MicroRNA-dependent metamorphosis in hemimetabolan insects
MicroRNA-dependent metamorphosis in hemimetabolan insects
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DOI：
10.1073/pnas.0907391106
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发表时间：
2009-12-22
影响因子：
11.1
通讯作者：
Belles, Xavier
中科院分区：
文献类型：
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作者：
Gomez-Orte, Eva;Belles, Xavier
一只幼年昆虫是如何变成成虫的？这个问题概括了昆虫变态的奇妙之处，自古以来就令人类着迷。现代生理学已经建立了调节这些转化的内分泌基础，这些转化主要取决于两种激素类型：促进蜕皮的蜕皮激素和抑制向成年阶段转化的保幼激素。这两种激素的相互作用调节着青少年和成年人的基因，以及从一种到另一种的转变。microRNAs（miRNAs）是一类非编码的小分子RNA，参与多种生物学过程，我们想知道它们是否也参与了昆虫的变态过程。在昆虫中，Dicer-1核糖核酸酶将miRNA前体转化为成熟的miRNA。因此，我们利用系统性RNA干扰（RNAi）来沉默半变态昆虫德国小蠊中Dicer-1的表达，从而耗尽末龄若虫中的miRNA含量。这实际上抑制了下一次蜕皮后的变态，因为所得到的标本显示若虫的特征，并能够再次蜕皮。实验表明，miRNAs在半变态中起着关键作用，可能调节保幼激素靶基因。
How does a juvenile insect transform into an adult? This question, which sums up the wonder of insect metamorphosis, has fascinated mankind since ancient times. Modern physiology has established the endocrine basis regulating these transformations, which mainly depend on two hormone types: ecdysteroids, which promote molts, and juvenile hormones, which repress the transformation into the adult stage. The interplay of these two hormones regulates the genes involved in juvenile and adult programs and the shift from one to the other. microRNAs (miRNAs) are small noncoding RNAs, which participate in many biological processes, and we wondered whether they might be also involved in insect metamorphosis. In insects, Dicer-1 ribonuclease transforms miRNA precursors into mature miRNAs. Thus, using systemic RNA interference (RNAi) to silence the expression of Dicer-1 in the hemimetabolan insect Blattella germanica, we depleted miRNA contents in the last instar nymph. This practically inhibited metamorphosis after the next molt, as the resulting specimens showed nymphoid features and were able to molt again. The experiments show that miRNAs play a key role in hemimetabolan metamorphosis, perhaps regulating genes that are juvenile hormone targets.