title: Analysis of the FGF gene family provides insights into aquatic adaptation in cetaceans.
abstract: 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.
authors.affiliation: INRA, UMR 1333 Diversité, Génomes &Interactions Microorganismes-Insectes, 2 place E. Bataillon, 34095 Montpellier, France.|Université Montpellier, 2 place E. Bataillon, 34095 Montpellier, France.
authors.forename: Kiwoong
authors.initials: K
authors.lastname: Nam
authors.affiliation: Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Haeanro 787, Ansan 15627, Republic of Korea.
authors.forename: Kyeong Won
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Personal Genomics Institute, Genome Research Foundation, Osong 28160, Republic of Korea.
authors.forename: Oksung
authors.initials: O
authors.lastname: Chung
authors.affiliation: Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Haeanro 787, Ansan 15627, Republic of Korea.|Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon 306-350, Republic of Korea.
authors.forename: Hyung-Soon
authors.initials: HS
authors.lastname: Yim
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 03760, Republic of Korea.
authors.forename: Sun-Shin
authors.initials: SS
authors.lastname: Cha
authors.affiliation: Biomedical Research Institute and IRICT, Seoul National University Hospital, Seoul 110-744, Republic of Korea.
authors.forename: Sae-Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Personal Genomics Institute, Genome Research Foundation, Osong 28160, Republic of Korea.
authors.forename: JeHoon
authors.initials: J
authors.lastname: Jun
authors.affiliation: Personal Genomics Institute, Genome Research Foundation, Osong 28160, Republic of Korea.|The Genomics Institute, Biomedical Engineering Department, UNIST, Ulsan 44919, Republic of Korea.
authors.forename: Yun Sung
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Personal Genomics Institute, Genome Research Foundation, Osong 28160, Republic of Korea.|The Genomics Institute, Biomedical Engineering Department, UNIST, Ulsan 44919, Republic of Korea.|Geromics, Ulsan 44919, Republic of Korea.
authors.forename: Jong
authors.initials: J
authors.lastname: Bhak
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom.
authors.forename: João Pedro de
authors.initials: JP
authors.lastname: Magalhães
authors.affiliation: Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Haeanro 787, Ansan 15627, Republic of Korea.|Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon 306-350, Republic of Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Haeanro 787, Ansan 15627, Republic of Korea.|Department of Marine Biotechnology, Korea University of Science and Technology, Daejeon 306-350, Republic of Korea.
authors.forename: Jae-Yeon
authors.initials: JY
authors.lastname: Jeong
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D019143:Evolution, Molecular; D005346:Fibroblast Growth Factors / Q000235:genetics*; D050617:Fin Whale / Q000235:genetics* / Q000502:physiology*; D016678:Genome; D010802:Phylogeny; D012641:Selection, Genetic
chemical_list: D005346:Fibroblast Growth Factors