The Korea Institute of Ocean Science and Technology (KIOST, President Kim Woong-seo) announced that an analysis done by one of its research teams on the genome of Dendrophyllia cribrosa,^* an endangered species of coral found near Dokdo Island, revealed that the genome is 625Mb in size and has 14 pairs of chromosomes and 30,490 genes. KIOST said that these research results can be used as an important indicator for observing ecological change around Dokdo Island.

* Dendrophyllia cribrosa is a species belonging to the family Dendrophylliidae of order Scleractinia. It is a sessile organism that is found only off the southern coast of Korea and some areas off the eastern coast.

Dendrophyllia cribrosa is a Class II endangered species.^* Its largest coral community, measuring five meters wide and three meters high, was discovered in Dokdo in 2016. Unlike corals in tropical seas, it is a nonsymbiotic coral^* that does not live together with microalgae and is considered to have evolved in a different direction from symbiotic corals.^* However, concrete research results on this have not yet been presented.

* In accordance with the Wildlife Protection and Management Act, endangered wildlife threatened with extinction are classified as Class I endangered wildlife, and endangered wildlife threatened with imminent extinction are classified as Class II endangered wildlife.

* Nonsymbiotic coral: coral that does not live in symbiosis with unicellular microalgae

* Symbiotic coral: coral that lives together with unicellular microalgae in the genus Symbiodinium, on which it relies for a supply of various types of biological energy

To investigate this matter, in 2020, a research team led by senior researcher Yum Seungshic, of the Risk Assessment Research Center of KIOST’s South Sea Research Institute, and the research team of Dr. Kim Jungeun of the Genome Research Foundation (GRF, President Park Jong-hwa) collected, decoded, and analyzed the genome of Dendrophyllia cribrosa located at Ddongyeo, Dokdo, Ulleung-gun, Gyeongsangbuk-do, obtained a high-quality chromosome-level reference genome, and released the research results in a journal article.^*

* KIOST Yum Seungshic, GRF Kim Jungeun, et al., Genome Biology and Evolution, September 2022 (title: Comparative genome and evolution analyses of an endangered stony coral species Dendrophyllia cribrosa near Dokdo Islands in the East Sea)

The research results revealed that Dendrophyllia cribrosa, which lacks symbionts, evolved to acquire cellular energy through the expansion of genes related to Acyl-CoA metabolism^* and carbohydrate transporters.^* This species also has immune-related genes that are likely to be involved in how it protects itself from the infiltration of external microorganisms.

* Acyl-CoA metabolism: the process of activating fatty acid, which is essential in the supply of energy

* Carbohydrate transporters: molecules that promote the movement of carbohydrates, an important source of energy, across cell walls as well as between cells.

KIOST President Kim Woong-seo said, “These research results are expected to help prevent the pending global marine ecosystem crisis by establishing a new paradigm for the preservation of coral communities at risk of extinction. It is hoped that the results will contribute to ensuring Korea’s territorial sovereignty as well as sovereignty over the nation’s marine biological resources.”

This research was conducted under the “Study on the sustainable use of Dokdo” (senior researcher: Park Chan-hong) and as part of the National Agricultural Genome Program (NAGP). Going forward, KIOST plans to accelerate research on the unique metabolism and physiological characteristics of nonsymbiotic corals.