Send to

Choose Destination
Int J Dev Biol. 1994 Sep;38(3):549-52.

Conservation in the Hox code during morphological evolution.

Author information

Department of Development and Signalling, Babraham Institute, Cambridge, United Kingdom.


The expression domains in paraxial mesoderm of the chicken embryo are described for Hoxb-3, a-4 and c-6 genes, and these are compared with published expression data for the corresponding genes in the mouse. In both species, it is found that the anterior limits of Hoxb-3 and a-4 expression lie in the upper cervical region, and the anterior limits of Hoxc-6 expression lie in the upper thoracic region. This finding is remarkable because the cervical region, or neck, of the chicken (with fourteen cervical vertebrae) is much longer than that of the mouse (seven cervical vertebrae). The results suggest that the Hox code, at least in the development of homologous axial structures, is conserved between species (Hoxb-3 and a-4, for example, being associated with an anterior cervical phenotype; Hoxc-6 being associated with an anterior thoracic phenotype). The results also suggest that an evolutionary change in body proportions is accomplished by a shift in the relative positions of Hox expression domains during embryonic development.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for The International Journal of Developmental Biology
Loading ...
Support Center