The Korea Institute of Ocean Science and Technology (KIOST, President Hong Gi-hoon) recently announced that one of its research teams has become the first in the world to identify the genes that enabled whales to adapt to ocean life.

Originally, whales were ungulates* that lived on land. However, millions of years ago, they experienced a habitat transition to the ocean. Throughout this evolutionary transition, whales underwent various physiological and biological changes, including a rapid change in bone density.

Millions of years ago, when whales lived in shallow waters, their high bone density weighed them down, but today’s whales have completely adapted to the deep-water ocean environment, as their bone mineral density has decreased enough to allow them to achieve buoyancy. However, until now, little was known about the gene that controlled bone mineral density.

* Ungulates: hooved mammals

A KIOST research team led by senior researcher Dr. Lee Jung-hyun conducted an evolutionary analysis of genes called “fibroblast growth factors (FGFs)*,” leading them to discover that these genes contributed to whales’ adaptation to the aquatic environment.

** Fibroblast growth factors (FGFs): Mammals, such as humans and whales, have 22 FGF members. FGFs are currently being used to develop cures to diseases, as they play important roles in controlling biological changes, such as blood vessel formation, healing of wounds, embryogenesis, cellular differentiation, signal transmission, and metabolic regulation.

The research team found that the evolution of whales occurred through the induced expression of FGF23 in the liver in response to low oxygen levels (hypoxia) while they are underwater, thereby resulting in reduced bone density. This proves that, in all mammals, including humans, hypoxia can control the expression of the FGF23 gene. This discovery is attracting great interest for its potential to further enhance our understanding of human diseases associated with hypoxia.

Dr. Lee commented, “With the discovery and utilization of genes associated with various characteristics acquired by ocean animals throughout their long evolutionary process in the aquatic environment, we expect to gain the capability to identify the causes of more human diseases and develop cures.”

This research was conducted as part of one of KIOST’s major tasks, “Discovery of New Genetic Functions in Organisms in Oceans and Extreme Environments and Development of Utilization Technologies,” and the paper was published in the January 2017 issue of Scientific Reports, a world-leading authoritative journal in the area of convergence science.

*** Thesis title: Analysis of the FGF gene family provides insights into aquatic adaptation in cetaceans. (Lee Jung-hyun, Jeong Jae-yeon, Lee Kyeong-won, and Yim Hyung-soon)