Development Genes and Evolution

, Volume 214, Issue 8, pp 418–421

Homology and homocracy revisited: gene expression patterns and hypotheses of homology

Opinion Article


Homocracy, a term referring to shared regulatory gene expression patterns between organs in different animals, was introduced recently in order to prevent inappropriate inference of organ homology based on gene expression data. Non-homologous structures expressing homologous genes, and homologous structures expressing non-homologous genes illustrate that gene expression data is not sufficient on its own to identify morphological homology. However, gene expression data might be useful in testing hypotheses of organ homology, because parsimony can be applied on changes in the relation between expression of orthologous regulatory genes and the formation of homologous organs. A method of testing organ homology hypotheses with respect to change in regulatory gene expression required within a particular phylogenetic context is presented.


Homology Homocracy Phylogeny Expression data Synapomorphy 


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Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.Institut für Spezielle Zoologie und Evolutionsbiologie mit Phyletischem MuseumJenaGermany

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