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Many arthropods with restricted diets rely on symbiotic associations for full nutrition and fecundity. Tsetse flies (Diptera:
Glossinidae) harbor three symbiotic organisms in addition to the parasitic African trypanosomes they transmit. Two of these microorganisms
reside in different gut cells, while the third organism is harbored in reproductive tissues and belongs to the genus Wolbachia. The primary symbiont (genus Wigglesworthia glossinidia) lives in differentiated epithelial cells (bacteriocytes) which form an organ (bacteriome) in the anterior gut, while the
secondary (S) symbionts are present in midgut cells. Here we have characterized the phylogeny of Wigglesworthia based on their 16S rDNA sequence analysis from eight species representing the three subgenera of Glossina: Austenina (=fusca group), Nemorhina (=palpalis group), and Glossina (=morsitans group). Independently, the ribosomal DNA internal transcribed spacer-2 (ITS-2) regions from these species were analyzed.
The analysis of Wigglesworthia indicated that they form a distinct lineage in the γ subdivision of Proteobacteria and display concordance with their host
insect species. The trees generated by parsimony confirmed the monophyletic taxonomic placement of Glossina, where fusca group species formed the deepest branch followed by morsitans and palpalis groups, respectively. The placement of the species Glossina austeni by both the traditional morphological and biochemical criteria has been controversial. Results presented here, based on both
the ITS-2 and the symbiont 16S rDNA sequence analysis, suggest that Glossina austeni should be placed into a separate fourth subgenus, Machadomyia, which forms a sister-group relationship with the morsitans group species.
Received: 17 March 1998 / Accepted: 1 May 1998 相似文献
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Influence of Precursor Availability on Alkaloid Accumulation by
Transgenic Cell Line of Catharanthus roseus 总被引:7,自引:0,他引:7 下载免费PDF全文
Serap Whitmer Camilo Canel Didier Hallard Cecilia Gon?alves Robert Verpoorte 《Plant physiology》1998,116(2):853-857
We have used a transgenic cell line of Catharanthus roseus (L.) G. Don to study the relative importance of the supply of biosynthetic precursors for the synthesis of terpenoid indole alkaloids. Line S10 carries a recombinant, constitutively overexpressed version of the endogenous strictosidine synthase (Str) gene. Various concentrations and combinations of the substrate tryptamine and of loganin, the immediate precursor of secologanin, were added to suspension cultures of S10. Our results indicate that high rates of tryptamine synthesis can take place under conditions of low tryptophan decarboxylase activity, and that high rates of strictosidine synthesis are possible in the presence of a small tryptamine pool. It appears that the utilization of tryptamine for alkaloid biosynthesis enhances metabolic flux through the indole pathway. However, a deficiency in the supply of either the iridoid or the indole precursor can limit flux through the step catalyzed by strictosidine synthase. Precursor utilization for the synthesis of strictosidine depends on the availability of the cosubstrate; the relative abundance of these precursors is a cell-line-specific trait that reflects the metabolic status of the cultures. 相似文献
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Osteoporosis is a common disorder, with prolongation of the average life span it has become a major public health problem. On the formation of osteoporosis genetic factors and environmental influences could play a role then it is considered as multi-factorial. Because a variety of functions to affect susceptibility to the formation of osteoporosis VDR-F, VDR-B, COL1A1, ESR1X, ESR1P and CTR are thought to be candidate genes. In this study, the aim is to investigate the relationship between these genes polymorphism and bone mineral density (BMD) values of lumbar vertebra and femoral neck in 188 Turkish people. Lumbar spine and femoral neck BMD of the individuals included in the study were measured by the dual X-ray absorptiometry method. The genotyped polymorphisms by simultaneous amplification of five regions of the genome, containing six SNPs of interest and detecting the amplified product, using the kit MetaBone Clinical Arrays?. Statistical analyses indicated that; VDR-B gene polymorphisms major (P?=?0.013), VDR-F polymorphisms have minor (P?=?0.082) effect on femur BMD. None of the other genes has any significant effect on spinal BMD. Patient age, body mass index and diet has significant effect on femoral and spinal BMD. Osteoporosis is a multi-factorial disease and many genetic and non-genetic risk factors contribute to the development of osteoporosis. Early detection of a genetic predisposition to osteoporosis should allow delay and/or limit unfavorable changes in the bone tissue. 相似文献
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The conservation of beetles that depend on dying or dead wood (i.e. saproxylic), has received a great deal of attention in many parts of the world in recent years. Human activities such as urbanization and logging, and their results, e.g. global warming, destroy natural ecosystems and threaten unusual species such as Lucanus cervus (L. 1758), Rosalia alpina (L. 1758), Limoniscus violaceus (Müller 1821) and Osmoderma eremita (Scopoli 1763). Attempts have been made to conserve the habitats upon which these species depend. Although represented by a large number of species, saproxylic beetles in Turkey have not received much attention. Although some Turkish studies have acknowledged their value, comprehensive investigations of these species are very limited. The aim of this study is to make a list, from the literature, of the species that are endangered in Europe and found in Turkey, to highlight the importance of these species. The research includes 151 saproxylic beetle species belonging to the families Bostrichidae, Cerambycidae, Elateridae, Eucnemidae, Scarabaeidae, Euchiridae, Lucanidae and Mycetophagidae. The list of Turkish saproxylic beetles was prepared using the European Red List of Saproxylic Beetles. Information is provided about the IUCN Red List category in Europe, the locations of the species in Turkey, and their global geographic range. We gathered all data about these species from the international literature. Furthermore, we also include in the list certain species whose locations are not specified, but which inhabit Turkey. We obtained their records from some catalogs in Turkey. In addition to the list, we prepared three distribution maps for Turkey. The maps show distribution in Turkey of some species in the Endangered, Vulnerable and Near Threatened categories in the European Red List. It is expected that this study will lead to comprehensive studies on saproxylic beetles from Turkey. 相似文献
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Protective effects of ascorbic acid, Dl-α-tocopherol acetate, and sodium selenate on ethanol-induced gastric mucosal injury of rats 总被引:2,自引:0,他引:2
Ozdil S Yanardag R Koyuturk M Bolkent S Arbak S 《Biological trace element research》2004,99(1-3):173-189
In this study, the effect of ascorbic acid (vitamin C), Dl-α-tocopherol acetate (vitamin E), and sodium selenate (selenium) on ethanol-induced gastric mucosal injury in rats was investigated
morphologically and biochemically. The gastric mucosal injury was produced by administration of 1 mL of absolute ethanol to
each rat. Animals received vitamin C (250 mg/kg), vitamin E (250 mg/kg), and selenium (0.5 mg/kg) for 3 d 1 h prior to the
administration of absolute ethanol. In gastric mucosa of rats given ethanol according to control groups, neuronal nitric oxide
expression decreased. This immunoreactivity was much lower in the group given ethanol+vitamin C+vitamin E+selenium than the
control group and the ethanol-induced group. Scanning electron microscopic evaluation of the ethanol-induced group, when compared
to control groups, revealed degenerative changes in gastric mucosa, whereas a good arrangement in surface topography of gastric
mucosa in the group given ethanol + vitamin C+vitamin E + selenium was observed. In the group administered ethanol, a reduction
of the stomach glutathione (GSH) and serum total protein levels and increases in serum sialic acid, triglycerides, and stomach
lipid peroxidation (LPO) levels were observed. Vitamin C+vitamin E+Se administration to alcohol-treated rats significantly
increased the serum total protein, triglyceride levels, and stomach GSH levels and significantly lowered the levels of serum
sialic acid and stomach LPO compared to untreated alcohol-supplemented rats. As a result of these findings, we can say that
the combination of vitamin C, vitamin E, and selenium has a protective effect on ethanol-induced gastric mucosal injury of
rats. 相似文献
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The question of virginity testing in Turkey 总被引:2,自引:0,他引:2
Pelin SS 《Bioethics》1999,13(3-4):256-261
Pre-marital sex for a woman is regarded as wrong in my country. As a result, it is socially forbidden for a woman to engage in this act. In order to present a woman as a virgin on her marriage day, she is subjected to pressure, and put under control both by her family and societal norms. However, a man is free and never made to suffer any of the above. A woman found to be a virgin on her first night of marriage is seen as a normal person while one suspected to have lost her virginity is made to undergo a series of medical examinations to bring clarity to her situation. 相似文献