Despard Brecia A, Selwyn Jason D, Shupp Allison N, Vollmer Steven V
Department of Marine and Environmental Sciences Northeastern University Nahant Massachusetts USA.
Genomics CORE Laboratory Texas A&M University-Corpus Christi Corpus Christi Texas USA.
Ecol Evol. 2025 Apr 25;15(4):e71351. doi: 10.1002/ece3.71351. eCollection 2025 Apr.
Coral reefs are increasingly threatened by disease outbreaks, yet little is known about the genetic mechanisms underlying disease resistance. Since the 1970s, White Band Disease (WBD) has decimated the Caribbean staghorn coral . However, 15% or more of individuals are highly disease-resistant, and the genes controlling the production of Argonaut proteins, involved in microRNA (miRNA) post-transcriptional gene silencing, are up-regulated in WBD-resistant corals. This suggests that miRNAs may be key regulators of coral immunity. In this study, we conducted an in situ disease transmission experiment with five healthy-exposed control tanks and five WBD-exposed tanks, each containing 50 genotypes, sampled over 7 days and then sequenced miRNAs from 12 replicate genotypes, including 12 WBD-exposed and 12 healthy-exposed control fragments from two time points. We identified 67 miRNAs in , 3 of which are differentially expressed in disease-resistant corals. We performed a phylogenetic comparison of miRNAs across cnidarians and found greater conservation of miRNAs in more closely related taxa, including all three differentially expressed miRNAs being conserved in more than one coral. One of the three miRNAs has putative genomic targets involved in the cnidarian innate immunity. In addition, community detection coupled with over-representation analysis of our miRNA-messenger RNA (mRNA) target network found two key unique miRNAs regulating multiple important immune-related pathways such as Toll-like receptor pathway, endocytosis, and apoptosis. These findings highlight how multiple miRNAs may help the coral host maintain immune homeostasis in the presence of environmental stress including disease.
珊瑚礁正日益受到疾病爆发的威胁，但对于抗病性背后的遗传机制却知之甚少。自20世纪70年代以来，白带病（WBD）已使加勒比鹿角珊瑚大量死亡。然而，15%或更多的个体具有高度抗病性，并且在抗病的珊瑚中，参与微小RNA（miRNA）转录后基因沉默的、控制精氨酸蛋白产生的基因被上调。这表明miRNA可能是珊瑚免疫的关键调节因子。在本研究中，我们进行了一项原位疾病传播实验，设置了五个健康暴露对照水箱和五个WBD暴露水箱，每个水箱包含50个基因型，在7天内进行采样，然后对来自12个重复基因型的miRNA进行测序，包括来自两个时间点的12个WBD暴露片段和12个健康暴露对照片段。我们在其中鉴定出67种miRNA，其中3种在抗病珊瑚中差异表达。我们对刺胞动物的miRNA进行了系统发育比较，发现亲缘关系更近的分类群中miRNA的保守性更高，包括所有三种差异表达的miRNA在不止一种珊瑚中保守。这三种miRNA中的一种具有参与刺胞动物固有免疫的假定基因组靶点。此外，通过对我们的miRNA-信使RNA（mRNA）靶标网络进行群落检测和过表达分析，发现了两种关键的独特miRNA，它们调节多种重要的免疫相关途径，如Toll样受体途径、内吞作用和细胞凋亡。这些发现突出了多种miRNA如何在包括疾病在内的环境压力下帮助珊瑚宿主维持免疫稳态。
