Cátedra Histología y Embriología Animal (FCNyM-UNLP), La Plata, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET-ARGENTINA), Buenos Aires, Argentina.
Sci Rep. 2020 Feb 20;10(1):3091. doi: 10.1038/s41598-020-59495-1.
Juvenile hormones (JHs) are sesquiterpenoids synthesized by the corpora allata (CA). They play critical roles during insect development and reproduction. The first JH was described in 1934 as a "metamorphosis inhibitory hormone" in Rhodnius prolixus by Sir Vincent B. Wigglesworth. Remarkably, in spite of the importance of R. prolixus as vectors of Chagas disease and model organisms in insect physiology, the original JH that Wigglesworth described for the kissing-bug R. prolixus remained unidentified. We employed liquid chromatography mass spectrometry to search for the JH homologs present in the hemolymph of fourth instar nymphs of R. prolixus. Wigglesworth's original JH is the JH III skipped bisepoxide (JHSB3), a homolog identified in other heteropteran species. Changes in the titer of JHSB3 were studied during the 10-day long molting cycle of 4 instar nymph, between a blood meal and the ecdysis to 5 instar. In addition we measured the changes of mRNA levels in the CA for the 13 enzymes of the JH biosynthetic pathway during the molting cycle of 4 instar. Almost 90 years after the first descriptions of the role of JH in insects, this study finally reveals that the specific JH homolog responsible for Wigglesworth's original observations is JHSB3.
保幼激素（JH）是由前胸腺（CA）合成的倍半萜。它们在昆虫的发育和繁殖中起着关键作用。1934 年，Vincent B. Wigglesworth 爵士在 Rhodnius prolixus 中将第一种 JH 描述为“变态抑制激素”。值得注意的是，尽管 R. prolixus 作为恰加斯病的传播媒介和昆虫生理学的模式生物非常重要，但 Wigglesworth 为接吻虫 R. prolixus 描述的原始 JH 仍然未被识别。我们采用液相色谱-质谱联用技术来寻找 R. prolixus 四龄若虫血淋巴中存在的 JH 同系物。Wigglesworth 的原始 JH 是 JH III 缺失双环氧化物（JHSB3），这是在其他半翅目物种中鉴定出的同源物。在四龄若虫的 10 天蜕皮周期中，我们研究了 JHSB3 滴度在吸血和蜕皮到五龄之间的变化。此外，我们还测量了四龄蜕皮周期中 CA 中 13 种 JH 生物合成途径的酶的 mRNA 水平的变化。在 JH 对昆虫作用的首次描述近 90 年后，本研究终于揭示了负责 Wigglesworth 原始观察结果的特定 JH 同系物是 JHSB3。
