检测HIV-1载量的荧光实时定量PCR技术的建立及其应用

准确测定HIV-1的前病毒载量和病毒载量的技术,在感染者预后和艾滋病患者药物治疗效果的评价以及艾滋病的其它研究方面,都具有十分重要的应用价值。以定量的HIV-1DNA和RNA为标准外参照,利用SYBRGreen荧光染料和GeneAmp5700 Sequence Detection System(5700系统),建立了测定HIV-1的前病毒载量和病毒载量的荧光实时定量PCR技术。以病毒感染细胞和培养上清为材料,测定了三种化合物(AZT,GL和WT)对细胞内的前病毒载量和培养上清中的病毒载量的抑制活性,并与合胞体形成抑制方法测定化合物抗病毒活性的结果进行了比较。根据病毒载量、前病毒载量和合胞体形成计算出的三种化合物的治疗指数均依次变小,提出以荧光实时定量PCR技术测定前病毒载量,会在评价药物在体内外根除或减少存在于CD4休止或记忆T淋巴细胞中的HIV-1前病毒方面有特别的价值。     

RÔLE DE L'EAU DE BOISSON SUR LA PRISE DE NOURRITURE SÈCHE ET LE DÉVELOPPEMENT OVARIEN DE LOCUSTA MIGRATORIA MIGRATORIOIDES

Pour déterminer la ration minimale d'eau nécessaire à la survie de Locusta migratoria migratorioides (R. et F.) adulte et les repercussions d'un stress hydrique prolongé sur le fonctionnement ovarien, nous avons séparé le facteur eau du facteur aliment en élevant les criquets de l'éclosion à l'âge adulte avec des germinations de blé lyophilisé, selon une technique décrite par Louveaux et al. (1980). Il est montré que la quantité d'aliments ingérée augmente avec la quantité d'eau bue (r = 0,91). La relation linéaire déterminée permet inversement, connaissant les quantités d'aliments ingérés, d'évaluer à 300 μl la ration quotidienne d'un criquet ayant un accès non limité à l'eau de boisson. Les femelles qui n'ont reçu que 50 μl d'eau par jour (j.) sont mortes avant le 9ème jour de traitement. La survie est assurée à partir de 100 μl/j. L'avancement de la vitellogenèse est également en relation avec la quantité d'eau absorbée quotidiennement. Aucun développement ovarien ne se produit jusqu'à 100 μl/j. Une vitellogenèse ralentie commence à partir de 150 μl/j. et elle devient normale à 300 μl/j. avec des pontes comparables à celles des témoins nourris de blé frais.     

First Description of Various Bacteria Resistant to Heavy Metals and Antibiotics Isolated from Polluted Sites in Tunisia

Environmental bacteria belonging to various families were isolated from polluted water collected from ten different sites in Tunisia. Sites were chosen near industrial and urban areas known for their high degree of pollution. The aim of this study was to investigate cross-resistance between heavy metals (HM), i.e., silver, mercury and copper (Ag, Hg, and Cu), and antibiotics. In an initial screening, 80 isolates were selected on ampicillin, and 39 isolates, retained for further analysis, could grow on a Tris-buffered mineral medium with gluconate as carbon source. Isolates were identified based on their 16S rRNA gene sequence. Results showed the prevalence of antibiotic resistance genes, especially all isolates harbored the bla_TEM gene. Some of them (15.38%) harbored bla_SHV. Moreover, several were even ESBLs and MBLs-producers, which can threaten the human health. On the other hand, 92.30%, 56.41%, and 51.28% of the isolates harbored the heavy metals resistance genes silE, cusA, and merA, respectively. These genes confer resistance to silver, copper, and mercury. A cross-resistance between antibiotics and heavy metals was detected in 97.43% of our isolates.     

OsDMI3‐mediated activation of OsMPK1 regulates the activities of antioxidant enzymes in abscisic acid signalling in rice

In rice, the Ca²⁺/calmodulin (CaM)‐dependent protein kinase (CCaMK) OsDMI3 has been shown to be required for abscisic acid (ABA)‐induced antioxidant defence. However, it is not clear how OsDMI3 participates in this process in rice. In this study, the cross‐talk between OsDMI3 and the major ABA‐activated MAPK OsMPK1 in ABA‐induced antioxidant defence was investigated. ABA treatment induced the expression of OsDMI3 and OsMPK1 and the activities of OsDMI3 and OsMPK1 in rice leaves. In the mutant of OsDMI3, the ABA‐induced increases in the expression and the activity of OsMPK1 were substantially reduced. But in the mutant of OsMPK1, the ABA‐induced increases in the expression and the activity of OsDMI3 were not affected. Pretreatments with MAPKK inhibitors also did not affect the ABA‐induced activation of OsDMI3. Further, a transient expression analysis in combination with mutant analysis in rice protoplasts showed that OsMPK1 is required for OsDMI3‐induced increases in the activities of antioxidant enzymes and the production of H₂O₂. Our data indicate that there exists a cross‐talk between OsDMI3 and OsMPK1 in ABA signalling, in which OsDMI3 functions upstream of OsMPK1 to regulate the activities of antioxidant enzymes and the production of H₂O₂ in rice.     

Age,sex and beauty: methodological dependence of age‐ and sex‐dichromatism in the great tit Parus major

Carotenoid‐based colour expression is frequently involved in sexual dichromatism, particularly in bird plumage, suggesting a role in sexual selection. Despite much work on expression of the carotenoid‐based ventral plumage coloration of the great tit (Parus major), which represents a popular model in evolution and ecology, a consensus on even the most basic demographic patterns of variation (e.g. age and sex differences) is lacking. This may reflect the use of variable methods for analysing colour variation, although what is not clear, either in this case or in general, is the extent to which these alternative methods are equally effective at describing age‐ and sex‐related dichromatism. Using data obtained over 4 years from a large sample of free‐ranging great tits, we examined how colour‐scoring methodology influences estimates of age‐ and sex‐related dichromatism. We compare: (1) principal components analysis‐derived scores; (2) tristimulus colour variables; (3) a visual model‐independent, carotenoid‐focussed colour score; and (4) two colour scoring methods based on avian visual models, examining how they assess colour variation with respect to age and sex to determine how methodology may influence results. We demonstrate clear age‐ and sex‐dependent expression of this colour trait, both in our own data and in meta‐analyses of results from great tit populations across Europe, and discuss the merits of the various colour scores, which yield very different estimates of the extent of age‐ and sex‐dependent dichromatism. We show variation is likely to be visible to conspecifics and propose a novel, visual model‐derived scoring system for describing variation in carotenoid‐based colour patches, where the perceived signal is divided into independent chromatic and achromatic components, in line with current understanding of visual perception. The present study highlights the impact of colour‐scoring methodology and shows that, as novel measures continue to be developed, researchers should consider carefully how they quantify colour expression. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 777–796.     

Long‐term relationship between diet breadth and breeding success in a declining population of Egyptian Vultures Neophron percnopterus

Between 2000 and 2009 we studied the diet and breeding success of Egyptian Vultures Neophron percnopterus in southern Spain. Wild species accounted for 74.9% of prey items (n = 1071) with a predominance of mammals (62.3%), followed by birds (20.8%) and reptiles (13.1%). Spatially, the diet was highly varied and not restricted to carcasses of livestock; wild Rabbits Oryctolagus cuniculus accounted for 54% of the overall remains. The spatial variability may reflect regional and local disparity in the availability of main prey. The temporal relationship between variation in trophic diversity and Vulture nesting productivity (both values showing a long‐term decrease) might suggest a causal link between variation in diet and reproductive output. We hypothesize that high turnover rates could explain productivity variation as a consequence of the recruitment of less experienced individuals to the breeding population. This could in turn generate covariation between diet and reproductive output.