Research Resource: Comprehensive Expression Atlas of the Fibroblast Growth Factor System in Adult Mouse

TLDR

FGF family members and receptors are well known for their roles in embryogenesis, yet their functions in adult physiology remain largely unexplored. We profiled mRNA expression of all 22 FGFs, seven FGFRs, and three Klotho coreceptors across 39 mouse tissues using real‑time qPCR. The atlas reveals that most FGFs/FGFRs cluster into CNS‑enriched or reproductive/gastro‑enriched groups, endocrine FGFs form a distinct cluster lacking FGFRs, and the Klotho member Lactase‑like is highly expressed in brown adipose and eye and can act as an additional coreceptor for FGF19, providing a valuable resource for future studies.

Abstract

Although members of the fibroblast growth factor (FGF) family and their receptors have well-established roles in embryogenesis, their contributions to adult physiology remain relatively unexplored. Here, we use real-time quantitative PCR to determine the mRNA expression patterns of all 22 FGFs, the seven principal FGF receptors (FGFRs), and the three members of the Klotho family of coreceptors in 39 different mouse tissues. Unsupervised hierarchical cluster analysis of the mRNA expression data reveals that most FGFs and FGFRs fall into two groups the expression of which is enriched in either the central nervous system or reproductive and gastrointestinal tissues. Interestingly, the FGFs that can act as endocrine hormones, including FGF15/19, FGF21, and FGF23, cluster in a third group that does not include any FGFRs, underscoring their roles in signaling between tissues. We further show that the most recently identified Klotho family member, Lactase-like, is highly and selectively expressed in brown adipose tissue and eye and can function as an additional coreceptor for FGF19. This FGF atlas provides an important resource for guiding future studies to elucidate the physiological functions of FGFs in adult animals.