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31.
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European badgers (Meles meles) are group‐living mustelids implicated in the spread of bovine tuberculosis (TB) to cattle and act as a wildlife reservoir for the disease. In badgers, only a minority of individuals disperse from their natal social group. However, dispersal may be extremely important for the spread of TB, as dispersers could act as hubs for disease transmission. We monitored a population of 139 wild badgers over 7 years in a medium‐density population (1.8 individuals/km2). GPS tracking collars were applied to 80 different individuals. Of these, we identified 25 dispersers, 14 of which were wearing collars as they dispersed. This allowed us to record the process of dispersal in much greater detail than ever before. We show that dispersal is an extremely complex process, and measurements of straight‐line distance between old and new social groups can severely underestimate how far dispersers travel. Assumptions of straight‐line travel can also underestimate direct and indirect interactions and the potential for disease transmission. For example, one female disperser which eventually settled 1.5 km from her natal territory traveled 308 km and passed through 22 different territories during dispersal. Knowledge of badgers' ranging behavior during dispersal is crucial to understanding the dynamics of TB transmission, and for designing appropriate interventions, such as vaccination.  相似文献   
33.
Diversity of Frankia microsymbionts of non-native Elaeagnus angustifolia L. plants spontaneously growing in a Tunisian desertic retreat area, the date-palm oasis of Tozeur, was investigated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR-sequencing techniques targeting the nifD-K intergenic spacer. Three PCR-RFLP haplotypes (I, II, and III) were detected among collected nodules. Haplotype I was detected at all five sampling sites and dominated the other haplotypes present at these sites. This haplotype was also exhibited by strain BMG5.10, which was isolated by a plant-capturing assay in 1998 from soil collected in the same locality, qualifying it to be the most competitive haplotype in the edapho-climatic condition of the studied desertic date-palm oasis. nifD-K sequences of the three haplotypes formed a closely related phylogenetic subgroup. These results suggest that Frankia variability is constrained by severe edapho-climatic conditions of retreated desert in Tunisian area.  相似文献   
34.
Array based comparative genomic hybridisation (aCGH) is a powerful technique for detecting clinically relevant genome imbalance and can offer 40 to > 1000 times the resolution of karyotyping. Indeed, idiopathic learning disability (ILD) studies suggest that a genome-wide aCGH approach makes 10–15% more diagnoses involving genome imbalance than karyotyping. Despite this, aCGH has yet to be implemented as a routine NHS service. One significant obstacle is the perception that the technology is prohibitively expensive for most standard NHS clinical cytogenetics laboratories. To address this, we investigated the cost-effectiveness of aCGH versus standard cytogenetic analysis for diagnosing idiopathic learning disability (ILD) in the NHS. Cost data from four participating genetics centres were collected and analysed. In a single test comparison, the average cost of aCGH was £442 and the average cost of karyotyping was £117 with array costs contributing most to the cost difference. This difference was not a key barrier when the context of follow up diagnostic tests was considered. Indeed, in a hypothetical cohort of 100 ILD children, aCGH was found to cost less per diagnosis (£3,118) than a karyotyping and multi-telomere FISH approach (£4,957). We conclude that testing for genomic imbalances in ILD using microarray technology is likely to be cost-effective because long-term savings can be made regardless of a positive (diagnosis) or negative result. Earlier diagnoses save costs of additional diagnostic tests. Negative results are cost-effective in minimising follow-up test choice. The use of aCGH in routine clinical practice warrants serious consideration by healthcare providers. Copyright statement The Corresponding Author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive licence (or non exclusive for government employees) on a worldwide basis to the BMJ Publishing Group Ltd, and its Licensees to permit this article (if accepted) to be published in BMJ editions and any other BMJPGL products and to exploit all subsidiary rights, as set out in our licence (bmj.com/advice/copyright.shtml). Authorship The authors included on this paper fulfil the criteria of authorship and no one who fulfils the criteria has been excluded from authorship. The authors made a substantial contribution to the conception, design, analysis and interpretation of data. They were involved in drafting the article or revising it critically for important intellectual content and approving the version to be published. Contributorship Sarah Wordsworth (Guarantor): Planning, conducting and reporting work, interpretation of data, drafting and revising article. James Buchanan: Conducting and reporting work, interpretation of data, revising article. Regina Regan: Completing costing questionnaire, providing protocol details, other costing information, interpretation of data, information about learning disability and genome imbalance and revising article. Val Davison: Completing costing questionnaire, providing protocol details, sharing overall laboratory experience and drafting article. Kim Smith: Completing costing questionnaire, providing protocol details, drafting article. Sara Dyer: Completing costing questionnaire and providing protocol details. Carolyn Campbell: Completing costing questionnaire and providing protocol details. Edward Blair: Critical appraisal of article for clinical content and revising article. Eddy Maher: Completing costing questionnaire, providing protocol details, sharing overall laboratory experience and drafting article. Jenny Taylor: Planning and facilitating work between centres. Drafting and revising article. Samantha JL Knight: Completing costing questionnaire, providing protocol details, other costing information, interpretation of data, providing information about learning disability and genome imbalance, drafting and revising article. Jenny Taylor and Samantha JL Knight contributed equally to the work presented.  相似文献   
35.
The base excision repair pathway removes damaged DNA bases and resynthesizes DNA to replace the damage. Human alkyladenine DNA glycosylase (AAG) is one of several damage-specific DNA glycosylases that recognizes and excises damaged DNA bases. AAG removes primarily damaged adenine residues. Human AP endonuclease 1 (APE1) recognizes AP sites produced by DNA glycosylases and incises the phophodiester bond 5' to the damaged site. The repair process is completed by a DNA polymerase and DNA ligase. If not tightly coordinated, base excision repair could generate intermediates that are more deleterious to the cell than the initial DNA damage. The kinetics of AAG-catalyzed excision of two damaged bases, hypoxanthine and 1,N6-ethenoadenine, were measured in the presence and absence of APE1 to investigate the mechanism by which the base excision activity of AAG is coordinated with the AP incision activity of APE1. 1,N6-ethenoadenine is excised significantly slower than hypoxanthine and the rate of excision is not affected by APE1. The excision of hypoxanthine is inhibited to a small degree by accumulated product, and APE1 stimulates multiple turnovers by alleviating product inhibition. These results show that APE1 does not significantly affect the kinetics of base excision by AAG. It is likely that slow excision by AAG limits the rate of AP site formation in vivo such that AP sites are not created faster than can be processed by APE1.  相似文献   
36.
A novel, low molecular weight, intracellular isoform of FGF receptor-1 (FGFR-1) was identified in embryonic chicken tissues using several antibodies specific for different domains of FGF receptors. This low molecular weight isoform differs from the previously characterized isoforms of FGFR-1 in that it contains little or no carbohydrate. Furthermore, in contrast to the other isoforms of FGFR-1, this novel isoform is located exclusively intracellularly. However, it is capable of binding 125I-FGF-2 and it possesses intrinsic kinase activity. Pulse-chase experiments indicate that this isoform of FGFR-1 is not simply a precursor to glycosylated FGFR-1 since it can be detected long after the appearance of glycosylated FGFR-1 in the cells. These results suggest that the novel FGFR-1 isoform plays a role in regulating FGF activity distinct from cell surface, glycosylated FGFR-1. The possible roles of this FGFR-1 variant in FGF signaling are discussed. © 1996 Wiley-Liss, Inc.  相似文献   
37.
Peroxisome proliferator activated receptor gamma (PPARgamma) is a nuclear hormone receptor that has been shown to regulate differentiation and cell growth. Studies of the differentiative effects of PPARgamma agonists on several cancer cell lines led to the hypothesis that dysfunction of PPARgamma contributes to tumorigenesis. These functional observations were strengthened by genetic evidence: somatic loss-of-function mutations in PPARG, encoding PPARgamma, in sporadic colorectal carcinomas and somatic translocation of PAX8 and PPARG in follicular thyroid carcinoma. Recently overrepresentation of the H449H variant was found in a cohort of American patients with glioblastoma multiforme. The glioblastoma multiforme data suggest that PPARG contributes common, low-penetrance alleles for cancer susceptibility. To test this hypothesis in a broader range of cancers we examined a series of carcinomas of the cervix, endometrium, ovary, prostate, and kidney for germline sequence variation in PPARG. In addition to the two common sequence variants, P12A and H449H, there were five other sequence variants. P12A alleles were underrepresented in renal cell carcinoma patients compared to country-of-origin race-matched controls (3.75% vs. 12.1%, P<0.04). In contrast, the H449H variant was overrepresented in individuals with endometrial carcinoma compared to controls (14.4% vs. 6.25%, P<0.02). These observations lend genetic evidence consistent with our hypothesis that PPARG serves as a common, low-penetrance susceptibility gene for cancers of several types, especially those epidemiologically associated with obesity and fat intake.  相似文献   
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Natural history collections are repositories of biodiversity and are potentially used by molecular ecologists for comparative taxonomic, phylogenetic, biogeographic and forensic purposes. Specimens in fish collections are preserved using a combination of methods with many fixed in formalin and then preserved in ethanol for long-term storage. Formalin fixation damages DNA, thereby limiting genetic analyses. In this study, the authors compared the DNA barcoding and identification success for frozen and formalin-fixed tissues obtained from specimens in the CSIRO Australian National Fish Collection. They studied 230 samples from fishes (consisting of >160 fish species). An optimized formalin-fixed, paraffin-embedded DNA extraction method resulted in usable DNA from degraded tissues. Four mini barcoding assays of the mitochondrial DNA (mtDNA) were characterized with Sanger and Illumina amplicon sequencing. In the good quality DNA (without exposure to formalin), up to 88% of the specimens were correctly matched at the species level using the cytochrome oxidase subunit 1 (COI) mini barcodes, whereas up to 58% of the specimens exposed to formalin for less than 8 weeks were correctly identified to species. In contrast, 16S primers provided higher amplification success with formalin-exposed tissues, although the COI gene was more successful for identification. Importantly, the authors found that DNA of a certain size and quality can be amplified and sequenced despite exposure to formalin, and Illumina sequencing provided them with greater power of resolution for taxa identification even when there was little DNA present. Overall, within parameter constraints, this study highlights the possibilities of recovering DNA barcodes for identification from formalin-fixed fish specimens, and the authors provide guidelines for when successful identification could be expected.  相似文献   
40.
The taxonomic position of an actinobacterial isolate, designated strain BMG 822T, isolated from limestone from the Amphitheater of El Jem (Coliseum Thysdrus), Tunisia, was established using a polyphasic approach. Strain BMG 822T was found to grow well at 30 °C and pH 6.5–8.0, and to be coral-coloured, Gram-positive, catalase and oxidase negative. Whole cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, glucose, galactose and ribose. The phospholipids detected were diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, an unidentified glycophospholipid and six unidentified phospholipids. MK-9(H4) was found to be the predominant menaquinone, followed by MK-9(H2) and MK-9. The major cellular fatty acids were identified as iso-C16:0, C18:1 ω9c, C17:1 ω8c and iso-H-C16:1. The G+C content of the DNA (73.2%) is typical of the genus. High degrees of 16S rRNA gene sequence similarity were found with the type strains of the genus Blastococcus (97.1–98.3%) followed by the type strains of Modestobacter (96.8–97.8%). Based on the above data and the phenotypic differences from the type strains of Blastococcus species, it is proposed that the isolate BMG 822T (=DSM 46837T=CECT 8823T) should be classified as the type strain of a novel species, Blastococcus colisei sp. nov.  相似文献   
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