Journal of Molecular Evolution

, Volume 45, Issue 1, pp 43–49

Genomic organization of the extracellular coding region of the human FGFR4 and FLT4 genes: Evolution of the genes encoding receptor tyrosine kinases with immunoglobulin-like domains

  • François Agnès
  • Marguerite-Marie Toux
  • Catherine André
  • Francis Galibert

DOI: 10.1007/PL00006199

Cite this article as:
Agnès, F., Toux, MM., André, C. et al. J Mol Evol (1997) 45: 43. doi:10.1007/PL00006199


Receptor tyrosine kinases with five, seven, and three Ig-like domains in their extracellular region are grouped in subclasses IIIa, IIIb, and IIIc, respectively. Here, we describe the genomic organization of the extracellular coding region of the human FGFR4 (IIIc) and FLT4 (IIIb) genes and compare it to that of the human FGFR1(IIIc), KIT, and FMS (IIIa). The results show that while genes belonging to the same subclass have an identical exon/intron structure in their extracellular coding region-as they do in their intracellular coding regiongenes of related subclasses only have a similar exon/ intron structure. These results strongly support the hypothesis that the genes of the three subclasses evolved from a common ancestor by duplications involving entire genes, already in pieces. Hypotheses on the origin of introns and on the difference in the number of extracellular Ig-like domains in the three gene subclasses are discussed.

Key words

Receptor tyrosine kinaseExtracellular immunoglobulin-like domainsDuplicationsIntron insertion



fibroblast growth factor receptor


Fms-like tyrosine




downstream part


upstream part

Copyright information

© Springer-Verlag New York Inc 1997

Authors and Affiliations

  • François Agnès
    • 1
  • Marguerite-Marie Toux
    • 1
  • Catherine André
    • 1
  • Francis Galibert
    • 2
  1. 1.Laboratoire de Biochimie et Biologie Molé culaireUPR41 CNRS, Faculté de Mé decineRennes CedexFrance
  2. 2.Centre de Bìologìe du DeveloppementToulouse CedexFrance