Saenko Suzanne V, Chouteau Mathieu, Piron-Prunier Florence, Blugeon Corinne, Joron Mathieu, Llaurens Violaine
1Institut de Systématique, Evolution et Biodiversité, UMR 7205 (CNRS, MNHN, Sorbonne Université, EPHE), Muséum National d'Histoire Naturelle CP50, 57 rue Cuvier, 75005 Paris, France.
2Laboratoire Ecologie, Evolution, Interactions Des Systèmes Amazoniens (LEEISA), USR 3456, CNRS Guyane, Université De Guyane, 275 route de Montabo, 97334 Cayenne, French Guiana.
Evodevo. 2019 Aug 8;10:16. doi: 10.1186/s13227-019-0129-2. eCollection 2019.
Unravelling the genetic basis of polymorphic characters is central to our understanding of the origins and diversification of living organisms. Recently, supergenes have been implicated in a wide range of complex polymorphisms, from adaptive colouration in butterflies and fish to reproductive strategies in birds and plants. The concept of a supergene is now a hot topic in biology, and identification of its functional elements is needed to shed light on the evolution of highly divergent adaptive traits. Here, we apply different gene expression analyses to study the supergene that controls polymorphism of mimetic wing colour patterns in the neotropical butterfly .
We performed de novo transcriptome assembly and differential expression analyses using high-throughput Illumina RNA sequencing on developing wing discs of different morphs. Within the interval, 30 and 17 of the 191 transcripts were expressed differentially in prepupae and day-1 pupae, respectively. Among these is the gene , known to play a role in wing pattern formation in and other Lepidoptera. Our in situ hybridization experiments confirmed the relationship between expression and adult wing patterns.
This study found the majority of genes in the interval to be expressed in the developing wing discs during the critical stages of colour pattern formation, and detect drastic changes in expression patterns in multiple genes associated with structural variants. The patterns of expression of only partially recapitulate the variation in adult phenotype, suggesting that the remaining phenotypic variation could be controlled by other genes within the interval. Although functional studies on are now needed to determine its exact developmental role, our results are in accordance with the classical supergene hypothesis, whereby several genes inherited together due to tight linkage control a major developmental switch.
揭示多态性状的遗传基础是我们理解生物起源和多样性的核心。最近，超级基因已被证明与广泛的复杂多态性有关，从蝴蝶和鱼类的适应性着色到鸟类和植物的繁殖策略。超级基因的概念现在是生物学中的一个热门话题，需要鉴定其功能元件以阐明高度分化的适应性状的进化。在这里，我们应用不同的基因表达分析来研究控制新热带蝴蝶拟态翅色图案多态性的超级基因。
我们使用高通量Illumina RNA测序对不同形态的发育翅盘进行了从头转录组组装和差异表达分析。在该区间内，191个转录本中的30个和17个分别在预蛹和第1天蛹中差异表达。其中包括已知在[具体物种1]和其他鳞翅目昆虫翅图案形成中起作用的[基因名称]基因。我们的原位杂交实验证实了[基因名称]表达与成虫翅图案之间的关系。
本研究发现该区间内的大多数基因在翅色图案形成的关键阶段在发育中的翅盘中表达，并检测到与结构变异相关的多个基因的表达模式发生了剧烈变化。[基因名称]的表达模式仅部分概括了成虫表型的变化，这表明其余的表型变异可能由该区间内的其他基因控制。虽然现在需要对[基因名称]进行功能研究以确定其确切的发育作用，但我们的结果符合经典的超级基因假说，即由于紧密连锁而一起遗传的几个基因控制着一个主要的发育开关。
