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The retrovirus frequently isolated from patients with the acquired immune deficiency syndrome (AIDS) has two novel open reading frames previously designated "A" and "B." The "A" region was found to be specifically expressed as polyadenylated RNA's of 5.5 and 5.0 kilobases in infected cells. The "B" region was expressed as 1.8- to 2.0-kilobase RNA species. Additional full-length and spliced messenger RNA's of the env region were also identified.  相似文献   
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Nef protein of HIV-1 is a transcriptional repressor of HIV-1 LTR   总被引:73,自引:0,他引:73  
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‘Candidatus Liberibacter solanacearum’ (Lso) is a bacterium that infects solanaceous crops and causes plant decline and yield losses, especially in potato and tomato. Lso is transmitted to these hosts by the potato psyllid (Bactericera cockerelli Sulc) vector. B. cockerelli host plants are not limited to crop plants, but also include many wild, solanaceous weeds. These wild hosts could potentially impact overwintering and breeding of the psyllids and serve as reservoirs for Lso. In the Pacific Northwestern United States, B. cockerelli was recently reported to overwinter on bittersweet nightshade (Solanum dulcamara L.). The present study utilized high resolution melting analysis of the B. cockerelli mitochondrial cytochrome c oxidase I gene to assess the psyllid populations occurring on S. dulcamara during the summer and winter months in Washington, Oregon, and Idaho. This technique has previously been used to analyze the cytochrome c oxidase I gene of B. cockerelli, and has identified four psyllid haplotypes. Lso infection was also determined for the psyllids collected from S. dulcamara. During both the summer and the winter months in the Pacific Northwest, the Northwestern psyllid haplotype was the predominant population found living on S. dulcamara. However, low levels of the Western psyllid population were also present in Washington and Oregon during the same period. No overwintering psyllids tested were Lso-infected, suggesting that these populations do not pose an imminent threat of Lso transmission to newly emerging potatoes and other solanaceous crops in the region, unless a source of Lso becomes available.  相似文献   
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