Analysis of the FGF gene family provides insights into aquatic adaptation in cetaceans

• Published in: Scientific Reports
• Main Authors: Nam, Ki Woong, Lee, Kyeong Won, Chung, Oksung, Yim, Hyung-Soon, Cha, Sun-Shin, Lee, Sae-Won, Jun, Jehoon, Cho, Yun Sung, Bhak, Jong, de Magalhaes, Joao Pedro, Lee, Jung-Hyun, Jeong, Jae-Yeon
• Other Authors: Diversité, Génomes & Interactions Microorganismes - Insectes Montpellier (DGIMI), Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM), Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology (KIOST), Personal Genomics Institute, Genome Research Foundation, Department of Marine Biotechnology, Korea University of Science and Technology, Department of Chemistry and Nano Science, EWHA Womans University (EWHA), Biomedical Research Institute and IRICT, Seoul National University Hospital, Biomedical Engineering Department, King‘s College London, Institute of Integrative Biology, Korea Institute of Ocean Science & Technology (KIOST) PE99413); National Research Foundation of Korea NRF-2015R1A2A2A01004168, Reference genomes building and application for large scale population genomics' Research Fund of Ulsan National Institute of Science & Technology (UINST) 1.160003.01
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: cetacean; whale; cetace; densité osseuse; baleine; milieu aquatique; séquençage du génome; physiologie animale; pseudogénisation; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Baleine; Fin whale
• Online Access: https://hal.archives-ouvertes.fr/hal-01605138; https://hal.archives-ouvertes.fr/hal-01605138/document; https://hal.archives-ouvertes.fr/hal-01605138/file/2017_Nam_Scientific%20Reports_1.pdf; https://doi.org/10.1038/srep40233

Cetacean body structure and physiology exhibit dramatic adaptations to their aquatic environment. Fibroblast growth factors (FGFs) are a family of essential factors that regulate animal development and physiology; however, their role in cetacean evolution is not clearly understood. Here, we sequenced the fin whale genome and analysed FGFs from 8 cetaceans. FGF22, a hair follicle-enriched gene, exhibited pseudogenization, indicating that the function of this gene is no longer necessary in cetaceans that have lost most of their body hair. An evolutionary analysis revealed signatures of positive selection for FGF3 and FGF11, genes related to ear and tooth development and hypoxia, respectively. We found a D203G substitution in cetacean FGF9, which was predicted to affect FGF9 homodimerization, suggesting that this gene plays a role in the acquisition of rigid flippers for efficient manoeuvring. Cetaceans utilize low bone density as a buoyancy control mechanism, but the underlying genes are not known. We found that the expression of FGF23, a gene associated with reduced bone density, is greatly increased in the cetacean liver under hypoxic conditions, thus implicating FGF23 in low bone density in cetaceans. Altogether, our results provide novel insights into the roles of FGFs in cetacean adaptation to the aquatic environment.