A Dominant Inhibitor Gene Inhibits the Expression of Ht2 against Exserohilum turcicum Race 2 in Corn Inbred Lines Related to B₁₄     

H. Ceballos  V. E. Gracen 《Plant Breeding》1989,102(1):35-44

The purpose of this study was to elucidate the genetic cause for the lack of express ion of the gene Ht2 against Exserohilum turcicum race 2 on certain genetic backgrounds related to the inbred line B14. Two such inbreds (A635Rp and B59), susceptible to this pathogen were crossed onto the inbred Oh43—-Ht2Ht2. The following generations: F₁, F₂, F₃, F₄, backcrosses to both parents, selfings of the backcrosses, in addition to the parent lines, were evaluated for Ht2 expression in this study. Plants of each generation were inoculated with E. turcicum race 2 and evaluated for the expression of the chlorotic-lesion resistance determined by the gene Ht2. In spite of the reported dominance of Ht2 on some genetic backgrounds, the F₁ generations studied here did not show Ht2 resistant lesions. The data presented herein suggest that B₁₄ and related inbred lines carry a dominant gene(I) that inhibits the expression of the Ht2 gene. Chi-square analyses of the reactions of 108 progeny families studied supported this hypothesis.  相似文献   

Recapitulation of IVIG anti-inflammatory activity with a recombinant IgG Fc     

Anthony RM  Nimmerjahn F  Ashline DJ  Reinhold VN  Paulson JC  Ravetch JV 《Science (New York, N.Y.)》2008,320(5874):373-376

It is well established that high doses of monomeric immunoglobulin G (IgG) purified from pooled human plasma [intravenous immunoglobulin (IVIG)] confer anti-inflammatory activity in a variety of autoimmune settings. However, exactly how those effects are mediated is not clear because of the heterogeneity of IVIG. Recent studies have demonstrated that the anti-inflammatory activity of IgG is completely dependent on sialylation of the N-linked glycan of the IgG Fc fragment. Here we determine the precise glycan requirements for this anti-inflammatory activity, allowing us to engineer an appropriate IgG1 Fc fragment, and thus generate a fully recombinant, sialylated IgG1 Fc with greatly enhanced potency. This therapeutic molecule precisely defines the biologically active component of IVIG and helps guide development of an IVIG replacement with improved activity and availability.  相似文献   

Plant conservation: old problems, new perspectives   总被引：1，自引：0，他引：1  

Vernon H Heywood 《Biological conservation》2003,113(3):321-335

Nature conservation has changed from an idealistic philosophy to a serious technology(J. Harper, 1992)A review is given of the major conceptual changes that have taken place during the last 50 years in our understanding of the nature of plant conservation and of the principal methodological advances in undertaking conservation assessments and actions, largely through the incorporation of tools and techniques from other disciplines. The interrelationships between conservation and sustainable use are considered as well as the impact of the development of the discipline of conservation biology, the effects of the general acceptance of the concept of biodiversity and the practical implications of the implementation of the Convention on Biological diversity. The effect on conservation policy and management of the accelerating loss or conversion of habitats throughout the world and approaches for combating this are discussed.  相似文献   

Diagnostic testing patterns of natural Mycobacterium paratuberculosis infection in pygmy goats   总被引：1，自引：0，他引：1       下载免费PDF全文

Elizabeth J.B. Manning  Howard Steinberg  Vernon Krebs    Michael T. Collins 《Canadian journal of veterinary research》2003,67(3):213-218

Thirteen pygmy goats (Capra hircus) from a herd naturally infected with Mycobacterium avium ss. paratuberculosis (MPTB) were monitored with 4 diagnostic assays for 2 to 15 mo. Cellular and humoral immune responses to the infection were assessed with assays of gamma interferon (IFNγ), serum antibody [enzyme-linked immunosorbent assay (ELISA) and agar gel diffusion (AGID)], and radiometric fecal culture. Microscopic examination and radiometric culture of tissue from 12 sites were performed at necropsy. Goats were considered infected if MPTB was isolated from any tissue sample collected at necropsy. Mycobacterial isolates were confirmed as MPTB with an IS900 polymerase chain reaction assay. Ten goats whose antemortem tests indicated infection carried heavy organism burdens at necropsy, both within and beyond the gastrointestinal system. False-negative ELISA, AGID, and/or culture results were obtained in 5 of the 10 confirmed cases during the study period. In 3 goats with sporadic fecal shedding of MPTB or detectable IFNγ response, or both, no abnormalities were detected at necropsy and no MPTB was isolated from the tissue samples; the antemortem fecal-culture and IFNγ results were thus considered false-positive. Diagnosticians should be alert to the possibility of both false-positive and false-negative test results for Johne's disease in goats. False-positive fecal-culture results may occur when a high prevalence of infection exists in the herd and the premises are likely to be heavily contaminated. The diverse antemortem testing patterns seen in these goats underscore the importance of using varied diagnostic assays serially or in parallel to increase the likelihood of identifying all infected goats.  相似文献   

Observations on the Biology and Control of the Plum Fruit Moth     

J. D. R. Vernon 《Plant pathology》1971,20(3):106-110

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Acetyl-CoA carboxylase of sheep adipose tissue: problems of the assay and adaptation during fetal development     

R G Vernon  E Taylor 《Journal of animal science》1986,63(4):1119-1125

The rate of fatty acid synthesis of perirenal adipose tissue of fetal lambs decreased by 90% during the last month of gestation. There was also a 90% decrease in the activity of fatty acid synthetase during this period, but the activity of this enzyme exceeded lipogenic flux by a factor of 10. The activity of acetyl CoA carboxylase in the active state (initial activity) was very similar to the lipogenic flux in adipose tissue from lambs at 120 d of gestation; although activity decreased towards term, the decline was insufficient to account for the fall in rate of fatty acid synthesis. The study also shows that assay of acetyl CoA carboxylase in the active state of ovine adipose tissue and of caprine mammary gland requires the presence of citrate, thus differing from that for rat adipose tissue. Evidence that pyruvate carboxylase can interfere in the assay of acetyl CoA carboxylase also is presented.  相似文献   

关于饲料中的抗氧化剂   总被引：1，自引：0，他引：1  

吴杉  钟缇力  Brian Vernon 《国外畜牧学(猪与禽)》2003,23(1):18-19

如今 ,许多饲料产品都以其抗氧化剂含量来促销。这样做的理由是 ,据说猪吃下抗氧化剂可保持自身健康 ,尤其是在猪遭受应激的时候 ,或者是猪面临疾病侵害的时候。因此 ,养猪者不禁要问 :这些抗氧化剂究竟是什么东西呢 ?吃这些东西怎么会有好处呢 ?这要从现代猪的代谢说起。现代猪在从活重30千克生长到 110千克期间 ,会以每天 340～ 4 5 0千克的速度合成瘦肉组织。为此 ,猪要通过大量的各种代谢过程将养分转化为机体物质。要平衡蛋白质的合成和分解 ,就需要高水平的代谢活动。代谢活动的水平在幼猪极高 ,例如 :体重 15千克的猪每2 8天就将心…  相似文献   

Protein metabolism in animals treated with anabolic agents     

P J Buttery  B G Vernon 《Veterinary research communications》1983,7(1-4):11-17

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Effects of long-term thrice-daily milking on mammary enzyme activity, cell population and milk yield in the goat     

C J Wilde  A J Henderson  C H Knight  D R Blatchford  A Faulkner  R G Vernon 《Journal of animal science》1987,64(2):533-539

In two separate experiments, lactating goats were milked unilaterally thrice daily instead of twice daily for periods of 13 and 37 wk, starting at 2 to 5 wk after parturition. The other gland was milked twice daily throughout. In both experiments thrice-daily milking increased milk yield significantly. In the first experiment, after 37 wk the amounts of RNA and DNA, rate of cell proliferation and activities of several enzymes per cell were greater in the thrice-milked gland (P less than .05). In the second experiment, after 9 or 10 d of thrice-daily milking the activities of several key mammary enzymes per cell measured in biopsy samples had increased in the thrice-milked but not the twice-milked gland. After 13 wk of thrice-daily milking, the DNA content of the glands and the activity per cell of the key enzymes was the same in both glands, showing that the synthetic capacity of the gland was being used more effectively in the treated gland. These results indicate that several mechanisms contributed to the increased milk yield induced by thrice-daily milking.  相似文献   

Impact of regulatory perturbations to disease spread through cattle movements in Great Britain     

Vernon MC  Keeling MJ 《Preventive veterinary medicine》2012,105(1-2):110-117

During the past decade the British livestock industry has suffered from several major pathogen outbreaks, and a variety of regulatory and disease control measures have been applied to the movement of livestock with the express aim of mitigating the spread of infection. The Rapid Analysis and Detection of Animal-related Risks (RADAR) project, which has been collecting data on the movement of cattle since 1998, provides a relatively comprehensive record of how these policies have influenced the movement of cattle between animal holdings, markets, and slaughterhouses in Britain. Many previous studies have focused on the properties of the network that can be derived from these movements--treating farms as nodes and movements as directed (and potentially weighted) edges in the network. However, of far greater importance is how these policy changes have influenced the potential spread of infectious diseases. Here we use a stochastic fully individual-based model of cattle in Britain to assess how the epidemic potential has varied from 2000 to 2009 as the pattern of movements has changed in response to legislation and market forces. Our simulations show that the majority of policy changes lead to significant decreases in the epidemic potential (measured in multiple ways), but that this potential then increases through time as cattle farmers modify their behaviour in response. Our results suggest that the cattle industry is likely to experience boom-bust dynamics, with the actions that farmers take during epidemic-free periods to maximise their profitability likely to increase the potential for large-scale epidemics to occur.  相似文献