Gene Loss

Publication Details

Identifier: JB_Z5GI2Q

Curator: Gonçalo Themudo

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.

Last update:

16-01-2025

Associated Glosses (9 results)

GlossID	Species	Symbol	Gene Loss Mechanism	Loss Type	Lineage Specific	Citation
GL_BFAHF4	Balaena mysticetus	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_ND0VW1	Orcinus orca	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_O0RVTU	Balaenoptera acutorostrata	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_OZKWYM	Loxodonta africana	FGF22	Exon(s) deletion	Full	No	10.1038/srep40233
GL_PZB0AJ	Tursiops truncatus	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_STGBER	Balaenoptera physalus	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_U5NY8V	Physeter catodon	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_U9JRFI	Neophocaena phocaenoides	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233
GL_UNQBRO	Lipotes vexillifer	FGF22	LOF (frameshift, premature stop, ss)	Full	No	10.1038/srep40233