VertEvo Logo 02 (100dpi) News


News archive

Read here about past events.

Cover story!
Evolution & Development

New insights into the  Hox code

Evo&Devo CoverVariation in axial formulae (i.e. number and identity of vertebrae) is an important feature in the evolution of vertebrates. Vertebrae at different axial positions exhibit a region-specific morphology. Key determinants for the establishment of particular vertebral shapes are the highly conserved Hox genes.

Here, we analysed Hox gene expression in the presacral vertebral column in the Nile crocodile in order to complement and extend a previous examination in the alligator and thus establish a Hox code for the axial skeleton of crocodilians in general. The newly determined expression of HoxA-4, C-5, B-7, and B-8 all revealed a crocodilian-specific pattern. HoxA-4 and HoxC-5 characterise cervical morphologies and the latter furthermore is associated with the position of the forelimb relative to the axial skeleton. HoxB-7 and HoxB-8 map exclusively to the dorsal vertebral region. The resulting expression patterns of these two Hox genes is the first description of their exact expression in the archosaurian embryo.

Our comparative analyses of the Hox code in several amniote taxa provide new evidence that evolutionary differences in the axial skeleton correspond to changes in Hox gene expression domains. We detect two general processes: 1) expansion of a Hox gene’s expression domain as well as 2) a shift of gene expression. We infer that the ancestral archosaur Hox code may have resembled that of the crocodile. In association with the evolution of morphological traits, it may have been modified to patterns that can be observed in birds.

Böhmer C, Rauhut OWM, Wörheide G. 2015 New insights into the vertebral Hox code of archosaurs. Evolution & Development 17; 5, 258-269 (2015). DOI: 10.111/ede.12136.

Press release:
Ludwig-Maximilians-Universität in Munich (for english version [here]).

Please feel free to [contact me] for details.

Böhmer et al Evo&Devo (400 px)
isadf2014 Logo-frei

Oral presentation by Christine

International Symposium on Asian Dinosaurs 2014

The International Symposium on Asian Dinosaurs, Fukui (ISADF) was organized by Fukui Prefectural Dinosaur Museum, Asia Dinosaur Association, and the  Dinosaur Research Institute, Fukui Prefectural University in  commemoration of the establishment of Asia Dinosaur Association.

Report of the ISADF2014.

The symposium focuses on dinosaurs and other Mesozoic biota in Asia. Through research presentations, it aims to provide opportunities of  discussions and interactions for those who are interested in dinosaurs  and related paleoenvironments and paleoecology.

Next meeting:
Bangkok (Thailand), November 19-24 2015

Invited talk: Birmingham (UK)

From genes to vertebrae: molecular backbone of dinosaur necks

Dr. Richard Butler invited me to visit his research group at the University of Birmingham. I gave a talk about my research on the molecular backbone of dinosaur necks.

(C) Böhmer 2015
Böhmer et al (in press) Abbildung verk

Open Access! Proceedings B

The dinosaur Hox code

The relationship between developmental genes and phenotypic variation is of central interest in evolutionary biology. An excellent example is the role of Hox genes in the anteroposterior regionalization of the vertebral column in vertebrates. Archosaurs (crocodiles, dinosaurs including birds) are highly variable both in vertebral morphology and number. Nevertheless, functionally equivalent Hox genes are active in the axial skeleton during embryonic development, indicating that the morphological variation across taxa is likely due to modifications in the pattern of Hox gene expression.

By using geometric morphometrics, we demonstrate a correlation between vertebral Hox code and quantifiable vertebral morphology in modern archosaurs, in which the boundaries between morphological subgroups of vertebrae can be linked to anterior Hox gene expression boundaries. Our findings reveal homologous units of cervical vertebrae in modern archosaurs, each with their specific Hox gene pattern, enabling us to trace these homologies in the extinct sauropodomorph dinosaurs, a group with highly variable vertebral counts.

Based on the quantifiable vertebral morphology, this allows us to infer the underlying genetic mechanisms in vertebral evolution in fossils, which represents not only an important case study, but will lead to a better understanding of the origin of morphological disparity in recent archosaur vertebral columns.

Press release:
Ludwig-Maximilians-Universität in Munich (for english version [here]).

SNSB-Bayerische Staatssammlung für Paläontologie und Geologie in Munich

Böhmer C, Rauhut OWM, Wörheide G. 2015 Correlation between Hox code and vertebral morphology in archosaurs. Proc. R. Soc. B  282: 20150077. DOI: 10.1098/rspb.2015.0077.


© Copyright 2012-2017 C. Böhmer. Designed by C. Böhmer. All rights reserved. Impressum