Ernst Ulrich R, Van Hiel Matthias B, Depuydt Geert, Boerjan Bart, De Loof Arnold, Schoofs Liliane
Functional Genomics and Proteomics Lab, KU Leuven, Naamsestraat 59, bus 2465, B-3000 Leuven, Belgium.
Functional Genomics and Proteomics Lab, KU Leuven, Naamsestraat 59, bus 2465, B-3000 Leuven, Belgium
J Exp Biol. 2015 Jan 1;218(Pt 1):88-99. doi: 10.1242/jeb.107078.
Insects are one of the most successful classes on Earth, reflected in an enormous species richness and diversity. Arguably, this success is partly due to the high degree to which polyphenism, where one genotype gives rise to more than one phenotype, is exploited by many of its species. In social insects, for instance, larval diet influences the development into distinct castes; and locust polyphenism has tricked researchers for years into believing that the drastically different solitarious and gregarious phases might be different species. Solitarious locusts behave much as common grasshoppers. However, they are notorious for forming vast, devastating swarms upon crowding. These gregarious animals are shorter lived, less fecund and transmit their phase characteristics to their offspring. The behavioural gregarisation occurs within hours, yet the full display of gregarious characters takes several generations, as does the reversal to the solitarious phase. Hormones, neuropeptides and neurotransmitters influence some of the phase traits; however, none of the suggested mechanisms can account for all the observed differences, notably imprinting effects on longevity and fecundity. This is why, more recently, epigenetics has caught the interest of the polyphenism field. Accumulating evidence points towards a role for epigenetic regulation in locust phase polyphenism. This is corroborated in the economically important locust species Locusta migratoria and Schistocerca gregaria. Here, we review the key elements involved in phase transition in locusts and possible epigenetic regulation. We discuss the relative role of DNA methylation, histone modification and small RNA molecules, and suggest future research directions.
昆虫是地球上最成功的生物类别之一，这体现在其庞大的物种丰富度和多样性上。可以说，这种成功部分归因于多型现象，即一种基因型能产生不止一种表型，许多昆虫物种都利用了这一特性。例如，在社会性昆虫中，幼虫的饮食会影响其发育成不同的等级；蝗虫的多型现象多年来一直误导研究人员，使他们认为截然不同的独居和群居阶段可能是不同的物种。独居蝗虫的行为与普通蚱蜢很相似。然而，它们因在聚集时形成巨大的、具有毁灭性的蝗群而声名狼藉。这些群居的蝗虫寿命较短，繁殖力较低，并将其阶段特征遗传给后代。行为上的群居化在数小时内就会发生，但群居特征的完全显现需要几代人的时间，向独居阶段的转变也是如此。激素、神经肽和神经递质会影响一些阶段特征；然而，所提出的任何机制都无法解释所有观察到的差异，尤其是对寿命和繁殖力的印记效应。这就是为什么最近表观遗传学引起了多型现象领域的关注。越来越多的证据表明表观遗传调控在蝗虫阶段多型现象中发挥作用。这在具有重要经济意义的蝗虫物种飞蝗和沙漠蝗中得到了证实。在这里，我们综述了蝗虫阶段转变中涉及的关键要素以及可能的表观遗传调控。我们讨论了DNA甲基化、组蛋白修饰和小RNA分子的相对作用，并提出了未来的研究方向。
