Table_3_The Significance of Genotypic Diversity in Coral Competitive Interaction: A Transcriptomic Perspective.DOCX

Competitive interactions shape coral assemblages and govern the dynamics of coral ecosystems. Although competition is an ecological concept, the outcomes of competitive interactions are ultimately determined by patterns of gene expression. These patterns are subject to genotypic variation on both sides of any interaction. Such variation is typically treated as “noise”, but it is sometimes possible to identify patterns within it that reveal important hidden factors in an experiment. To incorporate genotypic variation into the investigation of coral competitive interactions, we used RNA-sequencing to study changes in gene expression in a hard coral (Porites cylindrica) resulting from non-contact competition experiment with a soft coral (Lobophytum pauciflorum). Hard coral genotype explained the largest proportion of variation between samples; however, it was also possible to detect gene expression changes in 76 transcripts resulting from interaction with the soft coral. In addition, we found a group of 20 short secreted proteins that were expressed as a coordinated unit in three interacting Porites-Lobophytum pairs. The presence of this secretion response was idiosyncratic in that it could not be predicted based on polyp behaviour, or the genotype of hard or soft coral alone. This study illustrates the significance of individual variation as a determinant of competitive behaviour, and also provides some intriguing glimpses into the molecular mechanisms employed by hard corals competing at a distance.

竞争性互动塑造珊瑚群落，并支配珊瑚生态系统的动态变化。尽管竞争是一个生态学概念，但竞争性互动的结果最终由基因表达的模式所决定。这些模式受到任何互动双方基因型的变异影响。此类变异通常被视为“噪声”，但有时可以在其中识别出模式，从而揭示实验中重要的隐藏因素。为了将基因型变异纳入珊瑚竞争性互动的研究之中，我们采用RNA测序技术，研究硬珊瑚（Porites cylindrica）在与软珊瑚（Lobophytum pauciflorum）的非接触性竞争实验中基因表达的变化。硬珊瑚基因型解释了样本间最大的变异比例；然而，也有可能检测到76个转录本中的基因表达变化，这些变化是由与软珊瑚的互动引起的。此外，我们发现一组20种短分泌蛋白，在三个Porites-Lobophytum互动对中作为协调单元表达。这种分泌反应的存在具有独特性，因为它不能仅基于珊瑚群体行为，或硬珊瑚或软珊瑚的基因型来预测。本研究阐述了个体变异作为竞争行为决定因素的重要性，同时也为硬珊瑚在距离竞争中采用的分子机制提供了引人入胜的洞察。