Recombinant Bacillus thuringiensis strain shows high insecticidal activity against Plutella xylostella and Leptinotarsa decemlineata without affecting nontarget species in the field

Aims: To construct a recombinant Bacillus thuringiensis (Bt) strain with broad insecticidal spectrum and investigate its impact on nontarget organisms in field. Method and Results: The cry-type gene of wild Bt strain UV17 was identified and a novel cry1Ba gene was cloned. The cry3Aa7 gene, which was highly toxic to coleopteran pests, was introduced into UV17, and a recombinant strain designated as UV173A was obtained. Bioassay results showed that UV173A was not only highly toxic against Plutella xylostella (50% lethal concentration [LC₅₀] = 18·03 μg ml^–1), but also against coleopteran Leptinotarsa decernlineata (LC₅₀ = 0·19 mg ml^–1). The recombinant strain was then tested in field trials to monitor its spatial variation of population and to investigate the impact on nontarget invertebrates. Conclusions: A recombinant Bt stain UV173A with broad insecticidal spectrum was obtained, and it did not cause adverse effects on the population of nontarget organisms. Significance and Impact of the Study: The results obtained here indicated that cry1Ba3 gene may be useful for the resistance management of P. xylostella, and the recombinant stain UV173A was potential for field application against some crucifer vegetable pests as well as L. decemlineata.     

番鸭呼肠孤病毒YB株σB蛋白的基因序列分析及其原核表达

番鸭呼肠孤病毒(Muscovy duck reovirus,DRV)是造成雏番鸭高死亡率的重要病原体,深入其检测与免疫研究对于防控DRV感染意义重大。利用RT-PCR和测序技术,对3株福建DRV分离株的S3基因进行序列分析,发现DRV-YH、YJL株与禽呼肠孤病毒(Avian reovirus,ARV)遗传距离较近,同源性高达94.6%～98.9%,而DRV-YB株与ARV同源性仅为60.6%～61.7%。构建和鉴定DRV YB株重组原核表达质粒pET-30a-S3,并转化大肠杆菌BL21,SDS-PAGE表明,表达的目的蛋白分子量约为42ku,IPTG最适诱导浓度为0.1mM,最适诱导时间为5h,最适诱导温度为37℃,以包涵体形式存在。薄层扫描显示重组DRVσB蛋白占菌体总量的67.7%。以Ni 2+柱亲和层析纯化蛋白,纯化后的目的蛋白纯度为93%,质量浓度为0.86g/L。Western blot分析该融合蛋白能与抗DRV阳性血清发生特异性反应,表明重组DRVσB蛋白具有良好的免疫反应性。     

甘蔗类异黄酮还原酶(IRL)基因的克隆与表达分析

采用RT-PCR技术从甘蔗中克隆So IRL基因,用生物信息学方法对获得的氨基酸序列进行分析,利用荧光定量PCR技术研究So IRL基因在甘蔗不同组织和不同胁迫条件下的表达特性。结果表明,克隆获得甘蔗So IRL,Gen Bank登录号为KF808324。该c DNA全长1 169 bp,含有1个927 bp的完整开放阅读框(ORF),编码309个氨基酸。系统进化树分析显示,甘蔗So IRL与玉米的IRL蛋白亲缘关系较近。q RT-PCR分析表明So IRL在甘蔗根、茎、叶中均有表达;在RSD病菌及低温(4℃)、聚乙二醇(PEG)、Na Cl和脱落酸(ABA)4种非生物胁迫下均被诱导表达,但表达模式不同。说明该基因可能参与甘蔗应答RSD过程,并可能在非生物胁迫中也发挥了作用。     

Variations in the C3, C3a receptor, and C5 genes affect susceptibility to bronchial asthma

Bronchial asthma (BA) is a common chronic inflammatory disease characterized by hyperresponsive airways, excess mucus production, eosinophil activation, and the production of IgE. The complement system plays an immunoregulatory role at the interface of innate and acquired immunities. Recent studies have provided evidence that C3, C3a receptor, and C5 are linked to airway hyperresponsiveness. To determine whether genetic variations in the genes of the complement system affect susceptibility to BA, we screened single nucleotide polymorphisms (SNPs) in C3, C5, the C3a receptor gene (C3AR1), and the C5a receptor gene (C5R1) and performed association studies in the Japanese population. The results of this SNP case-control study suggested an association between 4896C/T in the C3 gene and atopic childhood BA (P=0.0078) as well as adult BA (P=0.010). When patient data were stratified according to elevated total IgE levels, 4896C/T was more closely associated with adult BA (P=0.0016). A patient-only association study suggested that severity of childhood BA was associated with 1526G/A of the C3AR1 gene (P=0.0057). We identified a high-risk haplotype of the C3 gene for childhood (P=0.0021) and adult BA (P=0.0058) and a low-risk haplotype for adult BA (P=0.00011). We also identified a haplotype of the C5 gene that was protective against childhood BA (P=1.4×10^–6) and adult BA (P=0.00063). These results suggest that the C3 and C5 pathways of the complement system play important roles in the pathogenesis of BA and that polymorphisms of these genes affect susceptibility to BA.     

An improved transformation protocol for studying gene expression in hairy roots of sugar beet (Beta vulgaris L.)

A transformation protocol, based on co-inoculation with two strains of Agrobacterium, Agrobacterium tumefaciens LBA4404 and A. rhizogenes 15834 containing a binary vector with the GUS gene, was established for the induction of transgenic hairy roots from sugar beet (Beta vulgaris L.) explants. It resulted in marked improvement in the formation of hairy roots and the integration of the binary vector T-DNA into the host genome. Of 250 inoculated sugar beet hypocotyls, 84% yielded hairy roots 5–7 days after inoculation, of which 70% were co-transformed with the binary vector T-DNA. To determine stable expression of alien genes in hairy roots, the nematode resistance gene Hs1 ^pro-1 was used as a reporter gene. In addition, molecular marker analysis was applied to monitor stable incorporation of a translocation from the wild beet B. procumbens. The molecular analysis and the nematode (Heterodera schachtii) resistance test in vitro demonstrated that the genomic structure and the expression of the Hs1 ^pro-1 -mediated nematode resistance were well-maintained in all hairy root cultures even after repeated sub-culture. Received: 25 November 1997 / Revision received: 26 May 1998 / Accepted: 15 June 1998     

白化病的遗传流行病学研究

本文应用分离分析和血缘分析方法,对山东省１００余万人群遗传病调查中发现的３７个白化病核心家系进行了分析。结果表明：白化病存在遗传异质性,为多基因常染色体隐性遗传,最小基因数为８,平均基因频率为０．００２３,群体中致病基因携带者频率为０．０３８３;近亲结婚大大提高白化病的患病率。     

Dynamic patterns of histone H3 lysine 4 methyltransferases and demethylases during mouse preimplantation development

Extensive and dynamic chromatin remodeling occurs after fertilization, including DNA methylation and histone modifications. These changes underlie the transition from gametic to embryonic chromatin and are thought to facilitate early embryonic development. Histone H3 lysine 4 methylation (H3K4me) is an important epigenetic mechanism that associates with gene-specific activation and functions in development. However, dynamic regulation of H3K4me during early embryonic development remains unclear. Herein, the authors examined the dynamic changes of H3K4me and its key regulators (Ash1l, Ash2l, Kmt2a, Kmt2b, Kmt2c, Setd1a, Setd7, Kdm1a, Kdm1b, Kdm5a, Kdm5b, Kdm5c, and Kdm5d) in mouse oocytes and preimplantation embryos. An increase in levels of H3K4me2 and me3 was observed at the one- to two-cell stages (P?P?P?相似文献   

子宫颈糜烂病毒病因的探讨

491份宫颈拭子病毒分离结果表明:糜烂宫颈单纯疱疹病毒(HSV)分离阳性率(30.8％)是正常宫颈(2.6％)的11.8倍,用人干扰素治疗一个疗程后,病毒分离率下降至疗前的1/4.36例糜烂宫颈活体组织DNA分子杂交表明,乳头瘤病毒16型(HPV-16)阳性者占52.8和,HPV-18占17.9％,HPV-6B占28.1％,HPV-11占7.7％,251例宫颈糜烂患者经人(?)D型基因工程干扰素双盲对比治疗后,总有效率达93.8％,显效率达60％,分析临床疗效与HSV分离率的变化表明,临床有效病例中有35％(49/140)在治疗后病毒阴转,有57％在疗前疗后均未分离出HSV,有5％在疗前疗后保持阳性不变,有2.9％疗前阴性,疗后阳性,上述结果表明,HSV和HPV与慢性宫颈炎有一定关系。     

Energy intake and adiponectin gene expression

Hypoadiponectinemia and decreased adiponectin gene expression in white adipose tissue (WAT) have been well observed in obese subjects and animal models. However, the mechanism for obesity-associated hypoadiponectinemia is still largely unknown. To investigate the regulatory role of energy intake, dietary fat, and adiposity in adiponectin gene expression and blood adiponectin level, a series of feeding regimens was employed to manipulate energy intake and dietary fat in obese-prone C57BL/6, genetically obese ob/ob, obese-resistant A/J and peroxisome proliferator-activated receptor-α gene knockout (PPARα KO) mice. Adiponectin gene expression in WAT and circulating adiponectin levels were studied in these dietary intervention-treated mice. Our study showed that calorie restriction (CR) robustly increased adiponectin gene expression in epididymal fat and blood adiponectin levels in both low-fat (LF) and high-fat (HF) diet-fed C57BL/6 mice. Although HF pair-fed C57BL/6 mice received the same amount of calories as LF ad libitum-fed mice, HF diet clearly increased adiposity but showed no significant effects on adiponectin gene expression and blood adiponectin level. CR also significantly increased blood adiponectin levels in ob/ob and A/J mice. Neither CR nor HF feeding displayed any significant effect on blood adiponectin half-life in C57BL/6 mice. Interestingly, CR increased PPARα expression in epididymal fat of C57BL/6 mice. Low levels of blood adiponectin and adiponectin gene expression in WAT were observed in PPARα KO mice. PPARα agonist treatment increased adiponectin mRNA levels in 3T3-L1 adipocytes. Furthermore, CR failed to increase adiponectin gene expression and blood adiponectin levels in PPARα KO mice. Therefore, our study demonstrated that energy intake, not dietary fat, plays an important role in regulating adiponectin gene expression and blood adiponectin level. PPARα mediates CR-enhanced adiponectin gene expression in WAT.