Patterns of correlation and covariation of anthropoid distal forelimb segments correspond to Hoxd expression territories
Article first published online: 13 DEC 2007
Copyright © 2007 Wiley-Liss, Inc., A Wiley Company
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Volume 310B, Issue 3, pages 240–258, 15 May 2008
How to Cite
Reno, P. L., McCollum, M. A., Cohn, M. J., Meindl, R. S., Hamrick, M. and Lovejoy, C. O. (2008), Patterns of correlation and covariation of anthropoid distal forelimb segments correspond to Hoxd expression territories. J. Exp. Zool., 310B: 240–258. doi: 10.1002/jez.b.21207
- Issue published online: 4 APR 2008
- Article first published online: 13 DEC 2007
- Manuscript Accepted: 23 OCT 2007
- Manuscript Revised: 14 OCT 2007
- Manuscript Received: 6 AUG 2007
- National Science Foundation. Grant Numbers: SBR-9729060, 0311768.
Anthropoids in general and hominoids in particular exhibit differential adaptations in forearm and digital skeletal proportions to a diverse array of locomotor modes. Hox genes act as selector genes with spatially regulated expression patterns during development. Their expression in the forelimb appears to define modules that specify differential skeletal growth. Here we explore forelimb skeletal proportions in a large sample of anthropoids from a background provided by Hoxd expression patterns in late-stage murine embryonic forelimbs. Interspecific correlation and principal components analyses of primate forelimb data indicate that morphological variation in anthropoids reflects well-defined developmental modules downstream of Hoxd expression. The phalanges of digit one appear to represent a single growth module, whereas the metacarpals and manual phalanges of the posterior digits correspond to a second, independent, expression territory that extends proximally into the distal zeugopod. In particular, hominoids show very high correlations among the posterior digits and the independence of digit one. In addition, the distal radius is generally highly correlated with the posterior digits and not digit one. Relying on established functional differences among Hox paralogs, we present a model that parsimoniously explains hominoid forearm and digital proportions as a consequence of downstream effects of Hox. We, therefore, suggest that Hox-defined developmental modules have served as evolutionary modules during manual evolution in anthropoids. J. Exp. Zool. (Mol. Dev. Evol.) 310B:240–258, 2008. © 2007 Wiley-Liss, Inc.