Changes in translatable mRNAs during the larval-pupal transformation of the epidermis of the tobacco hornworm.
Changes in translatable mRNAs during the larval-pupal transformation of the epidermis of the tobacco hornworm.
复制标题
烟草天蛾表皮幼虫-蛹转化过程中可翻译 mRNA 的变化。
DOI：
10.1016/0012-1606(82)90179-8
复制
发表时间：
1982
影响因子：
2.7
通讯作者：
Riddiford,LM
中科院分区：
文献类型：
--
作者：
Riddiford,LM
在变态的开始时，暴露于蜕皮激素在保幼激素（JH）的情况下，鳞翅目表皮改变其承诺从一个幼虫分化的蛹分化。在此过程中，体内和体外的mRNA群体的变化都通过在mRNA依赖的兔网织红细胞裂解物系统中制备的翻译产物的一维SDS-凝胶电泳分析来跟踪。幼虫表皮细胞被发现失去其翻译的mRNA的幼虫表皮蛋白和幼虫特定的色素insecticyanin在承诺的变化，这些从来没有出现。对于I类表皮蛋白和insecticyanin，这种损失发生在暴露于蜕皮激素，每个具有不同的时间过程。与此相反，II类表皮的mRNA在此期间首先增加，然后也消失的时候，蛹committed.In体外这些mRNA出现在只有微量的响应20-羟基蜕皮激素（20-HE）。蛹提交的细胞（后期在徘徊阶段）含有三个低分子量的蛋白质，这是可沉淀的蛹表皮抗血清的mRNA。蛹表皮mRNA的其余部分是不翻译，直到第三天徘徊后，蛹角质层被沉积在蜕皮激素的蜕皮激增的时间。蛹定向细胞还具有至少一种新的非角质层mRNA，该mRNA编码34 K蛋白，并且在形成角质层的幼虫和蛹表皮细胞中均不存在。由于其在体外对20-HE的反应中的出现被JH抑制，因此被称为蛹承诺特异性蛋白。因此，在承诺的变化20-HE失活幼虫特异性基因不可逆地在一个连续的级联事件。大多数蛹特异性基因的激活需要随后暴露于更多的蜕皮激素。
At the initiation of metamorphosis when exposed to ecdysteroid in the absence of juvenile hormone (JH), the lepidopteran epidermis changes its commitment from one for larval differentiation to one for pupal differentiation. Changes in mRNA populations during this change bothin vivoandin vitrowere followed by a one-dimensional SDS-gel electrophoretic analysis of translation products made in a mRNA-dependent rabbit reticulocyte lysate system. The larval epidermal cell was found to lose its translatable mRNAs for larval cuticular proteins and the larval-specific pigment insecticyanin during the change in commitment; these never reappeared. For Class I cuticular proteins and for insecticyanin, this loss occurred during the exposure to ecdysteroid, each with a differing time course. By contrast, Class II cuticular mRNAs first increased during this time, then also disappeared by the time the cells were pupally committed.In vitrothese mRNAs appeared in only trace amounts in response to 20-hydroxyecdysone (20-HE). The pupally committed cell (late in the wandering stage) contained mRNAs for three low-molecular-weight proteins which were precipitable with the pupal cuticular antiserum. The remainder of the pupal cuticular mRNAs were not translatable until the third day after wandering, a time when pupal cuticle is being deposited in response to a molting surge of ecdysteroid. The pupally committed cell also had at least one new noncuticular mRNA which coded for a 34K protein and which was absent from both larval and pupal epidermal cells making cuticle. Since its appearance in response to 20-HEin vitrois repressed by JH, it is called a pupal commitment-specific protein. Thus, during the change of commitment 20-HE inactivates larval-specific genes irreversibly in a sequential cascade of events. The activation of most pupal-specific genes then requires a subsequent exposure to more ecdysteroid.