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41.
A species of Daphnia, Daphnia curvirostris Eylmann, found in high mountain lakes and ponds in central Japan is described. Although there were some differences in the shape of the male rostrum and the chromosome number between European populations as described by Johnson (1952) and Trentini (1980), and Japanese ones collected from high mountain waters, Japanese specimens had many characteristics similar to the taxon D. curvirostris of Europe. 相似文献
42.
Ieharu Hishinuma Tetsuro Ishii Hiroyuki Watanabe Shiro Bannai 《In vitro cellular & developmental biology. Plant》1986,22(3):127-134
Summary Mouse lymphoma L1210 cells maintained in vitro at a high cell density for a certain time period adapted themselves to the
in vitro environment and were able to grow indefinitely. From these adapted cells, more than 30 clones were isolated. They
all had much higher activity to take up cystine than the original L1210 cells, supporting a previous view that the deficiency
of the cystine uptake limits the survival and growth of L1210 cells in vitro. The cystine uptake of one cloned cell line was
characterized. The enhanced uptake of cystine in these cells was mainly mediated by a Na+-independent, saturable system and was potently inhibited by glutamate and some other anionic amino acids, but less by aspartate.
Such activity of cystine uptake was not observed in the original L1210 cells. The results suggest that, upon adaptation in
vitro, L1210 cells acquire a new cystine transport activity necessary for survival and growth in vitro. 相似文献
43.
The eggs ofAlcichthys alcicornis were spawned in tank at the laboratory and reared for the studies of embryonic, larval and juvenile development. This species takes place entosomatic fertilization, and females spawn fertilized eggs after copulation. The eggs are demersal and adhesive, released as a clump forming a thin layer on the bottom of tank. There was no significant difference in embryonic development between this species and other oviparous teleostean species. Hatching occurred between 17 and 18 days after spawning at a mean water temperature of 8.5?C. The newly hatched larvae averaged 4.44 mm in body length (BL). The larvae attained to post-larval stage at 5.80 mm BL, and juvenile stage at 10.2 mm BL. A specific feature of the post-larvae was the appearance of three lines of the melanophores on the caudal part of fin fold. Carotenoid first appeared on the nape at 8.70 mm BL, heavily emerged beyond 12.9 mm BL, and turned up on the back also beyond 15.2 mm BL. Scales on the lateral line were completed by 18.5 mm BL. Three pairs of flaps were observed on the dorsal surface of the head at 37.0 mm BL. External features of adult specimens are almost completed by 52.0 mm BL, yet the tip of the first preopercular was not branched but remained simple. 相似文献
44.
45.
Satoh Hiroyuki; Okada Mitsumasa; Nakayama Katsumi; Murata Teruyo 《Plant & cell physiology》1985,26(5):931-940
Ribulose 5-phosphate (Ru5P) kinase (ATP:D-ribulose 5-phosphate1-phosphotrans- ferase; EC 2.7.1.19
[EC]
), an enzyme in the reductivepentose phosphate cycle, was purified from the green alga Bryopsismaxima and its activity and peptide composition were studied.The specific activity of purified Ru5P kinase was 20 µmoleRuBP formed (mg protein)1 min1 corresponding toa 490-fold purification from the supernatant of chloroplasts.The Km values of Ru5P kinase for ATP and Ru5P were 69 µMand 330 µM, respectively. The molecular size of Ru5P kinase was estimated as 90 kDa bygel filtration and that of its polypeptide as 41 kDa by SDS-polyacrylamidegel electrophoresis. A small portion of the Ru5P kinase wasfound in a large molecular state (500 kDa) which was consideredto be an inactive form of the enzyme. Ru5P kinase activity has been reported in the pyrenoid of Eremosphaeraviridis as well as ribulose 1,5-bisphosphate carboxylase-oxygenase(RuBisCO) and ribose 5-phosphate isomerase activity (Holdsworth1971). In Bryopsis maxima, among the pyrenoid polypeptides otherthan that of RuBisCO, we found a polypeptide of 42 kDa, similarto that of Ru5P kinase in molecular size and ratio to RuBisCO.A peptide map of the 42 kDa pyrenoid polypeptide, however, showedthat it differed from that of Ru5P kinase. In conclusion, Ru5Pkinase may be not involved in the pyrenoid of this alga. (Received January 19, 1985; Accepted May 15, 1985) 相似文献
46.
Manganese ion, like Mg2+, has been found to produce high biosynthetic activity of the unadenylylated form of glutamine synthetase obtained from Mycobacterium smegmatis, and the activity with each of these cations was decreased by the adenylylation of the enzyme. Further, the gamma-glutamyltransferase reaction was catalyzed in the presence of either Mn2+, Mg2+, or Co2+ with both unadenylylated and adenylylated enzyme; however, each of these divalent cation-dependent activities was also decreased by one order of magnitude by adenylylation of the enzyme. From studies of UV-difference spectra, it was found that the ability of M. smegmatis glutamine synthetase to assume a number of distinctly different configurations was the result of the varied response of the enzyme to different cations. When either Mn2+, Mg2+, Ca2+, or Co2+ was added to the relaxed (divalent cation-free) enzyme at saturated concentration, each produced a similar UV-difference spectrum of the enzyme, indicating that the conformational states induced by these cations are similar with respect to the polarity of the microenvironment surrounding the tyrosyl and tryptophanyl groups of the enzyme. The binding of Cd2+, Ni2+, or Zn2+ to the relaxed enzyme each produced a different shift in the UV-absorption spectrum of the enzyme, indicating different conformational states. The kinetics of the spectral change that occurred upon addition of Mn2+, Mg2+, or Co2+ to a relaxed enzyme preparation were determined. The first-order rate constants for the decrease in relaxed enzyme with Mn2+ and Mg2+ were 0.604 min-1 and 0.399 min-1, respectively, at 25 degrees C, pH 7.4. The spectral change with Co2+ was completed within the time of mixing (less than 4 s). For these three metal ions, the total spectral change as well as the time course of the change were the same for both the unadenylylated enzyme and the partially adenylylated enzyme. However, Hill coefficients obtained from spectrophotometric titration data for both Mn2+ and Mg2+ were decreased with adenylylated enzyme to compared with unadenylylated enzyme. These results suggest that covalently bound AMP on each subunit may be involved in subunit interactions within the dodecamer. Circular dichroism measurements also indicated that the various structural changes of the M. smegmatis glutamine synthetase were produced by the binding of the divalent cations. 相似文献
47.
Yohei Hashimoto Hiroyuki Ishizone Midori Moriyasu Kazuko Kawanishi Atsushi Kato Masaru Ogura 《Phytochemistry》1984,23(8):1807-1808
Three oleanane triterpenes were isolated from the roots of Periandra dulcis,and identified as 3β-hydroxy-25-al-olean-18-en-30-oic acid (periandric acid I), 3β-hydroxy-25-al-olean-12-en-30-oic acid (periandric acid II) and 3-oxo-25-hydroxy-olean-12-en-30-oic acid. The former two compounds (periandric acids I and II) were identical with the aglycones obtained by hydrolysis of periandrin I and II, respectively and the latter one was a new triterpene. 相似文献
48.
Summary Two new species of the Mermithidae (Nematoda) are described from the Japanese blackfly Simulium japonicum Matsumura. They are the first representatives of Gastromermis and Isomermis from Japan. Gastromermis mesostoma n. sp. is characterized by a terminal or near terminal mouth, 6 hypodermal cords and the absence of cloacal or vulvar lips.
Isomermis bipapillatus n. sp. is characterized by the small size of the spicules, their curved shape and by a pair of terminal hypodermal protuberances
in the tail.
This work was in part supported by a grant (No. 58570188) from the Japanese Ministry of Education, Science and Culture
This work was in part supported by a grant (No. 58570188) from the Japanese Ministry of Education, Science and Culture 相似文献
49.
Cycling of soil carbon in the first year after a clear-felling was compared with that before the felling in a Japanese red
pine forest in Hiroshima Prefecture, west Japan. The daily mean temperature at the soil surface in summer was increased after
the felling in comparison to that before felling, and the water content of both the A0 layer and the surface mineral soil was decreased due to the loss of the forest canopy. The rate of weight loss of the A0 layer was reduced after felling. However, accumulation of the A0 layer rapidly decreased because of the lack of litter supply to the forest floor. Low soil respiration after felling was
mainly caused by the cessation of root respiration. Analysis of annual soil carbon cycling was then conducted using a compartment
model. The relative decomposition rate of the A0 layer decreased whereas that of humus and dead roots in mineral soil increased to some extent after felling. The accumulation
of carbon in mineral soil, however, increased slightly due to the supply of humus from roots killed by the felling. 相似文献
50.
S Shimizu B Jha S Kagawa K Nakao K Yoshida S Wakabayashi A Matsuoka 《Endocrinologia japonica》1983,30(2):255-260
The culture for 7 days in medium with 5.5 mM glucose and 1 mM 2-deoxy-D-glucose enhanced the glucose sensitivity of neonatal rat B cells, and even stimulated their growth in vitro. Also, 2-deoxy-D-glucose supplementation maintained insulin release evoked by leucine and 2-ketoisocaproate from B cells at day 7 at levels several times higher than at day 1. The effect of leucine was greatly augmented by glutamine, whereas that of the 2-keto acid remained almost unchanged irrespective of the presence of glutamine. These results suggest an increase in oxidative catabolism of medium nutrients in B cells grown in medium with 2-deoxy-D-glucose for 7 days, and such metabolic changes may promote the growth of B cells in vitro. 相似文献