry》1977,81(4):923-931
The oxidation of rabbit skeletal tropomyosin (TM) by repeated cycles of freezing and melting in 0.3 mM Na bicarbonate was studied by electrophoresis and column chromatography. The oxidized TM showed two bands at ca. 70,000 daltons on sodium dodecyl sulfate (SDS)-polyacrylamide gels. Each band component was separated into disulfide-linked alphabeta and alphaalpha by carboxymethyl cellulose (CMC) column chromatography in urea. Oxidized TM before fractionation, as well as the alphabeta and alphaalpha components, was found to have a molecular weight of about 80,000 daltons, indicating the disulfide bonds to be primarily intramolecular. Oxidation of dilute TM in 1 M NaCl by exposure to air also produced disulfide-linked alphabeta. Partially oxidized TM was found to separate into beta, alphabeta, alpha, and alphaalpha on CMC chromatography, and these were eluted with a linear gradient of NaCl at molarities of ca. 0.09, 0.11, 0.12, and 0.14 M, respectively. The oxidation process was investigated by CMC chromatography, and a possible mechanism is presented. The alphabeta and alphaalpha components may exist as dominant component in TM in vitro rather than as a random mixture of two subunits. A splitting of the electrophoretic band of the alpha subunit into a doublet was observed. 相似文献
9.
Effect of Chlorine Substitution on the Biodegradability of Polychlorinated Biphenyls 总被引:29,自引:22,他引:7
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Thirty-one isomers of polychlorinated biphenyl (PCB) were examined for biodegradability by two species of Alcaligenes and Acinetobacter. The following relationships between chlorine substitution and biodegradability of PCBs were observed. (i) Degradation decreased as chlorine substitution increased. PCB isomers containing more than four chlorines were less susceptible to degradation. (ii) PCBs containing two chlorines on either the ortho position of a single ring (i.e., 2,6-) or on both rings (i.e., 2,2′-) showed very poor degradability. (iii) PCBs containing all chlorine atoms on only a single ring were generally degraded faster than when the same number of chlorines were substituted on both rings. (iv) Preferential ring fission of the molecules occurred with nonchlorinated or lesser chlorinated rings. (v) The formation and accumulation of a yellow intermediate was always observed in 4′-chloro-substituted PCBs. (vi) Significant differences between the two organisms with respect to degradability were not observed except for 2,4,6-trichlorobiphenyl. 相似文献
10.
The titration curve of ultrasonic absorption at 2.82 MHz in aqueous solutions of lysozyme measured by Zana and Lang [J. Phys. Chem., 74 , 2734 (1970)] is theoretically analyzed. The maxima at pH 3 and pH 11 are describable with proton-transfer reactions of dissociable carboxyl and amino groups by assuming that volume changes due to the reactions are 2.3 and 5.2 cm3/mole, respectively, which are appreciably smaller than those of simple amino acids. The remaining, pH-independent excess absorption over solvent is measured at frequencies ranging from 3 to 150 MHz. The absorption is ascribed to the internal loss of protein. The complex compressibility β′p ? iβ″p of lysozyme molecule is evaluated as β′p = 7.2 × 10?12 cm2/dyne and β″P = 4.3 × 10?14 cm2/dyne from the increments over solvent in absorption as well as in sound velocity. 相似文献