共查询到20条相似文献,搜索用时 625 毫秒
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Molina A Corta A Martin RS Alvarez M Burzio LO Krauskopf M Vera MI 《Biochemical and biophysical research communications》2002,295(3):582-586
The seasonal acclimatization of the carp fish demands physiological compensatory responses. The process involves profound nucleolar adjustments and remarkable changes in rRNA synthesis, which affect ribosomal biogenesis. We have documented that protein kinase CK2, whose activity is related to ribosomal protein L41 and the regulation of rRNA synthesis, was expressed in notably higher amounts in summer-acclimatized carp compared to the cold-season adapted fish. Thus, we approached the study of the functional genomics of carp L41 protein. We report the first cloning of a fish L41 gene encoding the highly conserved 25 amino acids, including approximately 1700 bp regulatory upstream region and the 3(') polyadenylation signal, plus the isolation and characterization of two different L41 cDNAs. We found a clear differential expression of L41, which follows the same pattern as protein kinase CK2beta that transcribes at higher levels in the summer-acclimatized carp than it does in the winter-adapted fish. 相似文献
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Cyprinus carpio skeletal muscle kallikrein was isolated to apparent homogeneity, and a polyclonal antiserum against the purified protein was generated. Glandular kallikrein expression and tissue distribution were assessed using both Western blots and immunohistochemistry. A 39-kDa protein was detected in skeletal muscle, the gill, kidney, and pituitary gland, where an additional 72-kDa immunoreactive band was observed. Immunohistochemistry revealed immunoreactive kallikrein in the intermuscle tissue, epithelial gill cells, apical portion of distal and proximal tubular cells in the kidney, mucus and epithelial cells of the skin, intestinal tube, and prolactin-producing cells of the pituitary gland. In addition, the effect of 17beta-estradiol on kallikrein expression was analyzed in three different tissues of winter- and summer-acclimatized male carps. A 2.5-fold (p<0.05) increase in kallikrein immunoreactivity due to estrogen treatment was observed in winter-acclimatized carp muscle, but not in summer-acclimatized fish. In contrast, the gill responded differently, since a 2-fold (p<0.05) increase was found only in summer-acclimatized carps. Kallikrein immunoreactivity in the kidney increased both in summer- (2.5 fold) and in winter-acclimatized carps (1.5 fold). The signals obtained demonstrate the existence of tissue-specific variable responses to estrogen treatment in vivo, between winter and summer-acclimatized carp. 相似文献
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本研究分别以β-actin、18S rRNA和GAPDH为内参基因,采用实时荧光定量PCR对草鱼早期发育时期肌球蛋白重链(myosin heavy light,MYH)基因的mRNA表达量进行分析,并比较不同内参基因对MYH基因mRNA表达水平检测结果的准确性.研究结果表明,以β-actin和GAPDH作为内参,MYH基因mRNA表达水平完全一致,其表达量从原肠到仔鱼阶段逐次递增,仔鱼与原肠期阶段相比表达量差异显著;当采用18S rRNA作为内参时,MYH基因mRNA在发育阶段的表达量呈不稳定状态.因此,β-actin和GAPDH均可作为内参基因,用于草鱼早期发育中MYH基因mRNA的相对定量研究:而18S rRNA作为内参时,可能会对检测结果造成偏差.本研究不仅准确的揭示了草鱼MYH基因mRNA的表达特征,并且为荧光定量PCR技术在鱼类基因表达研究方面提供了有价值的参考. 相似文献
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Vornanen M Haverinen J 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2011,181(7):917-926
Seasonal changes in the activity of glycogen phosphorylase (GP), a rate-limiting enzyme of glycogen degradation, were examined
in an anoxia-tolerant fish species, the crucian carp (Carassius carassius L.). In muscle and brain, the activity of GP remained constant throughout the year when tested at 25°C. In contrast, the
activities of liver and heart GP displayed striking increases in summer. When seasonal temperature changes are taken into
account, the activity of GP during the anoxic mid-winter is only 4–6% of its summer time activity in the muscle, heart and
liver, and 13% in brain. In winter-acclimatized fish, experimental anoxia (1–6 weeks) caused sustained depression of the GP
activity in heart and gills. In liver and muscle, a transient depression of GP activity occurred during the first week of
anoxia but later GP activity recovered back to the normoxic level. GP of the brain was completely resistant to anoxia. In
all studied tissues, the constitutive activity of GP is more than sufficient to degrade glycogen deposits during winter anoxia
without anoxia-induced activation of GP. The seemingly paradoxical summer-time increase in the activity of liver and heart
GP could be related to active life-style of the summer-acclimatized fish (growth, reproduction), the increased demand of energy
and molecular precursors of anabolic metabolism being satisfied by preferential degradation of glycogen. The high glycogen
content of winter-acclimatized crucian carp is not associated with the elevated GP activity or anoxic activation of GP. 相似文献
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A. Pedrosa D. Schweizer M. Guerra 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):361-367
Citrus sinensis chromosomes, although small in size, present a remarkable differentiation of bands with the fluorochromes CMA and DAPI. These
bands suggest that some heteromorphisms are fixed in this species. To investigate the extension of these heteromorphisms,
ten cultivars of C. sinenesis were analysed with CMA/DAPI staining and, in some of them, the 18S–5.8S–25S rRNA and 5S rRNA genes were located by in situ
hybridization. CMA/DAPI staining showed exactly the same CMA+/DAPI− banding pattern for all cultivars. In situ hybridization revealed three 18S–5.8S–25S rRNA gene sites, two proximally located
on two similar chromosomes and one terminally located on a third non-related chromosome. Two 5S rRNA gene sites were observed
in this species, with one located proximal to the telomeric 18S–5.8S–25S rDNA site. Both cytological approaches revealed an
invariable, heterozygotic karyotype among sweet orange cultivars. Based on these data, the putative hybrid origin of the species
is discussed.
Received: 9 April 1999 / Accepted: 22 June 1999 相似文献
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T. Schmidt T. Schwarzacher J. S. Heslop-Harrison 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(6-7):629-636
A digoxigenin-labelled 5S rDNA probe (pTa-794) and a rhodamine-labelled 18S-5.8S-25S rDNA probe (pTa71) were used for double-target in-situ hybridization to root-tip metaphase, prophase and interphase chromosomes of cultivated beet,Beta vulgaris L. After in-situ hybridization with the 18S-5.8S-25S rDNA probe, one major pair of sites was detected which corresponded to the secondary constriction at the end of the short arm of chromosome 1. The two rDNA chromosomes were often associated and the loci only contracted in late metaphase. In the majority of the metaphase plates analyzed, we found a single additional minor hybridization site with pTa71. One pair of 5S rRNA gene clusters was localized near the centromere on the short arm of one of the three largest chromosomes which does not carry the 18S-5.8S-25S genes. Because of the difficulties in distinguishing the very similarly-sizedB. vulgaris chromosomes in metaphase preparations, the 5S and the 18S-5.8S-25S rRNA genes can be used as markers for chromosome identification. TwoXbaI fragments (pXV1 and pXV2), comprising the 5S ribosomal RNA gene and the adjacent intergenic spacer, were isolated. The two 5S rDNA repeats were 349 bp and 351 bp long, showing considerable sequence variation in the intergenic spacer. The use of fluorescent in-situ hybridization, complemented by molecular data, for gene mapping and for integrating genetic and physical maps of beet species is discussed. 相似文献
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We investigated the influence of host species on intestinal microbiota by comparing the gut bacterial community structure
of four cohabitating freshwater fish larvae, silver carp, grass carp, bighead carp, and blunt snout bream, using denaturing
gradient gel electrophoresis (DGGE) of the amplified 16S and 18S rRNA genes. Similarity clustering indicated that the intestinal
microbiota derived from these four fish species could be divided into four groups based on 16S rRNA gene similarity, whereas
the eukaryotic 18S rRNA genes showed no distinct groups. The water sample from the shared environment contained microbiota
of an independent group as indicated by both 16S and 18S rRNA genes segments. The bacterial community structures were visualized
using rank-abundance plots fitted with linear regression models. Results showed that the intestinal bacterial evenness was
significantly different between species (P<0.05) and between species and the water sample (P<0.01). Thirty-five relatively dominant bands in DGGE patterns were sequenced and grouped into five major taxa: Proteobacteria (26), Actinobacteria (5), Bacteroidetes (1), Firmicutes (2), and Cyanobacterial (1). Six eukaryotes were detected by sequencing 18S rRNA genes segments. The present study suggests that the intestines of
the four fish larvae, although reared in the same environment, contained distinct bacterial populations, while intestinal
eukaryotic microorganisms were almost identical. 相似文献
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Geum-Sook Do Bong-Bo Seo Jae-Hong Pak In-Sun Kim Seung-Dal Song 《Journal of Plant Biology》2000,43(3):143-148
Using the fluorescence in situ hybridization (FISH) technique, we conducted karyotype analyses to identify the lost chromosomes
in three somaclonal variants obtained from tissue culture of wildAllium tuberosum (2n = 4X = 32). The three lost chromosomes of the At29 variant (2n = 29) were all chromosome 2, the two for At30 (2n = 30)
were chromosomes 7 and 8, and At31 was missing chromosome 2. Chromosome compositions of these variants were confirmed as being
fixed lines during two years of greenhouse cultivation. The bicolor FISH technique, involving both 5S and 18S–5.8S–26S ribosomal
RNA genes as probes, was used to assign chromosomal locations and to confirm whether the lost chromosomes contained any rRNA
markers. The 5S rRNA gene signals in all variants as well as the wild type were detected as two sets, one on the intercalary
region of the short arm of chromosome 3, the other on the intercalary region of the long arm of chromosome 6. One 18S–5.8S–26S
rRNA gene site on the secondary constriction included a flanking satellite and terminal region on the short arm of chromosome
8. Signals of the 18S–5.8S–26S rRNA gene in At30 showpd in only three chromosomes, indicating that one of the lost chromosomes
was chromosome 8. Overall, three marker chromosomes were established by FISH, using rRNA multigene families. 相似文献
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Effects of insulin on the fine structure of hepatocytes from winter-acclimatized carps: studies on protein synthesis 总被引:1,自引:0,他引:1
Male and female winter-acclimatized carps were injected with insulin. This treatment resulted in a sharp decrease in the liver glycogen content. Although an increase in the ribosomal RNA level was also observed, a cell-free system obtained from the hormone-treated fish exhibited less amino acid incorporation activity as compared to the control fish. However, polysomes from insulin-treated fish exhibited a higher amino acid incorporating activity when a soluble fraction of untreated winter carps was used. Insulin induced a profound change in the cytoarchitecture of the winter carp hepatocyte. The cytoplasm and nuclei showed all the features of the summer carp liver cell. The nucleolar components were totally intermingled suggesting a high rate of gene expression as in the case of the summer-acclimatized fish. 相似文献
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Doucette LI Geiser F 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2008,151(4):615-620
Many birds living in regions with seasonal fluctuations in ambient temperatures (Ta) typically respond to cold by increasing insulation and adjusting metabolic rate. Seasonal variation in thermal physiology has not been studied for the Caprimulgiformes, an order of birds that generally have basal metabolic rates (BMR) lower than predicted for their body mass. We measured the metabolic rate and thermal conductance of Australian owlet-nightjars (Aegotheles cristatus) during summer and winter using open-flow respirometry. Within the thermoneutral zone (TNZ; 31.3 to 34.8 °C), there was no seasonal difference in BMR or thermal conductance (C), but body temperature was higher in summer- (38.2 ± 0.3 °C) than winter-acclimatized (37.1 ± 0.5 °C) birds. Below the TNZ, resting metabolic rate (RMR) increased linearly with decreasing Ta, and RMR and C were higher for summer- than winter-acclimatized birds. The mean mass-specific BMR of owlet-nightjars (1.27 mL O2 g− 1 h− 1) was close to the allometrically predicted value for a 45 g Caprimulgiformes, but well below that predicted for birds overall. These results suggest that owlet-nightjars increase plumage insulation to cope with low winter Ta, which is reflected in the seasonal difference in RMR and C below the TNZ, rather than adjusting BMR. 相似文献