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小木虫论坛-学术科研互动平台» 学术交流区» 论文翻译 » 论文翻译求助完结子版 » 求助一篇文章的翻译
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caitikuan

木虫 (小有名气)
According to the pore-formation model, the binding of protease-activated toxin to cadherin is essential for the removal of helix a-1, which in turn promotes oligomerization.
根据孔隙形成模型，蛋白酶激活的毒素结合钙粘蛋白过程中消除α-1螺旋是必不可少的，而这反过来又促进寡聚化作用。
Therefore, we hypothesized that modified Cry1Ab and Cry1Ac toxins lacking helix a-1 (referred to hereafter as Cry1AbMod and Cry1AcMod) could form oligomers without cadherin.
因此，我们推测改变后的Cry1Ab和Cry1Ac毒素缺乏α-1螺旋（以下简称为Cry1AbMod和Cry1AcMod ）可以形成无钙粘蛋白的低聚物。
To test this hypothesis, we compared oligomerization of native and modified Cry1Ab and Cry1Ac in the presence and absence of toxin-binding cadherin fragments.
为了验证这一假说，在存在和缺失毒素结合的钙粘蛋白片段中我们比较天然的和改变的Cry1Ab和Cry1Ac寡聚化作用。
Toxins were activated by trypsin to mimic the protease activation that occurs in the insect gut.
用胰蛋白酶激活毒素来模仿在昆虫肠道蛋白酶激活发生。
Previous work shows that trypsin-activated Cry1Ab forms 250-kD oligomers in the presence of Manduca sexta cadherin fragments containing toxin-binding regions corresponding to cadherin repeats 7 and 11 or a singlechain antibody (scFv73) that mimics these cadherin toxin-binding regions.
以往的工作表明，存在烟草天蛾中的胰蛋白酶激活Cry1Ab250 kD低聚物结构的钙粘蛋白片段含有毒素结合区域，该区域相应的钙粘蛋白重复7和11或单链抗体（ scFv73 ）。该抗体模仿这些钙粘蛋白毒素结合区域。
We found that trypsin activated Cry1Ab and Cry1Ac formed oligomers in the presence of a protein fragment corresponding to cadherin repeat 12 (CADR12), an important toxin-binding region (21), but not without cadherin or with cadherin repeat 9 (CADR9), a region that does not bind toxin.
我们发现，烟草天蛾体内胰蛋白酶激活Cry1Ab和Cry1Ac形成低聚物是在相应的钙粘蛋白重复12 （ CADR12 ）蛋白片段存在的情况下发生。CADR12，一个重要的毒素结合区（ 21 ） ，但并非没有钙粘蛋白或钙粘着蛋白重复9 （CADR9 ），一个不含毒素结合的区域。
In contrast, trypsin-activated Cry1AbMod and Cry1AcMod formed oligomers without cadherin, although not as efficiently as the wild type with CADR12.
与此相反，胰蛋白酶激活的Cry1AbMod和Cry1AcMod形成低聚物不含钙粘蛋白，导致其效率不如野生型CADR12 。
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11楼2009-01-15 13:27:32
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caitikuan

木虫 (小有名气)
We used RNA interference (RNAi) to reduce production of cadherin protein (Fig. 2 and fig. S1) and decrease the susceptibility of M. sexta larvae to Cry1Ab.
我们使用的RNA干涉（ RNAi ），以减少产生的钙粘蛋白（图2和图S1）和降低烟草天蛾幼虫对Cry1Ab的 易感性。
Larvae injected with either 1 mg of cadherin double-stranded RNA (dsRNA) or water only (control) ate a diet treated with 20 ng of Cry1Ab protoxin/cm2.
幼虫注射1毫克的钙粘蛋白的双链RNA 或水（对照），食物采用 20纳克的Cry1Ab protoxin/cm2 饮食治疗。
After 3 days, survival was 92% for 48 RNAi-treated larvae versus 0% for 48 control larvae (chi-square test, P < 0.001).
3天后，48 只RNA干扰治疗的幼虫存活92 ％，对照的48只存活率为0 ％（卡方检验， P <  0.001 ） 。
The next experiment showed that cadherin silenced M. sexta larvae were much more susceptible to Cry1AbMod than to Cry1Ab (fig. S2).
接着的试验表明，钙粘蛋白沉默的天蛾幼虫，对Cry1AbMod比对Cry1Ab更敏感 （图S2）。
Confirming the results described above, the survival of larvae fed a diet treated with 20 ng of Cry1Ab protoxin/cm2 was higher for 48 RNAi-treated larvae (92%) than for 48 control larvae (2%)(chi-squaretest, P < 0.001).
上述结果证实了，幼虫喂食饮食治疗20纳克的Cry1Ab protoxin/cm2的生存48只 RNA干扰治疗的幼虫（92 ％）高于48只对照幼虫（2 ％） （卡方检 p<0.001 ）。
However, on a diet with 5 ng of Cry1AbMod protoxin/cm2, 48 RNAi-treated larvae had only 2% survival, which is significantly lower than the aforementioned 92% survival of 48 RNAitreated larvae fed a diet treated with 20 ng of Cry1Ab protoxin/cm2 (chi-square test, P < 0.001).
然而，在喂食5纳克的Cry1AbMod protoxin/cm2 后，48 只RNA干扰治疗的幼虫只有2 ％的生存，这是显着低于上述48只 RNAitreated幼虫喂食饮食治疗20纳克的Cry1Ab protoxin /平方厘米的92 ％存活（卡方检验， P < 0.001 ） 。

我们还进行突变和野生型Cry1A毒素对幼虫的抗性品系（ AZP - R ）和敏感品系（APHIS-S）的棉花害虫红铃虫（棉红铃虫）的试验。在含Bt棉生产Cry1Ac试验中抗性品系幼虫幸存而非敏感品系幼虫。在AZP - R中抗Cry1Ac是与钙粘素受体基因缺失突变相关。抗性品系中Cry1AbMod和Cry1AcMod减弱或抵抗抗性（图3和表1）。在此基础上造成50 ％（半致死浓度）死亡的浓度，AZP - R相对APHIS-S， AZP - R比APHIS-S抗Cry1Ab>910倍和 抗Cry1Ac> 3700倍（表1）。与此相反，AZP - R只有2.8倍耐Cry1AbMod ，而不抗Cry1AcMod （表1）。对耐药性幼虫的LC50Cry1Ac比Cry1AbMod或Cry1AcMod 高为00倍以上（表1）。相反，对敏感的幼虫，天然毒素有效性超过了改变毒素。这意味着，相对于天然毒素作用于敏感幼虫，修饰毒素在中肠稳定性降低，低聚物形成能力降低（图1 ） ，或减少低聚物的能力，最终导致毒素无作用。

[ Last edited by caitikuan on 2009-1-15 at 14:42 ]
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12楼2009-01-15 13:45:37
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caitikuan

木虫 (小有名气)

最后两段

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xu_0501(金币+300,VIP+0):thank you very much
The results suggest that in two species of Lepidoptera, cadherin receptor
protein in the larval midgut mediates the toxicity of Cry1A toxins by
facilitating removal of helix a-1, which promotes toxin oligomerization.
结果表明，在2种鳞翅目昆虫中，钙粘蛋白受体蛋白在介导幼虫中肠Cry1A毒素的毒性，促进消除α-1螺旋，从而促进毒素寡聚化。
The modified toxins Cry1AbMod and Cry1AcMod lacking helix α-1 formed oligomers  in vitro without cadherin, whereas native Cry1Ab and Cry1Ac did not.
修改后的毒素Cry1AbMod和Cry1AcMod缺乏α - 1 螺旋，在体外形成低聚物无钙粘蛋白，而天然Cry1Ab和Cry1Ac在体外形成低聚物有钙粘蛋白。
The modified toxins killed insects with greatly reduced susceptibility to
native Cry1A toxins caused by RNAi silencing of the cadherin gene or by mutations in the cadherin gene.
修改后的毒素杀死昆虫的同时大大降低天然Cry1A毒素感性，这种降低是由昆虫适应性的RNAi沉默或基因突变钙粘蛋白的基因。
These results support the pore-formation model (15) and not the signaling
model, which does not include removal of helix a-1 or toxin oligomerization
.
这些结果支持孔隙形成模型，而不是信号模型，其中不包括消除螺旋级或毒素低聚化。



If the results seen here with the pink bollworm extend to other lepidopterans,Cry1AbMod and Cry1AcMod could be broadly useful for countering or delaying pest resistance to Cry1A toxins.
如果在这里看到的结果，能从红铃虫扩展到其他鳞翅类昆虫 ，Cry1AbMod和Cry1AcMod大致可用于解决或推迟害虫对Cry1A毒素抗药性。
However, we do not know whether Cry1AMod toxins kill insects with mechanisms of resistance unrelated to cadherin, such as the disruption of other receptors or decreased protease activation.
然而，我们不知道Cry1AMod毒素杀死害虫的抗性机制是否和钙粘蛋白无关，如其他受体蛋白酶激活的中断或减少。
Many Bt toxins have structural topology similar to Cry1A, form oligomers, and
induce pores, suggesting that they share a similar mode of action.
Bt毒素和Cry1A有许多相似如拓扑结构 ，在形成低聚物及诱导空隙的过程，这表明它们具有类似的作用方式。
It remains to be determined whether, parallel to results with Cry1A toxins,
other Cry toxins lacking helix a-1 can kill resistant insects that have altered
receptors.
Cry1A毒素与其他缺乏α-1螺旋的能够杀死改变受体且具有抗性的昆虫的Cry毒素结果是否平行还有待确定。
In addition, insects can probably evolve resistance to modified Bt toxins
lacking helix a-1.
此外，昆虫可能演变出抵抗修改的缺乏α-1螺旋的Bt毒素品系。
Nonetheless, along with native Bt toxins such as Cry2 and Vip3 that have not been used as extensively as Cry1A toxins, the modified toxins broaden the options for pest control.
然而，随着野生型Bt毒素，如Cry2和Vip3还没有被用来作为广泛的Cry1A毒素，扩大了毒素的修改选择范围来控制虫害。

[ Last edited by caitikuan on 2009-1-15 at 15:35 ]
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13楼2009-01-15 14:00:36
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sixmonths

铁杆木虫 (著名写手)

清歌一曲月如霜
引用回帖:
Originally posted by caitikuan at 2009-1-15 14:00:
The results suggest that in two species of Lepidoptera, cadherin receptor
protein in the larval midgut mediates the toxicity of Cry1A toxins by
facilitating removal of helix a-1, which promotes ...

lz 和 ls 真是感天动地 祝福
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今夜月明入尽望，不知秋思落谁家。
14楼2009-01-15 21:04:45
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