家蚕核型多角体病毒基因polh的诱变分析

曾报道经化学诱变剂ＭＭＣ、９－ＡＡ和ＥＭＳ诱变的家蚕核型多角体病毒（ＢｍＮＰＶ）多角体形态出现异常,继代分离的诱变ＢｍＮＰＶ基因组对ＥｃｏＲＩ、ＢｇｌＩＩ和ＢａｍＨＩ的酶切谱发生变化。研究进一步揭示,诱变ＢｍＮＰＶ的多角体外层蛋白晶格排列呈现紊乱;多角体蛋白的ＳＤＳ－ＰＡＧＥ电泳谱与对照组比较有显著差异;对多角体蛋白基因ｐｏｌｈ的测序结果显示,３组诱变ＢｍＮＰＶ的ｐｏｌｈ基因发生了多处碱基（氨基酸     

马尾松毛虫核型多角体病毒包涵体的表面增强拉曼光谱研究

获得了马尾松毛虫核型多角体病毒（ＤｐＮＰＶ）包涵体在Ａｇ胶中的ＳＥＲＳ谱。包涵体是通过膜蛋白的ＣＯＯ－和ＮＨ２基团吸附在Ａｇ表面上,Ｔｒｐ和Ｐｈｅ残基侧链接近Ａｇ表面,Ｔｙｒ残基侧链远离Ａｇ表面,ＳＥＲＳ谱中没出现ＡｍｉｄｅⅠ和ＡｍｉｄｅⅢ带。强的低波数谱带（２３８ｃｍ－１）的出现表明包涵体与Ａｇ表面发生了明显的化学吸附。     

家蚕核型多角体病毒中国株和日本株vp39基因的比较研究

以苜蓿丫纹夜蛾核型多角体病毒的核衣壳蛋白基因ｖｐ３９设计引物,用ＰＣＲ技术扩增了家蚕核型多角体病毒中国株（ＢｍＮＰＶ－Ｃｈ）－１．３ｋｂ片段并测定了其全序列长１２３０ｂｐ。推导的氨基酸３５１个,其与ＢｍＮＰＶ日本株（ＢｍＮＰＶ－Ｊａ）ｖｐ３９基因核苷酸序列同源性达９７．５％,氨基酸同源性达９７．１％。该片段在Ｅ．ｃｏｌｉＢＬ２１中诱导表达能产生分子量约为３８ｋＤ的特征性蛋白带,证明所扩增片段为Ｂｍ     

家蚕核型多角体病毒egt基因的结构和功能分析

以苜宿银纹夜蛾核型多角体病毒（ＡｃＭＮＰＶ）的ｅｇｔ基因作探针,从家蚕核型多角体病毒镇江株（ＢｍＮＰＶ ＺＪ－８）基因组中克隆了ｅｇｔ基因及其旁侧序列,作了该片段的酶切图谱;测定了ＢｍＮＰＶ ＺＪ－８ｅｇｔ基因序列。与ＡｃＭＮＰＶ的ｅｇｔ基因相比同源性为９５％;基因大小都为１５１８ｂｐ。利用ｅｇｔ基因旁侧序列构建了转移载体ｐＵＤｅｇｔ,以绿色荧色光蛋白基因（ＥＧＦＰ）作报告基因取代ｅｇｔ基因,构建     

粘虫核型多角体病毒多角体蛋白基因结构和序列的研究

测定了粘虫核型多角体病毒（Ｌｅｕｃａｎｉａｓｅｐａｒａｔａｎｕｃｌｅａｒｐｏｌｙｈｅｄｒｏｓｉｓｖｉｒｕｓ,ＬｓＮＰＶ）两个ＥｃｏＲＶ片段的共１２０１ｂｐ序列,发现了一个７１４ｂｐ的开放阅读框（ＯＲＦ）,根据其与多种ＮＰＶ多角体蛋白基因（ｏｃｕ）同源性的比较和５＇端典型的１４ｂｐ保守序列,说明此ＯＲＦ即为ＬｓＮＰＶ的ｏｃｕ基因。根据核苷酸序列预测的多角体蛋白有２４６个氨基酸,其中酸性和碱性氨基酸数相等,疏水氨基酸含量很高,氨基酸组成中以谷氨酸（Ｇｌｕ）含量最高,谷氨酰胺和半胱氨酸含量最低。编码区碱基同源性与ＭｂＮＰＶ最高,为９７．０％;氨基酸同源性与ＭｂＮＰＶ最高,为９７．５％。密码子偏爱选用以第三个碱基为嘧啶的密码子。二级结构分析表明,α－螺旋（Ｈ）和β－折叠（Ｓ）相等,β－转角含量是Ｈ和Ｓ含量之和。     

牛疱疹病毒I型前早期基因BICPO的表达对牛免疫缺陷病毒LTR的反式激活…

由含有ＢＨＶ－１（Ｂｏｖｉｎｅ Ｈｅｒｐｅｓ Ｖｉｒｕｓ－１）前早期基因的基因组片段亚克隆ＩＣＰＯ（ＢＨＶ－１Ｉｎｆｅｃｔｅｄ Ｃｅｌｌ Ｐｒｏｔｅｉｎ Ｏ）的ＤＮＡ序列至表达载体ｐＳＶＤ３,构建质粒ｐＳＶ２．９。将该质粒与ＰＢＬＴＲ－Ｌｕｃ共转染小牛肺细胞,检测转染细胞裂解物的荧光素酶活性,ＢＩＣＰＯ的表达产物可以显著地激活ＢＩＶ ＬＴＲ启动子控制下的荧光素酶基因的表达。根据ＰＳＶ２．９与含有Ｂ     

木毒蛾核型多角体病毒形态结构及理化性质的研究

木毒蛾核型多角体病毒属昆虫杆状病毒科,核型多角体病毒属,多粒包埋型。在扫描电镜下,多角体呈不规则多面体,大小下一,平均直径为１．４μｍ,病毒粒子杆状,大小约为３９４×５６ｎｍ,经ＳＤＭ－ＰＡＧＥ分析,病毒多角体蛋白分子量为３０．５ｋＤ,病毒粒子结构蛋白由１９条多肽组成,分子量范围在８８－１７ｋＤ之间。多角体富含Ｇｌｕ、Ｖａｌ、Ｌｅｕ、而Ｃｙｓ、Ｍｅｔ、和Ｈｉｓ含量较少。其酸碱氨基酸之比为１．２６。病毒核酸为一环状ＤＮＡ,长度约为３８μｍ,经ＨｉｎｄⅢ、ＰｓｔⅠ、ＥｃｏＲⅠ和ＢｇｌⅠ单酶切以及ＢａｍＨⅠ＋ＨｉｎｄⅢ、ＢａｍＨⅠ＋ＰｓｔⅠ、ＢａｍＨⅠ＋ＢｇＩⅠ和Ｘｈｏｌ＋ＥｃｏＲⅠ双酶切分析,ＤＮＡ总分子量约为７１．６×１０￣６Ｄａｌｔｏｎｓ。     

中国棉铃虫核型多角体病毒DNA聚合酶基因的克隆和序列分析

应用谷实夜蛾核型多角体病毒（ＨｚＳＮＰＶ）ＤＮＡ聚合酶基因ＨｉｎｄⅢ／ＰｓｔⅠ３５９６ｂｐ片段作探针,经Ｓｏｕｒｔｈｅｒｎｂｌｏｔ杂交,克隆了中国棉铃虫核型多角体病毒（ＨａＳＮＰＶ）完整的ＤＮＡ聚合酶基因,大小约为３．４ｋｂ。限制性内切酶分析表明,ＨａＳＮＰＶＤＮＡ聚合酶基因限制性内切酶图谱与ＨｚＳＮＰＶ相似。用双脱氧链终止法测定该基因部分核苷酸序列（８０５ｂｐ）,推导出编码区２０６ａ。序列同源性比较显示,ＨａＳＮＰＶＤＮＡ聚合酶与ＨｚＳＮＰＶ之间具有高度的同源性;与ＬｄＭＮＰＶ、ＡｃＭＮＰＶ、ＢｍＳＮＰＶ、ＣｆＭＮＰＶ和ＯｐＭＮＰＶ也具有一定的同源性     

苜蓿丫纹夜蛾核型多角体病毒(AcMNPV)大立方形多角体突变株的分子生物学研究

利用空斑技术,从既能形成多角体又含ＴＫ酶基因的苜蓿丫纹夜蛾重组核型多角体病毒ＡｃＭＮＰＶ－ＴＫ中,纯化了一株形成大立方形多角体的病毒突变株ＡｃＭＮＰＶ－ＴＫｍｔ５１３。用ＥｃｏＲＩ、ＰｓｔⅠ、ＢｇｌⅡ及ＫｐｎⅠ等限制性内切酶对它做了酶切分析,并克隆了多角体蛋白全基因及其侧翼部分的片段。对所克隆的部分全序列测定结果,发现在多角体蛋白基因读码框内只出现了一个碱基的突变,导致了第２５位的氨基酸密码子由ＧＧＴ变为ＧＡＴ,该位氨基酸由甘氨酸（Ｇｌｙ）变为天冬氨酸（Ａｓｐｑ）还利用ＰＣＲ技术扩增出突变了的多角体蛋白基因部分片段,并将它克隆入转移载体质粒ｐＥＶ５５,与不形成多角体的重组病毒ＴｎＮＰＶ－ＨＢｓＤ４ＤＮＡ共转染Ｓｆ９细胞,结果产生同样的大立方形多角体病毒。     

复配型苜宿银纹夜蛾核型多角体病毒制剂双两种夜蛾的毒力测定

对防治蔬菜菜夜蛾（Ｓ）和斜纹夜蛾（ＰｒｏｄｅｎｉａｌｉｔｕｒａＦａｂｒｉｃｉｕｓ）为主并兼治菜螟、菜青虫、小菜蛾等鳞翅目害虫的单五型和复配型苜蓿银纹放蛾核型多角体病毒（ＡｕｔｏｇｒａｐｈａｃａｌｉｆｏｒｎｉｃａｎｕｃｈｌｅａｒｐｏｌｙｈｅｄｒｏｓｉｓＶｉｒｕｓ,ＡｃＭＮＰＶ）生物杀虫剂进行筛选。     

蓖麻蚕核型多角体病毒DNA转染四种昆虫细胞系的研究

用蓖麻蚕核型多角体病毒(PcrNPV)DNA转染草地贪夜蛾(SF)、家蚕(Bm)、斜纹夜蛾(SL)和菜粉蝶(Pr)四种昆虫细胞系,结果表明,PcrNPV DNA能在SF细胞内复制增殖并形成多角体,Pr细胞系对PcrNPV DNA转染不敏感;Bm和SL细胞出现病变症状,但在电镜下未观察到病毒粒子或多角体。     

苜蓿丫纹夜蛾杆状病毒在四个异源连续细胞系内的传代复制

本文比较了苜蓿丫纹夜蛾核多角体病毒(AcNPV)在贪食夜蛾IPLB-SF-21AE细胞及其克隆株IPLB-SF-21AEC细胞,棉铃虫SIE-HAH-806细胞和粘虫SIE-MSH-805细胞系内长期连续传代复制的情况,每代病毒复制的历程为7天,观察指标是,细胞内形成多角体的百分率,游离病毒粒子的TCID50,对幼虫活体感染性,以及受感染后细胞超微结构的变化,结果证实,AcNPV在异源IPLB-SF-21AE昆虫细胞系内连续复制至50代次后,依然具有正常的形态和感染性,这为在离体下长期有效地复制杆状病毒提供了可能,我们还发现,在离体系统内增殖的病毒,其正常形态和感染性的维持与选用敏感细胞的种类有关。     

家蚕（Bombyx mori）5龄幼虫丝腺染色质在核基质上的组构

家蚕(Bombyx mori)5龄幼虫丝腺的染色质高度多倍化,整个基因组达10~5至10~6个拷贝。依次经低盐和高盐抽提5龄幼虫中丝腺、后丝腺和蚕体的细胞核,得到其核晕 (nuclearhalo),限制性内切酶消化后还有一部分DNA片段与核基质紧密结合在一起,说明染色质的组织与核基质有关。通过测定核基质上残留的DNA片段的平均长度及其在全基因组DNA中所占的百分比计算出,核晕上DNAloop的平均大小在中丝腺、后丝腺以及蚕体细胞中均为67kb左右。丝腺中高度多倍化的染色质与二倍体蚕体组织之间并不存在差异,它们同样被错定在核基质上而分隔成长约67kb的染色质loop,从而保证整个基因组的有序排列。以丝素基因为探针进行DNA印迹杂交发现,在5龄后丝腺中丝素基因特异性地和核基质紧密结合,说明核基质与丝素基因的组织特异性表达有关。     

Characterization of mitochondrial genome of Chinese wild mulberry silkworm, Bomyx mandarina (Lepidoptera: Bombycidae)

The complete mitochondrial genome of Chinese Bombyx mandarina(ChBm) was determined.The cir-cular genome is 15682 bp long, and contains a typical gene complement, order, and arrangement iden-tical to that of Bombyx mori(B.mori) and Japanese Bombyx mandarina(JaBm) except for two addi-tional tRNA-like structures:tRNASer(TGA)-like and tRNAIle(TAT)-like.All protein-coding sequences are initi-ated with a typical ATN codon except for the COI gene, which has a 4-bp TTAG putative initiator codon.Eleven of 13 protein-coding genes(PCGs) have a complete termination codon(all TAA), but the re-maining two genes terminate with incomplete codons.All tRNAs have the typical clover-leaf structures of mitochondrial tRNAs, with the exception of tRNASer(TGA)-like, with a four stem-and-loop structure.The length of the A T-rich region of ChBm is 484 bp, shorter than those of JaBm(747 bp) and B.mori(494―499 bp).Phylogenetic analysis among B.mori, ChBm, JaBm, and Antheraea pernyi(Anpe) showed that B.mori is more closely related to ChBm than JaBm.The earliest divergence time estimate for B.mori-ChBm and B.mori-JaBm is about 1.08±0.18―1.41±0.24 and 1.53±0.20―2.01±0.26 Mya, respec-tively.ChBm and JaBm diverged around 1.11±0.16―1.45±0.21 Mya.     

Variations of hydrogen peroxide and catalase expression in Bombyx eggs during diapause initiation and termination

For diapause eggs of the silkworm, Bombyx mori, diapause initiation is prevented with hydrochloric acid (HCl) at around 20 h post-oviposition while diapause status is terminated with chilling around 5°C. To investigate whether hydrogen peroxide (H(2)O(2)) and catalase expression are involved in diapause initiation and termination, the concentration of H(2)O(2), relatively higher levels of catalase mRNA and activity of catalase were compared between (1) 20-h-old diapause eggs and the HCl-treated diapause eggs, and (2) 10-day-old diapause eggs and the 5°C-chilled diapause eggs. Compared to diapause eggs, the HCl-treated eggs had significantly higher H(2)O(2) concentrations (up from approximately 1-3 μmol/g fresh mass to 5-8 μmol/g fresh mass), higher relative level of catalase mRNA (up from 0 to 35.2%) and higher catalase activity (up from 2.51 units/mg protein to 4.97 units/mg protein) at 96 h post-treatment. On the other hand, the 5°C chilling resulted in significant increases of H(2)O(2) concentration (up from 0.79 μmol/g fresh mass to 5.57 μmol/g fresh mass), relative level of catalase mRNA (up from 0 to 71.4%) and catalase activity (up from 0.88 units/mg protein to 3.42 units/mg protein) within 120 days. The results obtained in this work suggest that variations of H(2)O(2) and catalase expression in Bombyx eggs are involved in diapause initiation and termination.     

Epizootiology of virus diseases in three lepidopterous insect species of alfalfa

Summary The incidence of virus infections in three lepidopterous insect species was studied from 1965 to 1968 in alfalfa fields in California. The insects were the alfalfa caterpillar,Colias eurytheme; the beet armyworm,Spodoptera exigua; and the alfalfa looper,Autographa californica. InC. eurytheme, the major virus was a nuclear polyhedrosis virus (NPV); inS. exigua, a granulosis virus (GV) and an NPV; inA. californica, a GV. Virus epizootics did not develop in very high densities ofC. eurytheme. Virus epizootics occurred in low host densities of the three insect species, especially in populations ofA. californica. The virus acted as a density-dependent factor in the regulation of the populations ofS. exigua andA. californica. Temperature, humidity and rainfall had no marked effect on the incidence of virus infections.