Juvenile hormone biosynthesis in adult Blattella germanica requires nuclear receptors Seven-up and FTZ-F1.
Juvenile hormone biosynthesis in adult Blattella germanica requires nuclear receptors Seven-up and FTZ-F1.
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DOI：
10.1038/srep40234
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发表时间：
2017-01-11
影响因子：
4.6
通讯作者：
Martín D
中科院分区：
文献类型：
--
作者：
Borras-Castells F;Nieva C;Maestro JL;Maestro O;Belles X;Martín D
在昆虫中，从幼虫发育到成虫阶段的过渡是由咽侧体（CA）腺体合成的保幼激素（JH）控制的。而在最后一个少年龄期的无JH期触发变态和生长期的结束，这种激素的再现后，成虫蜕皮标志着生殖成年期的开始。尽管这种转变很重要，但控制这种转变的监管机制仍然大多不为人知。在这里，使用半代谢昆虫德国小蠊，我们表明，核激素受体七上-B（BgSvp-B）和富士tarazu因子1（BgFTZ-F1）在组织和阶段特异性激活成人CA JH-生物合成活性的重要作用。这两种因子在成年CA细胞中高度表达。此外，BgSvp-B或BgFTZ-F1的RNAi敲低导致成年动物在两个关键的JH依赖性生殖过程（卵黄发生和卵子发生）中完全阻断。我们表明，这种生殖障碍是由于JH生物合成的一个显着的损害，由于CA特异性减少的两个关键JH生物合成酶，3-羟基-3-甲基戊二酰辅酶A合成酶-1（BgHMG-S1）和HMG还原酶（BgHMG-R）的表达。我们的研究结果提供了深入了解的监管机制的具体变化CA腺必要的适当过渡到成年。
In insects, the transition from juvenile development to the adult stage is controlled by juvenile hormone (JH) synthesized from the corpora allata (CA) glands. Whereas a JH-free period during the last juvenile instar triggers metamorphosis and the end of the growth period, the reappearance of this hormone after the imaginal molt marks the onset of reproductive adulthood. Despite the importance of such transition, the regulatory mechanism that controls it remains mostly unknown. Here, using the hemimetabolous insect Blattella germanica, we show that nuclear hormone receptors Seven-up-B (BgSvp-B) and Fushi tarazu-factor 1 (BgFTZ-F1) have essential roles in the tissue- and stage-specific activation of adult CA JH-biosynthetic activity. Both factors are highly expressed in adult CA cells. Moreover, RNAi-knockdown of either BgSvp-B or BgFTZ-F1 results in adult animals with a complete block in two critical JH-dependent reproductive processes, vitellogenesis and oogenesis. We show that this reproductive blockage is the result of a dramatic impairment of JH biosynthesis, due to the CA-specific reduction in the expression of two key JH biosynthetic enzymes, 3-hydroxy-3-methylglutaryl coenzyme A synthase-1 (BgHMG-S1) and HMG-reductase (BgHMG-R). Our findings provide insights into the regulatory mechanisms underlying the specific changes in the CA gland necessary for the proper transition to adulthood.