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991.
Yomiko Kegoya Masato Setoguchi Keiichi Yokohiki Chitoshi Hatanaka 《Bioscience, biotechnology, and biochemistry》2013,77(4):1055-1060
An exopolygalacturonate lyase (exo-PGL) was rapidly purified from the cells of E. carotovora subsp. carotovora with a modified cross-linked pectate (mdCLPA); the material CLPA was partially degraded by an endopolygalacturonase to increase its adsorption capacity, followed by reduction with sodium borohydride. The Erwinia strain used here produced no pectolytic enzyme other than the exo-PGL under the present culture conditions. Since the mdCLPA was scarcely affected by the exo-PGL, the adsorbent can be repeatedly used for this enzyme purification with no risk of decomposition. The yield of the purified enzyme, which gave a single protein band on polyacryl-amide gel electrophoresis, was about 43%. The apparent molecular weight was about 76,000. 相似文献
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993.
Dan Eshel Chikako Shingyoji Kenjiro Yoshimura Ian R. Gibbons Keiichi Takahashi 《Experimental cell research》1992,202(2):552-555
We have studied the phase component of flagellar beating by holding the head of a sea urchin sperm in the tip of a sinusoidally vibrating micropipet and then abruptly displacing the pipet laterally at a speed of 2.5 microns/ms for various durations. This rapid displacement of the pipet delayed the initiation of the next bend for as long as the displacement continued, up to a duration of 1 beat cycle, corresponding to a delay of 0.5 beat cycle. At the end of this displacement, the movement of the pipet was stopped completely without resumption of the initial vibration. Analysis of the flagellar waveform showed that immediately when the pipet was stopped, the flagellum started to beat by spontaneously initiating the bend that had been delayed. The flagellum then continued steady-state beating, with normal waveform and a new phase that was independent of the original phase of beating. These data suggest that the information on the phase of beating is located only at the basal end of the flagellum, and not in oscillators distributed along the axoneme. After this information has been lost, the flagellum can resume beating at any arbitrary phase relative to its original phase. 相似文献
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995.
Bert Hölldobler Jacqueline M. Palmer Keiichi Masuko William L. Brown Jr. 《Zoomorphology》1989,108(5):255-261
Summary This paper reports the results of the first detailed study of the morphology of exocrine glands in two species of the ant subfamily Leptanillinae. Workers of Leptanilla escheri and L. japonica possess a large, unpaired sternal gland in the VIIth abdominal sternite, and an hypertrophied poison gland which is surrounded by a massive muscle layer. The sternal gland is absent in the queen of L. japonica, and the poison gland is highly degenerated. The queen is, however, endowed with a series of large, paired, intersegmental tergal and sternal glands, which occur between the IVth through the VIIth segments. The queen also posseses large spiracular plate glands. 相似文献
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Takuya Chiba Junjie Yao Yoshikazu Higami Isao Shimokawa Masanori Hosokawa Keiichi Higuchi 《Mammalian genome》2007,18(2):105-112
Senescence-accelerated mouse (SAM) strains constitute a model of accelerated senescence coupled with a short lifespan and
the early development of various age-related disorders. To identify differential gene expression in testes between senescence-accelerated
SAMP1 and control SAMR1 mice, we performed suppression subtractive hybridization. We observed that the expression of three
genes related to cell proliferation (myosin regulatory light chain B, aldolase 1A isoform, and cytochrome c oxidase subunit
VIc) were upregulated and four genes implicated in spermatogenesis were downregulated in SAMP1 mice. Asb-8, a member of ankyrin
repeat-containing proteins, was abundantly expressed in the testes and downregulated in SAMP1. The other three downregulated
genes (germ cell-specific gene 1, T-complex polypeptide 1b, and activator of cAMP responsive element modulator in testis)
have been reported to regulate late-stage spermatogenesis. These gene expression profiles might explain the findings of early
testicular maturation and rapid decline in the ability to produce spermatozoa with advancing age in SAMP1 mice. 相似文献
1000.