Institut für Biologie, Freie Universität Berlin, Berlin, Germany.
Arch Insect Biochem Physiol. 2010 Jul;74(3):135-46. doi: 10.1002/arch.20359.
The genome of Tribolium castaneum encodes two allatostatin [AS type B; W(X)(6)Wamide and AS type C; PISCF-OH] and one allatotropin (AT) precursor, but no AS type A (FGLamide) (Tribolium Genome Sequencing Consortium, 2008: Nature 452:949-955). Here we studied the activity (in vitro) of peptides derived from these precursors on the synthesis/release of juvenile hormone (JH) III. The corpora cardiaca-corpora allata (CC-CA) complexes of adult females of another tenebrionid beetle, the mealworm Tenebrio molitor, were used. Incubating the gland complexes in a medium containing Trica-AS B3 peptide, we showed that the peptide has allatostatic function in T. molitor. The activity of the type C AS depended on the age of the test animals and their intrinsic rate of JH III biosynthesis. The Trica-AS C peptide inhibited the JH release from CA of 3-day-old females with a high intrinsic rate of JH synthesis, but activated JH release from the CA of 7-day-old females with a lower intrinsic rate of JH production. The allatotropin peptide (Trica-AT) also activated the JH release from the CA of 7-day-old females in a dose-dependent and reversible manner. Unexpectedly, a type A AS derived from the precursor of the American cockroach Periplaneta americana (Peram-AS A2b) inhibited the JH release from the CA of younger and older females in the concentration range of 10(-8) to 10(-4) M, and the effects were fully reversible in the absence of peptide. These data suggest a complex role of allatoactive neuropeptides in the regulation of JH III biosynthesis in beetles.
沟胫天牛（Tribolium castaneum）的基因组编码了两种脑肠肽[AS 型 B；W(X)(6)Wamide 和 AS 型 C；PISCF-OH]和一种促前胸腺激素（AT）前体，但没有 AS 型 A（FGLamide）（沟胫天牛基因组测序联盟，2008：自然 452:949-955）。在这里，我们研究了这些前体衍生肽在保幼激素（JH）III 合成/释放中的活性（体外）。我们使用了另一种隐翅甲科甲虫，黄粉虫（Tenebrio molitor）的成体雌虫的心-咽侧体复合体（CC-CA）。在含有 Trica-AS B3 肽的培养基中孵育腺复合体，我们表明该肽在 T. molitor 中具有抗促前胸腺激素活性。C 型 AS 的活性取决于测试动物的年龄及其内在 JH III 生物合成率。Trica-AS C 肽抑制具有高内在 JH 合成率的 3 日龄雌性 CA 中的 JH 释放，但激活具有较低内在 JH 产生率的 7 日龄雌性 CA 中的 JH 释放。AT 肽（Trica-AT）也以剂量依赖和可逆的方式激活 CA 中 JH 的释放。出乎意料的是，源自美洲大蠊（Periplaneta americana）前体的 A 型 AS 肽（Peram-AS A2b）在 10(-8)至 10(-4)M 的浓度范围内抑制了年轻和年老雌性 CA 中 JH 的释放，并且在没有肽的情况下，这些作用是完全可逆的。这些数据表明，在甲虫中，促前胸腺激素活性神经肽在 JH III 生物合成的调节中具有复杂的作用。
