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191.
Aberrant chloroplasts in transgenic rice plants expressing a high level of maize NADP-dependent malic enzyme 总被引:16,自引:0,他引:16
NADP-dependent malic enzyme (NADP-ME) is a major decarboxylating enzyme in NADP-ME-type C4 species such as maize and Flaveria. In this study, chloroplastic NADP-ME was transferred to rice (Oryza sativa L.) using a chimeric gene composed of maize NADP-ME cDNA under the control of rice light-harvesting chlorophyll-a/b-binding protein (Cab) promoter. There was a 20- to 70-fold increase in the NADP-ME activity in leaves of transgenic rice
compared to that in wild-type rice plants. Immunocytochemical studies by electron microscopy showed that maize NADP-ME was
mostly localized in chloroplasts in transgenic rice plants, and that the chloroplasts were agranal without thylakoid stacking.
Chlorophyll content and photosystem II activity were inversely correlated with the level of NADP-ME activity. These results
suggest that aberrant chloroplasts in transgenic plants may be caused by excessive NADP-ME activity. Based on these results
and the known fact that only bundle sheath cells of NADP-ME species, among all three C4 subgroups, have agranal chloroplasts, we postulate that a high level of chloroplastic NADP-ME activity could strongly affect
the development of chloroplasts.
Received: 27 January 1999 / Accepted: 20 January 2000 相似文献
192.
193.
cDNA cloning, gene expression and subcellular localization of anthocyanin 5-aromatic acyltransferase from
Gentiana triflora 总被引:5,自引:3,他引:2
Hiroyuki Fujiwara Yoshikazu Tanaka Keiko Yonekura-Sakakibara Masako Fukuchi-Mizutani Masahiro Nakao Yuko Fukui Masaatsu Yamaguchi Toshihiko Ashikari Takaaki Kusumi 《The Plant journal : for cell and molecular biology》1998,16(4):421-431
Acylation of anthocyanins with hydroxycinnamic acid derivatives is one of the most important and less understood modification reactions during anthocyanin biosynthesis. Anthocyanin aromatic acyltransferase catalyses the transfer of hydroxycinnamic acid moieties from their CoA esters to the glycosyl groups of anthocyanins. A full-length cDNA encoding the anthocyanin 5-aromatic acyltransferase (5AT) ( EC 2.3.1.153 ) that acylates the glucose bound at the 5-position of anthocyanidin 3,5-diglucoside was isolated from petals of Gentiana triflora on the basis of the amino acid sequence of the purified enzyme. The isolated full-length cDNA had an open reading frame of 469 amino acids and the calculated molecular weight was 52 736. The deduced amino acid sequence contains consensus motifs that are conserved among the putative acyl CoA-mediated acyltransferases, and this indicates that 5AT is a member of a proposed superfamily of multifunctional acyltransferases ( St-Pierre et al . (1998 ) Plant J. 14, 703–713). The cDNA was expressed in Escherichia coli and yeast, and confirmed to encode 5AT. The enzymatic characteristics of the recombinant 5AT were consistent with those of the native gentian 5AT. Immunoblot analysis using specific antibodies to 5AT showed that the 5AT protein is present in petals, but not in sepals, stems or leaves of G. triflora . RNA blot analysis showed that the 5AT gene is expressed only in petals and that its expression is temporally regulated during flower development coordinately with other anthocyanin biosynthetic genes. Immunohistochemical analysis demonstrated that the 5AT protein is specifically expressed in the outer epidermal cells of gentian petals and that it is localized mainly in the cytosol. 相似文献
194.
The exact timing ofAnguilla japonica spawning was determined from analyses of daily otolith increments in leptocephali collected near a spawning area west of
the Mariana Islands on July 1–18, 1991. The birth dates of the 54 leptocephali examined (10.2 to 30.5 mm in total length)
ranged from May 22 to June 24, 1991, the individuals clearly comprising two age groups, May-born fish (mode May 28) and June-born
fish (mode June 21). The data showed thatA. japonica spawns intermittently during the spawning season, with fixed synchronized timing. Each group of leptocephali collected along
three different north-south transects (131°, 134° and 137°E between 10° and 22°N) comprised both May-born and June-born fish.
The latter were dominant along the easternmost and middle transects, whereas the May-born fish were more abundant along the
westernmost transect. The modal ages of the June-born and May-born fish collected along 137°E on July 1–3 were 13 d and 35
d, respectively, while those of the two age groups collected along 134°E on July 17 and 18 were 28 d and 50 d, respectively.
These data show that the interval between the sampling dates for the two transects (ca. 15 d) corresponded closely to the
differences in modal ages of specimens from the two transects (15 d) for both the May- and June-born fish, and further, that
the difference in modal age between the two age groups (22 d) was the same at both transects. A similar correspondence in
total length was also observed between the two age groups at the above two transects. The findings clearly demonstrated parallel
westward transport by the North Equatorial Current for both the May- and June-born eel leptocephali, which originated from
a spawning area estimated as being between 141° and 143°E. 相似文献
195.
Yumi Moriwake Yoshiyuki Tohno Setsuko Tohno Takeshi Minami Masako Utsumi Fumio Nishiwaki Masa-oki Yamada Hiroshi Yamamoto Yuko Okazaki Tadashi Fujii Yoshinori Takakura 《Biological trace element research》1998,64(1-3):229-235
The relative contents (RCs) of elements in the human menisci from 23 subjects in the age range between 65 and 93 yr were analyzed
by inductively coupled plasma atomic emission spectrometry. The RCs of sulfur, calcium, and phosphorus in menisci increased
progressively until the 80s, being the highest in the 80s, and thereafter decreased. The RCs of magnesium in menisci increased
progressively until the 90s. Regarding the medial and lateral menisci, higher RCs of magnesium and iron, and a lower RC of
phosphorus were found in lateral menisci in comparison with those in medial menisci.
There were sexual differences in the RCs of calcium and phosphorus of medial and lateral menisci. The RCs of calcium and phosphorus
were about 50% higher in women’s menisci than in men’s. Histological examinations showed that structureless mucoid masses
were observed in the menisci, with very high RCs of calcium and phosphorus being detected. 相似文献
196.
197.
198.
Masako Takashima Ri-ichiroh Manabe Wataru Iwasaki Akira Ohyama Moriya Ohkuma Takashi Sugita 《PloS one》2015,10(8)
The order Trichosporonales (Tremellomycotina, Basidiomycota) includes various species that have clinical, agricultural and biotechnological value. Thus, understanding why and how evolutionary diversification occurred within this order is extremely important. This study clarified the phylogenetic relationships among Tricosporonales species. To select genes suitable for phylogenetic analysis, we determined the draft genomes of 17 Trichosporonales species and extracted 30 protein-coding DNA sequences (CDSs) from genomic data. The CDS regions of Trichosporon asahii and T. faecale were identified by referring to mRNA sequence data since the intron positions of the respective genes differed from those of Cryptococcus neoformans (outgroup) and are not conserved within this order. A multiple alignment of the respective gene was first constructed using the CDSs of T. asahii, T. faecale and C. neoformans, and those of other species were added and aligned based on codons. The phylogenetic trees were constructed based on each gene and a concatenated alignment. Resolution of the maximum-likelihood trees estimated from the concatenated dataset based on both nucleotide (72,531) and amino acid (24,173) sequences were greater than in previous reports. In addition, we found that several genes, such as phosphatidylinositol 3-kinase TOR1 and glutamate synthase (NADH), had good resolution in this group (even when used alone). Our study proposes a set of genes suitable for constructing a phylogenetic tree with high resolution to examine evolutionary diversification in Trichosporonales. These can also be used for epidemiological and biogeographical studies, and may also serve as the basis for a comprehensive reclassification of pleomorphic fungi. 相似文献
199.
Kristina Kirschner Shamith A. Samarajiwa Jonathan M. Cairns Suraj Menon Pedro A. Pérez-Mancera Kosuke Tomimatsu Camino Bermejo-Rodriguez Yoko Ito Tamir Chandra Masako Narita Scott K. Lyons Andy G. Lynch Hiroshi Kimura Tetsuya Ohbayashi Simon Tavaré Masashi Narita 《PLoS genetics》2015,11(3)
The downstream functions of the DNA binding tumor suppressor p53 vary depending on the cellular context, and persistent p53 activation has recently been implicated in tumor suppression and senescence. However, genome-wide information about p53-target gene regulation has been derived mostly from acute genotoxic conditions. Using ChIP-seq and expression data, we have found distinct p53 binding profiles between acutely activated (through DNA damage) and chronically activated (in senescent or pro-apoptotic conditions) p53. Compared to the classical ‘acute’ p53 binding profile, ‘chronic’ p53 peaks were closely associated with CpG-islands. Furthermore, the chronic CpG-island binding of p53 conferred distinct expression patterns between senescent and pro-apoptotic conditions. Using the p53 targets seen in the chronic conditions together with external high-throughput datasets, we have built p53 networks that revealed extensive self-regulatory ‘p53 hubs’ where p53 and many p53 targets can physically interact with each other. Integrating these results with public clinical datasets identified the cancer-associated lipogenic enzyme, SCD, which we found to be directly repressed by p53 through the CpG-island promoter, providing a mechanistic link between p53 and the ‘lipogenic phenotype’, a hallmark of cancer. Our data reveal distinct phenotype associations of chronic p53 targets that underlie specific gene regulatory mechanisms. 相似文献
200.