Data from: Comparative genomics of color morphs In the coral Montastraea cavernosa

Montastraea cavernosa is a common coral in the Caribbean basin found in several color morphs. To investigate the causes for brown and orange morphs we undertook a genomics approach on corals collected at the same time and depth in the Bahamas. The coral holobiont includes the host, symbiotic dinoflagellates (Symbiodinium spp.), and a diverse microbiome. While the coral host showed significant genetic differentiation between color morphs both the composition of the Symbiodinium spp. communities and the prokaryotic communities did not. Both targeted and global gene expression differences in the transcriptome of the host show no difference in fluorescent proteins while the metatranscriptome of the microbiome shows that pigments such as phycoerythrin and orange carotenoid protein of cyanobacterial origin are significantly greater in orange morphs, which is also consistent with the significantly greater number of cyanobacteria quantified by 16S rRNA reads and flow cytometry. The microbiome of orange color morphs expressed significantly more nitrogenase (nifH) transcripts consistent with their known ability to fix nitrogen. Both coral and Symbiodinium spp. transcriptomes from orange morphs had significantly increased expression of genes related to immune response and apoptosis, which may potentially be involved in maintaining and regulating the unique symbiont population in orange morphs.穴形星状珊瑚（Montastraea cavernosa）是加勒比海盆地的常见珊瑚物种，存在多种色型。为探究棕色与橙色色型的成因，我们对在巴哈马群岛同期、同深度采集的珊瑚样本开展了基因组学研究。珊瑚全共生体（holobiont）包括宿主、共生双鞭毛虫（Symbiodinium spp.，虫黄藻属）以及多样的微生物组。尽管珊瑚宿主在不同色型间存在显著的遗传分化，但虫黄藻属群落的组成与原核生物群落均未表现出显著差异。对宿主转录组的靶向及全局基因表达差异分析显示，荧光蛋白的表达无显著变化；而微生物组的宏转录组分析表明，蓝细菌起源的藻红蛋白、橙色胡萝卜素蛋白等色素在橙色色型中的表达量显著更高，这与通过16S rRNA测序读段与流式细胞术定量得到的蓝细菌数量显著更多的结果一致。橙色色型的微生物组表达了更多的固氮酶（nifH）转录本，这与其已知的固氮能力相符。橙色色型的珊瑚宿主与虫黄藻属的转录组中，与免疫应答及细胞凋亡相关的基因表达量均显著上调，这可能参与维持和调控橙色色型特有的共生菌群种群。