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1.
自1989年从绵羊下丘脑提取物发现垂体腺苷酸环化酶激活多肽(Pituitary adenylate cyclase activating polypeptide,PACAP)以来(Miyata et al.,1989),已证明它能促进垂体激素释放,同时还具有神经递质、神经调质和神经营养等作用,使对PACAP的研究成为十分活跃的领域。PACAP属于血管活性肠肽(VIP)-胰高血糖素-生长激素释放因子-分泌素家族(Campbell and Scanes,1992)成员,已鉴别出包含27和38个氨基酸两种类型。对原索动物(McRory et al.,1997)、两栖类(蛙)(Alexandre et al.,2000)、爬行类(蜥蜴)(Pohland Wank,1998)、鸟类(鸡)(McRory et al.,1997),啮齿类(鼠)(Ghatei et al.,1993)等脊椎动物PACAP的研究多集中在结构与进化方面,对功能了解甚少。 相似文献
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多位点DNA指纹技术在保加利亚普通田鼠中的应用探讨 总被引:1,自引:0,他引:1
DNA指纹是一种重要的现代分子遗传学标记技术(Jeffreys et al.,1985),它所揭示的是生物体大量的、无遗传编码信息的、具有高度多态性的卫星DNA(Chen,1996)。这些DNA序列往往占据了生物体基因组总量的80%以上,由于它不编码蛋白基因,在系统发育过程中,通常不被自然选择和人工选择,使得生物变异积累形成个体基因组间的巨大差异。因此,DNA指纹受到生物学家的青睐,以用于生物个体和群体的基因组分析(Burke and Bruford,1987;Buitmap et al.,1991;Weising et al.,1995)。 相似文献
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尼罗鳄线粒体基因组全序列分析及鳄类系统发生关系的探讨 总被引:1,自引:0,他引:1
大多数脊椎动物的线粒体基因组(约16—18kb)的组成是相对较稳定的,但在不同类群中,线粒体基因组在基因结构和基因排列方式等方面均显示了极大的多样性,这种多样性可能反映了真核细胞不同的进化路线(Saccone et al.,1999)。就目前的研究而言,线粒体基因组是惟一一个能够从基因组水平上来分析动物系统发生的分子标记,可以从线粒体基因组序列信息、基因组成及基因排列方式等进行多方位的分子进化研究,因而线粒体基因组全序列将成为动物分子系统发生最有力的证据(Saccone et al.,1999)。 相似文献
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Two polypores from Yunnan new to China 总被引:3,自引:0,他引:3
YU Chang-Jun LIJuan DAI Yu-Cheng 《菌物系统》2008,(1):145-150
1 INTRODUCTION
Wood-rotting fungi have been intensively studied in China (Dai & Niemela 2002; Dai et al. 2003, 2004a, 2004b; Dai & Penttil/i 2006), and some new species and new records were found from tropical and subtropical forests in southern part of the Country (Cui et al. 2006b; Cui et al. 2007; Dai 2004; Dai & Cui 2005; Dai & Yuan 2005; Yuan et al. 2004). Some species are new forest pathogens (Cui et al. 2006a; Dai et al. 2001, 2002, 2004). 相似文献
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三疣梭子蟹蜕皮抑制激素cDNA的克隆与序列分析 总被引:1,自引:0,他引:1
甲壳动物的蜕皮是由位于头胸部前鳃腔的一对Y-器通过分泌蜕皮激素(Molting hormone)来控制的(Lachaise et al.,1993),而蜕皮激素的分泌又受到蜕皮抑制激素(Molt-inhibiting hormone,MIH)的调控(Watson et al.,2001)。MIH和性腺抑制激素(Gonad-inhibiting hormone,GIH)、甲壳动物高血糖激素(Crustacean hyperglycemic hormone,CHH)、 相似文献
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YUAN Hai-Sheng DAI Yu-Cheng 《菌物系统》2008,(1):151-155
1 INTRODUCTION
Wood-inhabiting fungi from northern China were investigated extensively during last ten years, and the species in the area are relatively well known (Dai 2000; Dai et al. 2006, 2007; Wei et al. 2005; Yuan et al. 2006). However, they are scantily reported in tropical forests of China (Dai et al. 2001, 2002, 2004). By the support of the Ministry of Science and Technology of China, two field investigations were made in Jianfengling and Bawangling Nature Reserve of Hainan Province in 2006. 相似文献
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The analysis of prey DNA in faeces is a non-invasive approach to examine the diet of birds. However, it is poorly known how gut transition time, environmental factors and laboratory treatments such as storage conditions or DNA extraction procedures affect the detection success of prey DNA. Here, we examined several of these factors using faeces from carrion crows fed with insect larvae. Faeces produced between 30 min and 4 h post-feeding tested positive for insect DNA, representing the gut transition time. Prey detection was not only possible in fresh but also in 5-day-old faeces. The type of surface the faeces were placed on for these 5 days, however, affected prey DNA detection success: samples placed on soil provided the lowest rate of positives compared to faeces left on leaves, on branches and within plastic tubes. Exposing faeces to sunlight and rain significantly lowered prey DNA detection rates (17% and 68% positives in exposed and protected samples, respectively). Storing faeces in ethanol or in the freezer did not affect molecular prey detection. Extracting DNA directly from larger pieces of faecal pellets resulted in significantly higher prey detection rates than when using small amounts of homogenized faeces. A cetyltrimethyl ammonium bromide-based DNA extraction protocol yielded significantly higher DNA detection rates (60%) than three commercial kits, however, for small amounts of homogenized faeces only. Our results suggest that collecting faeces from smooth, clean and non-absorbing surfaces, protected from sunlight and rain, improves DNA detection success in avian faeces. 相似文献
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A comparison of five methods for extraction of bacterial DNA from human faecal samples 总被引:17,自引:0,他引:17
The purity of DNA extracted from faecal samples is a key issue in the sensitivity and usefulness of biological analyses such as PCR for infectious pathogens and non-pathogens. We have compared the relative efficacy of extraction of bacterial DNA (both Gram negative and positive origin) from faeces using four commercial kits (FastDNA kit, Bio 101; Nucleospin C+T kit, Macherey-Nagal; Quantum Prep Aquapure Genomic DNA isolation kit, Bio-Rad; QIAamp DNA stool mini kit, Qiagen) and a non-commercial guanidium isothiocyanate/silica matrix method. Human faecal samples were spiked with additional known concentrations of Lactobacillus acidophilus or Bacteroides uniformis, the DNA was then extracted by each of the five methods, and tested in genus-specific PCRs. The Nucleospin method was the most sensitive procedure for the extraction of DNA from a pure bacterial culture of Gram-positive L. acidophilus (10(4) bacteria/PCR), and QIAamp and the guanidium method were most sensitive for cultures of Gram-negative B. uniformis (10(3) bacteria/PCR). However, for faecal samples, the QIAamp kit was the most effective extraction method and led to the detection of bacterial DNA over the greatest range of spike concentrations for both B. uniformis and L. acidophilus in primary PCR reactions. A difference in extraction efficacy was observed between faecal samples from different individuals. The use of appropriate DNA extraction kits or methods is critical for successful and valid PCR studies on clinical, experimental or environmental samples and we recommend that DNA extraction techniques are carefully selected with particular regard to the specimen type. 相似文献
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一种从大熊猫粪便中提取DNA的改进方法 总被引:30,自引:0,他引:30
本研究描述一个改进的方法,使从大熊猫粪便中提取DNA用于PCR扩增变得更加容易。在粪便DNA的提取过程中采用一个新的预处理方法,将粪便用预冷的丙酮洗2~3次,除去粪便中含有的大量PCR抑制物,然后用蛋白酶K裂解、酚氯仿抽提,能提取到纯度很高的DNA供PCR扩增。本实验PCR扩增了大熊猫脑源性神经营养因子(BDNF)基因和线粒体细胞色素6基因片段,并进行测序分析,证实了提取的可靠性。对比本方法和未经丙酮预处理的方法提取的DNA进行PCR扩增,前者的扩增结果明显优于后者。 相似文献
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Mtambo J Van Bortel W Madder M Roelants P Backeljau T 《Experimental & applied acarology》2006,38(2-3):189-199
Five differently preserved groups of adult Rhipicephalus appendiculatus specimens were compared for quality of DNA extracted. Three methods were used to extract DNA from specimens i.e. two simple
mosquito validated DNA extraction methods and a tick validated method. Extraction of DNA from tick legs was attempted. The
quality of DNA extracted was evaluated by the success of PCR amplification of the ITS2 gene and the mitochondrial COI gene
fragment. Fresh specimens (i.e. killed just before extraction) had the highest success of DNA amplification followed by specimens
killed in ethanol and subsequently stored in the refrigerator (4 °C). There was no significant difference in amplification
success between cryopreserved and 70% ethanol preserved specimens. It was possible to amplify DNA from legs of ticks. Sequenced
ITS2 amplicon of template obtained from legs of ticks was as legible as those from whole tick extract. The two mosquito validated
DNA extraction methods showed a significantly lower amplification success than the tick validated protocol. 相似文献
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Tang JN Zeng ZG Wang HN Yang T Zhang PJ Li YL Zhang AY Fan WQ Zhang Y Yang X Zhao SJ Tian GB Zou LK 《Journal of microbiological methods》2008,75(3):432-436
Polymerase chain reaction (PCR) detection of microorganism in faecal specimens is hampered by poor recovery of DNA and by the presence of PCR inhibitors. In this paper, we describe a new modified method for extracting PCR-quality microbial community DNA from pig faecal samples, which combines the pretreatment with polyformaldehyde, and subsequent DNA lysis in the presence of CTAB, salt, PVP, and beta-mercaptoethanol, followed by isolation of nucleic acids using chloroform (no phenol) based protocol. The method resulted in a 1.3- to 11-fold increase in DNA yield when compared to four other widely used methods. Genomic DNA extracted from all five methods was assessed by both agarose gel electrophoresis and polymerase chain reaction for amplification of 16S rDNA specific fragments. The results showed that the improved method represented a reproducible, simple, and rapid technique for routine DNA extraction from faecal specimens and was notably better than using the QIAamp DNA Stool Mini Kit. 相似文献
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Empirical evaluation of preservation methods for faecal DNA 总被引:30,自引:0,他引:30
M. A. J. FRANTZEN J. B. SILK J. W. H. FERGUSON R. K. WAYNE & M. H. KOHN 《Molecular ecology》1998,7(10):1423-1428
We evaluate the relative effectiveness of four methods for preserving faecal samples for DNA analysis. PCR assays of fresh faecal samples collected from free-ranging baboons showed that amplification success was dependent on preservation method, PCR-product size, and whether nuclear or mitochondrial DNA was assayed. Storage in a DMSO/EDTA/Tris/salt solution (DETs) was most effective for preserving nuclear DNA, but storage in 70% ethanol, freezing at –20°C and drying performed approximately equally well for mitochondrial DNA and short (<200 bp) nuclear DNA fragments. Because faecal DNA is diluted and degraded, repeated extractions from faeces may be necessary and short nuclear markers should be employed for genotyping. A review of molecular scatology studies further suggests that three to six faeces per individual should be collected. 相似文献
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M G Savill S R Murray P Scholes E W Maas R E McCormick E B Moore B J Gilpin 《Journal of microbiological methods》2001,47(3):355-368
Rhodococcus coprophilus, a natural inhabitant of herbivore faeces, has been suggested as a good indicator of animal (as opposed to human) faecal contamination of aquatic environments. However, conventional detection methods limit its use for this as they require up to 21 days to obtain a result. In this paper an optimised method for extracting R. coprophilus DNA from faecal samples is described. PCR and 5'-nuclease (TaqMan) PCR methods were developed to allow the detection and enumeration of R. coprophilus in faecal samples within 2-3 days. Both PCR methods targeted the 16S rRNA gene, producing an amplicon of 443 bp which was specific for R. coprophilus. Sixty cells were required to produce an amplification product by conventional PCR, while as little as one cell was required for the TaqMan PCR method. The latter approach gave a linear quantitative response over at least four log units with both bacterial cells and DNA. Successful amplification by PCR was achieved using DNA extracted from cow, sheep, horse and deer faeces but was negative for samples from humans, pig, possum, duck and rabbit. These PCR methods enhance the feasibility of using R. coprophilus to distinguish faecal pollution of farmed herbivores from human pollution. 相似文献
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《Journal of microbiological methods》2009,76(3):432-436
Polymerase chain reaction (PCR) detection of microorganism in faecal specimens is hampered by poor recovery of DNA and by the presence of PCR inhibitors. In this paper, we describe a new modified method for extracting PCR-quality microbial community DNA from pig faecal samples, which combines the pretreatment with polyformaldehyde, and subsequent DNA lysis in the presence of CTAB, salt, PVP, and β-mercaptoethanol, followed by isolation of nucleic acids using chloroform (no phenol) based protocol. The method resulted in a 1.3- to 11-fold increase in DNA yield when compared to four other widely used methods. Genomic DNA extracted from all five methods was assessed by both agarose gel electrophoresis and polymerase chain reaction for amplification of 16S rDNA specific fragments. The results showed that the improved method represented a reproducible, simple, and rapid technique for routine DNA extraction from faecal specimens and was notably better than using the QIAamp® DNA Stool Mini Kit. 相似文献
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A comparison of DNA extraction and purification methods to detect Escherichia coli O157:H7 in cattle manure 总被引:1,自引:0,他引:1
Trochimchuk T Fotheringham J Topp E Schraft H Leung KT 《Journal of microbiological methods》2003,54(2):165-175
The extraction of DNA from manure and the subsequent polymerase chain reaction (PCR) amplification of virulence genes to detect pathogens require an effective method of purification. Four different methods were assessed for their effectiveness in extracting and purifying Escherichia coli O157:H7 DNA from cattle manure: phenol/chloroform purification, phenol/chloroform/Sepharose B4 spin columns, phenol/chloroform/polyvinylpolypyrrolidone (PVPP) spun columns, and Mo Bio UltraClean kit. A PCR assay targeting the shiga-like toxin I gene (sltI) was carried out to determine the effectiveness of the four methods in removing PCR inhibitors from the manure samples. All methods were used to extract a manure slurry and the cleanliness of the samples was tested by the PCR with varying concentrations of spiked E. coli O157:H7 target DNA. The PVPP spun columns and the UltraClean kit had the best detection limit, detecting 20 pg of E. coli DNA (about 2x10(3) cells) per 100 mg of manure. The UltraClean kit and the PVPP spun columns also had the best and similar detection limits of 3x10(4) CFU/100 mg manure when E. coli O157:H7 cells were spiked into the manure sample and purified by all four methods. The enrichment of cells after inoculation into manure was performed using tryptic soy broth at 37 degrees C for 5 h. Both the PVPP spun columns and the UltraClean kit methods were used to purify the enriched samples and were able to detect initial inocula of 6 CFU/100 mg manure, indicating that the two methods were highly efficient in purifying DNA from manure samples. 相似文献