BACKGROUND Heliopora coerulea, the blue coral, is the octocoral characterized by its blue skeleton. Recently, two Heliopora species were delimited by DNA markers: HC-A and HC-B. To clarify the genomic divergence of these Heliopora species (HC-A and HC-B) from sympatric and allopatric populations in Okinawa, Japan, we used a high throughput reduced representation genomic DNA sequencing approach (ezRAD). RESULTS We found 6742 biallelic SNPs shared among all target populations, which successfully distinguished the HC-A and HC-B species in both the sympatric and allopatric populations, with no evidence of hybridization between the two. In addition, we detected 410 fixed SNPs linking functional gene differences, including heat resilience and reproductive timing, between HC-A and HC-B. CONCLUSIONS We confirmed clear genomic divergence between Heliopora species and found possible genes related to stress-responses and reproduction, which may shed light on the speciation process and ecological divergence of coral species.

中文翻译：

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RADseq的人口基因组学证实了蓝珊瑚（Heliopora coerulea）密切相关物种之间的差异。

背景技术蓝色珊瑚Heliopora coerulea是八角珊瑚，其特征是蓝色骨骼。最近，两种Heliopora物种被DNA标记划界：HC-A和HC-B。为了阐明这些冲孔虫物种（HC-A和HC-B）在日本冲绳同胞和异特异种群中的基因组差异，我们使用了高通量简化代表性基因组DNA测序方法（ezRAD）。结果我们在所有目标人群中发现了6742个双等位基因SNP，成功区分了同胞和异源人群中的HC-A和HC-B物种，而没有证据表明两者之间存在杂交。此外，我们检测到410个固定的SNP，它们连接HC-A和HC-B之间的功能基因差异，包括耐热性和生殖时间。