The First Draft Genome of a Cold-Water Coral Trachythela sp. (Alcyonacea: Stolonifera: Clavulariidae)

Cold-water corals (CWCs) are important habitats for creatures in the deep-sea environment, but they have been degraded by anthropogenic activity. So far, no genome for any CWC has been reported. Here, we report a draft genome of Trachythela sp., which represents the first genome of CWCs to date. In total, 56 and 65 Gb of raw reads were generated from Illumina and Nanopore sequencing platforms, respectively. The final assembled genome was 578.26 Mb, which consisted of 396 contigs with a contig N50 of 3.56 Mb, and the genome captured 90.1% of the metazoan Benchmarking Universal Single-Copy Orthologs. We identified 335 Mb (57.88% of the genome) of repetitive elements, which is a higher proportion compared with others in the Cnidarians, along with 35,305 protein-coding genes. We also detected 483 expanded and 51 contracted gene families, and many of them were associated with longevity, ion transposase, heme-binding nicotinamide adenine dinucleotide, and metabolic regulators of transcription. Overall, we believe this genome will serve as an important resource for studies on community protection for CWCs.