Miller Gabriel A, Islam M Saiful, Claridge Timothy D W, Dodgson Tim, Simpson Stephen J
School of Biological Sciences, The University of Sydney, Heydon-Laurence Building A08, NSW 2006, Australia.
J Exp Biol. 2008 Feb;211(Pt 3):370-6. doi: 10.1242/jeb.013458.
Depending on their rearing density, female desert locusts Schistocerca gregaria epigenetically endow their offspring with differing phenotypes. To identify the chemical basis for such maternal transmission, we compared solitarious and gregarious locust egg pod foam using high performance liquid chromatography (HPLC). We revealed causal relationships between foam chemistry and hatchling phenotype (phase state) by iteratively applying HPLC fractions from gregarious locust egg foam extracts to solitarious eggs and assessing resulting hatchlings with a behavioural bioassay involving logistic regression. Selection and application of increasingly specific HPLC fractions allowed us to isolate compounds with gregarizing properties. Hatchling gregarization was triggered only by certain fractions and was dose dependent. In a final series of experiments, we characterized the most specific gregarizing fraction by nuclear magnetic resonance (NMR) spectroscopy. Here we present tentative structural features of the primary locust maternal gregarizing agent, which appears to be an alkylated l-dopa analogue. In addition, we propose a mechanism for phase-dependent regulation of this compound's activity.
根据饲养密度的不同，雌性沙漠蝗虫（Schistocerca gregaria）会通过表观遗传赋予其后代不同的表型。为了确定这种母系传递的化学基础，我们使用高效液相色谱法（HPLC）比较了散居型和群居型蝗虫的卵荚泡沫。通过将群居型蝗虫卵泡沫提取物的HPLC馏分反复应用于散居型卵，并使用涉及逻辑回归的行为生物测定法评估孵化出的幼虫，我们揭示了泡沫化学与孵化幼虫表型（相态）之间的因果关系。选择并应用越来越特异的HPLC馏分使我们能够分离出具有群居化特性的化合物。孵化幼虫的群居化仅由某些馏分触发，并且呈剂量依赖性。在最后一系列实验中，我们通过核磁共振（NMR）光谱对最特异的群居化馏分进行了表征。在此，我们展示了主要蝗虫母体群居化剂的初步结构特征，它似乎是一种烷基化的左旋多巴类似物。此外，我们提出了一种该化合物活性的相依赖调节机制。
