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11.
西瓜DUS测试标准品种SSR指纹图谱构建及应用   总被引:6,自引:0,他引:6  
本研究采用代表最大限度西瓜遗传多样性的SSR核心引物组合,分析了西瓜DUS测试指南中的24份标准品种遗传多样性与核酸指纹。以基于重测序获得的SNP标记构建的17份西瓜材料的系统发育树为参照,对24份标准品种进行了遗传多样性分析,在遗传相似系数0.80处将24份标准品种分为3大类群,分析表明:核酸指纹分类比传统形态学分类更为准确。采用二维(QR)编码构建了西瓜24份标准品种的SSR指纹图谱,并利用本技术以保护品种“京欣2号”与对照品种“京欣1号”为例,进行了DUS分子鉴定测试,共扩增32个SSR位点,“京欣1号”和“京欣2号”之间存在4个位点的差异,品种间遗传相似系数为0.89,比形态学鉴定的差异位点更多且更准。本研究建立的西瓜DUS标准品种SSR指纹图谱与分子检测技术,可以应用到西瓜品种DUS分子检测实践,同时也为西瓜品种纯度与真实性鉴定及遗传背景分析提供了技术方案。  相似文献   
12.
MicroRNAs are small non-coding RNAs that physiologically modulate proteins expression, and regulate numerous cellular mechanisms. Alteration of microRNA expression has been described in cancer and is associated to tumor initiation and progression. The microRNA 148a (miR-148a) is frequently down-regulated in cancer. We previously demonstrated that its down-regulation by DNA hypermethylation is an early event in pancreatic ductal adenocarcinoma (PDAC) carcinogenesis, suggesting a tumor suppressive function. Here, we investigate the potential role of miR-148a over-expression in PDAC as a therapeutic tool. We first report the consequences of miR-148a over-expression in PDAC cell lines. We demonstrate that miR-148a over-expression has no dramatic effect on cell proliferation and cell chemo-sensitivity in four well described PDAC cell lines. We also investigate the modulation of protein expression by a global proteomic approach (2D-DIGE). We show that despite its massive over-expression, miR-148a weakly modulates protein expression, thus preventing the identification of protein targets in PDAC cell lines. More importantly, in vivo data demonstrate that modulating miR-148a expression either in the epithelia tumor cells and/or in the tumor microenvironment does not impede tumor growth. Taken together, we demonstrate herein that miR-148a does not impact PDAC proliferation both in vitro and in vivo thus suggesting a weak potential as a therapeutic tool.  相似文献   
13.
王坤  马寨璞 《动物学杂志》2020,55(1):101-104
鳄蜥(Shinisauruscrocodilurus)是濒危的孑遗物种,生存遭受多方威胁。除人为猎杀和生境受到破坏之外,天敌也是其致命的威胁之一,但目前关于其被天敌捕食的研究非常匮乏。本文报道了绿瘦蛇(Ahaetullaprasina)捕食鳄蜥的现象,以全事件记录法观察了这一行为过程。鳄蜥面对的被捕食风险可能较广。除蛇外,鳄蜥的天敌也可能是鸟类等动物。在饲养繁育中,要注意加强防范举措,以免鳄蜥被天敌侵害。  相似文献   
14.

Background

Long-term benefits in animal breeding programs require that increases in genetic merit be balanced with the need to maintain diversity (lost due to inbreeding). This can be achieved by using optimal contribution selection. The availability of high-density DNA marker information enables the incorporation of genomic data into optimal contribution selection but this raises the question about how this information affects the balance between genetic merit and diversity.

Methods

The effect of using genomic information in optimal contribution selection was examined based on simulated and real data on dairy bulls. We compared the genetic merit of selected animals at various levels of co-ancestry restrictions when using estimated breeding values based on parent average, genomic or progeny test information. Furthermore, we estimated the proportion of variation in estimated breeding values that is due to within-family differences.

Results

Optimal selection on genomic estimated breeding values increased genetic gain. Genetic merit was further increased using genomic rather than pedigree-based measures of co-ancestry under an inbreeding restriction policy. Using genomic instead of pedigree relationships to restrict inbreeding had a significant effect only when the population consisted of many large full-sib families; with a half-sib family structure, no difference was observed. In real data from dairy bulls, optimal contribution selection based on genomic estimated breeding values allowed for additional improvements in genetic merit at low to moderate inbreeding levels. Genomic estimated breeding values were more accurate and showed more within-family variation than parent average breeding values; for genomic estimated breeding values, 30 to 40% of the variation was due to within-family differences. Finally, there was no difference between constraining inbreeding via pedigree or genomic relationships in the real data.

Conclusions

The use of genomic estimated breeding values increased genetic gain in optimal contribution selection. Genomic estimated breeding values were more accurate and showed more within-family variation, which led to higher genetic gains for the same restriction on inbreeding. Using genomic relationships to restrict inbreeding provided no additional gain, except in the case of very large full-sib families.  相似文献   
15.
Phagocytes restrict the germination of Aspergillus fumigatus conidia and prevent the establishment of invasive pulmonary aspergillosis in immunecompetent mice. Here we report that immunecompetent mice recovering from a primary A. fumigatus challenge are protected against a secondary lethal challenge. Using RAGγc knock-out mice we show that this protection is independent of T, B and NK cells. In protected mice, lung phagocytes are recruited more rapidly and are more efficient in conidial phagocytosis and killing. Protection was also associated with an enhanced expression of CXCR2 and Dectin-1 on bone marrow phagocytes. We also show that protective lung cytokine and chemokine responses are induced more rapidly and with enhanced dynamics in protected mice. Our findings support the hypothesis that following a first encounter with a non-lethal dose of A. fumigatus conidia, the innate immune system is primed and can mediate protection against a secondary lethal infection.  相似文献   
16.
Copper may be involved in the pathophysiology of depression. Clinical data on this issue are very limited and not conclusive. The purpose of the study was to determine the copper concentration in the serum of patients with major depressive disorder and to discuss its potential clinical usefulness as a biomarker of the disease. A case–control clinical study included 69 patients with current depressive episode, 45 patients in remission and 50 healthy volunteers. Cu concentration was measured by electrothermal atomic absorption spectrometry (ETAAS). The mean serum copper level in depressed patients was slightly lower (by 11 %; not statistically significant) than in the control group. Furthermore, there was no significant difference in Cu2+ concentration between depressive episode and remission, nor between remission and control group. In the remission group were observed significant correlations between copper levels and the average number of relapses over the past years or time of remission. There was no correlation between serum copper and severity of depression, as measured by HDRS and MADRS. The obtained results showed no significant differences between the copper concentration in the blood serum of patients (both with current depressive episode and in remission) and healthy volunteers, as well as the lack of correlations between the copper level in the active stage of the disease and clinical features of the population. Our study is the first conducted on such a large population of patients, so the results may be particularly important and reliable source of knowledge about the potential role of copper in depression.  相似文献   
17.
Risk and essential elements were determined in fruiting bodies of wild growing edible mushrooms Chlorophyllum rhacodes, Suillus grevillei, Imleria badia, and Xerocomellus chrysenteron collected in an unpolluted site in South Bohemia, the Czech Republic. The elements were also determined in underlying soils and the bioconcentration factors were calculated. The analyses revealed that C. rhacodes accumulated Ag, Cu, Rb, Se, Zn, As, Cd, and Tl. On the other hand, S. grevillei accumulated Cd, Rb, Ag, Se, and Cs. I. badia and X. chrysenteron strongly accumulated Rb, Cs, and Ag; these species showed the ability to accumulate Cu and Zn as well. Contents of detrimental CrVI were in all cases below the quantification limit (0.003 mg kg?1 dry matter). Studied mushroom species (mainly C. rhacodes) accumulated some toxic elements. However, no considerable effect on human health is expected since they are usually consumed as a delicacy and do not represent a major component of diet.  相似文献   
18.
To characterize the impact of the potentially functional mutation--the G to A transition at the position 3400 of the leukemia inhibitory factor (LIF; a pluripotent cytokine that plays a central role in the control of the embryo implantation) gene that leads to the exchange of valine with methionine at codon 64 we evaluated the association of the LIF gene mutation and the levels of antiphospolipid antibodies (aPLs) in the peripheral blood of infertile women (the aPLs examination was part of our routine immunological test during the infertility check-up). Eight infertile mutation-positive women were diagnosed with idiopathic infertility (n=5) and endometriosis (n=3) and their levels of aPLs in serum were compared with 115 infertile women without any LIF gene mutation. Enzyme-linked immunosorbent assay was used for the detection of seven antiphospholipid antibodies; the results were statistically assessed by the Fisher's 2 by 2 exact test to evaluate the association of the LIF gene mutations and aPLs in serum of infertile patients. The presence of aPLs was significantly higher in our study group (100%) than in 30% of aPLs-positives in control infertile patients (p = 0.0035) which indicates that the aPLs are elevated in women with LIF gene mutations.  相似文献   
19.

Background

Because lymphatic filariasis (LF) elimination efforts are hampered by a dearth of economic information about the cost of mass drug administration (MDA) programs (using either albendazole with diethylcarbamazine [DEC] or albendazole with ivermectin), a multicenter study was undertaken to determine the costs of MDA programs to interrupt transmission of infection with LF. Such results are particularly important because LF programs have the necessary diagnostic and treatment tools to eliminate the disease as a public health problem globally, and already by 2006, the Global Programme to Eliminate LF had initiated treatment programs covering over 400 million of the 1.3 billion people at risk.

Methodology/Principal Findings

To obtain annual costs to carry out the MDA strategy, researchers from seven countries developed and followed a common cost analysis protocol designed to estimate 1) the total annual cost of the LF program, 2) the average cost per person treated, and 3) the relative contributions of the endemic countries and the external partners. Costs per person treated ranged from $0.06 to $2.23. Principal reasons for the variation were 1) the age (newness) of the MDA program, 2) the use of volunteers, and 3) the size of the population treated. Substantial contributions by governments were documented – generally 60%–90% of program operation costs, excluding costs of donated medications.

Conclusions/Significance

MDA for LF elimination is comparatively inexpensive in relation to most other public health programs. Governments and communities make the predominant financial contributions to actual MDA implementation, not counting the cost of the drugs themselves. The results highlight the impact of the use of volunteers on program costs and provide specific cost data for 7 different countries that can be used as a basis both for modifying current programs and for developing new ones.  相似文献   
20.
Mycoheterotrophic species (i.e., achlorophyllous plants obtaining carbon from their mycorrhizal fungi) arose many times in evolution of the Neottieae, an orchid tribe growing in forests. Moreover, chlorophyllous Neottieae species show naturally occurring achlorophyllous individuals. We investigated the fungal associates of such a member of the Neottieae, Epipactis microphylla, to understand whether their mycorrhizal fungi predispose the Neottieae to mycoheterotrophy. Root symbionts were identified by sequencing the fungal ITS of 18 individuals from three orchid populations, including achlorophyllous and young, subterranean individuals. No rhizoctonias (the usual orchid symbionts) were recovered, but 78% of investigated root pieces were colonized by Tuber spp. Other Pezizales and some Basidiomycetes were also found. Using electron microscopy, we demonstrated for the first time that ascomycetes, especially truffles, form typical orchid mycorrhizae. All identified fungi (but one) belonged to taxa forming ectomycorrhizae on tree roots, and four of them were even shown to colonize surrounding trees. This is reminiscent of mycoheterotrophic orchid species that also associate with ectomycorrhizal fungi, although with higher specificity. Subterranean and achlorophyllous E. microphylla individuals thus likely rely on tree photosynthates, and a partial mycoheterotrophy in individuals plants can be predicted. We hypothesize that replacement of rhizoctonias by ectomycorrhizal symbionts in Neottieae entails a predisposition to achlorophylly.  相似文献   
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