BACKGROUND The Midas cichlid species complex (Amphilophus spp.) is widely known among evolutionary biologists as a model system for sympatric speciation and adaptive phenotypic divergence within extremely short periods of time (a few hundred generations). The repeated parallel evolution of adaptive phenotypes in this radiation, combined with their near genetic identity, makes them an excellent model for studying phenotypic diversification. While many ecological and evolutionary studies have been performed on Midas cichlids, the molecular basis of specific phenotypes, particularly adaptations, and their underlying coding and cis-regulatory changes have not yet been studied thoroughly. RESULTS For the first time in any New World cichlid, we use Tol2 transposon-mediated transgenesis in the Midas cichlid (Amphilophus citrinellus). By adapting existing microinjection protocols, we established an effective protocol for transgenesis in Midas cichlids. Embryos were injected with a Tol2 plasmid construct that drives enhanced green fluorescent protein (eGFP) expression under the control of the ubiquitin promoter. The transgene was successfully integrated into the germline, driving strong ubiquitous expression of eGFP in the first transgenic Midas cichlid line. Additionally, we show transient expression of two further transgenic constructs, ubiquitin::tdTomato and mitfa::eGFP. Transgenesis in Midas cichlids will facilitate further investigation of the genetic basis of species-specific traits, many of which are adaptations. CONCLUSION Transgenesis is a versatile tool not only for studying regulatory elements such as promoters and enhancers, but also for testing gene function through overexpression of allelic gene variants. As such, it is an important first step in establishing the Midas cichlid as a powerful model for studying adaptive coding and non-coding changes in an ecological and evolutionary context.

中文翻译：

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Tol2转座子介导的麦地那慈鲷（Amphilophus citrinellus）的转基因-旨在了解基因功能和生态系统模型中快速表型多样化的调控进化。

背景技术作为在极短时间内（几百代）内同胞形态形成和适应性表型发散的模型系统，麦达斯慈鲷物种复合体（Amphilophus spp。）在进化生物学家中广为人知。适应性表型在这种辐射中反复平行演化，再加上它们的近遗传特性，使其成为研究表型多样化的极佳模型。尽管对麦达斯丽鱼科植物进行了许多生态和进化研究，但具体表型的分子基础，特别是适应性，以及它们潜在的编码和顺式调控变化，尚未得到深入研究。结果在任何新世界丽鱼科鱼中，我们首次在Midas丽鱼科鱼（Amphilophus citrinellus）中使用Tol2转座子介导的转基因。通过适应现有的显微注射方案，我们建立了一种在麦达斯丽鱼科鱼中进行转基因的有效方案。向胚胎注射Tol2质粒构建体，该构建体在泛素启动子的控制下驱动增强的绿色荧光蛋白（eGFP）表达。转基因已成功整合到种系中，从而在第一个转基因麦达斯丽鱼科植物中驱动了eGFP的广泛表达。此外，我们显示了两个另外的转基因构建体，遍在蛋白:: tdTomato和mitfa :: eGFP的瞬时表达。迈达斯丽鱼科植物的转基因将有助于进一步研究物种特异性状的遗传基础，其中许多是适应性的。结论转基因不仅是研究启动子和增强子等调控元件的多功能工具，还可以通过等位基因变体的过表达来测试基因功能。因此，这是将迈达斯丽鱼科鱼确立为研究生态和进化环境下自适应编码和非编码变化的强大模型的重要第一步。