BBS Faculty Member - Arkhat Abzhanov

Arkhat Abzhanov

Department of Organismic and Evolutionary Biology

Harvard University/OEB
FAS Biological Labs 4105
14 Divinity Ave.
Cambridge, MA 02138
Tel: 617-496-9704
Fax: 617-495-9507
Email: abzhanov@fas.harvard.edu
Visit my lab page here.



We are interested in the genetic/molecular mechanisms of the vertebrate craniofacial development and evolution with a particular focus on the cranial skeletal structures.

Research projects in our laboratory range from studies on early craniofacial development and differentiation of the cranial neural crest cells to the later events in cranial skeletogenesis, such as formation of skull dermal bone and integration of cranial skeleton and musculature. The species we work with range from the laboratory “model” systems, such as chicken embryos and mouse mutants, to the “non-model” species used for evolutionary developmental studies such as Darwin’s Finches and their relatives, other birds and reptiles.

Some of the major current projects:

Cranial Neural Crest Differentiation. During development neural crest cells give rise to a wide variety of specialized cell types in response to signals from the surrounding tissues. Our previous work elucidated some of these signals and currently we are working on differentiation of cranial neural crest cells into skeletal cell types (osteoblasts, chondrocytes and odontoblasts) both in vitro and in vivo using cell biology and bioinformatics approaches. We would also like to understand how these differentiation processes differ from those in mesodermally-derived progenitors.

Intramembranous Bone Development. The bones of the trunk (limbs, vertebrae, etc) are mesodermally-derived and form by endochondral ossification, i.e. via formation of cartilage templates later replaced by bone. In contrast, many cranial bones, including skull cranial vault, jaws and face, form from cranial neural crest and are classified as intramembranous (dermal) bones that form directly through ossification of condensations in the cranial dermis, a process which is very poorly understood. Our goal is to analyze formation of cranial intramembranous (dermal) bone on both cellular and tissue levels.

Craniofacial evolutionary-developmental biology (Evo-Devo). The faces of vertebrates are often readily recognizable as they display a number of species-specific characteristics. It is likely that this stunning diversity of cranial morphology in vertebrates was generated by alterations in craniofacial development. We are employing a combination of genetic, genomic, molecular, bioinformatics, 2-D and 3-D imaging and modeling approaches to understand evolution of craniofacial structures, such as highly adaptive beak morphology in such species as Darwin’s Finches (a classic example of species multiplication and diversification caused by natural selection); African Seedcrackers (textbook example of adaptive polymorphism), cranial morphology in anole lizards (famous example of convergent/parallel evolution) and other avian and reptilian species.



Last Update: 8/28/2013



Publications

For a complete listing of publications click here.

 


 

Mallarino, R., O. Campas, J. Fritz, K. J. Burns, M. P. Brenner, and A. Abzhanov (2012) “Different regulatory mechanisms underlie the evolution of beak shapes convergence in closely related species of birds”. Proc. Natl. Acad. Sci. (in press)

Mallarino, R.M. and Abzhanov, A. (2012) Paths Less Travelled: Evo-Devo Approaches to Investigating Animal Morphological Evolution. Annual Review of Cell and Developmental Biology (in press).

Bhullar, B., J. Marugán-Lobón, F. Racimo, G.S. Bever, M.A. Norell, T. B. Rowe and Abzhanov, A. (2012) Birds have paedomorphic dinosaur skulls. Nature 487, 223–226.

T.J. Sanger, D. L. Mahler, A. Abzhanov and J. B. Losos (2012). Roles for Modularity and Constraint in the Evolution of Cranial Diversity Among Anolis Lizards. Evolution 66, 1525-1542 (last authors contributed equally).

Mallarino, R.M., A. Herrel, W. P. Kuo, B. R. Grant, P. R. Grant, and A. Abzhanov (2011) Two developmental modules establish 3D beak-shape variation in Darwin’s finches. Proc. Natl. Acad. Sci. 108, 4057-4062.



© 2013 by the President and Fellows of Harvard College