SICB Annual Meeting
January 4-8, 2005
Town & Country Hotel San Diego, CA
“Evolution and Development of the Vertebrate Dentition”
Organizers: Moya Smith – Tim Mitsiadis (Dental Institute KCL)
Sponsoring divisions: DEDB, DVM, DDCB, and DSEB (primary)
Getting a grip on food, when did genes for making teeth originate in the vertebrate phylogeny?
How do we survive without teeth and can we recreate the real thing again and put back teeth into the jaws? Recently this has been done in birds by producing teeth in the mouth using selected cells from mice that can make teeth. Now the pursuit is on to recreate teeth from stem cells in the human jaws.
Amongst jawed vertebrates fish recreate teeth all the time and cover their jaws and throat extensively with teeth, so what can we learn from the genes that make teeth in fish? How far back in time did tooth making in the jaws evolve? The genetic mechanisms are well understood in the mouse, through molecular techniques combined with embryo manipulation and transgenic animal production. Transcription factors for regulating tooth development were discovered in these model jaw systems. Recently this basic developmental biology is being used in new studies to develop tissue engineering and stem cell methods to regenerate human teeth. We now have data from fish that show many of the same genes are used in the same way in a dentition where teeth occur even deep in the throat where the gut starts.
So did this all begin more than 350 mya in the Devonian placoderm fish, those with massive jaws who thrived by eating early sharks? It appears that they did from a recent study of these extinct fish, at the base of the jawed lineage. But this is controversial; did teeth evolve many times, or once only with a key set of genes? This and other questions, importantly, which genes regulate continuous renewal of teeth, can be solved from studies on living fish. This ability to make an endless supply of teeth is not present in mammals, including the human dentition. However, patterned sets of teeth regulated by genetic pathways start in cells lining the pharynx and mouth, and these genes were conserved from fish to mammals. This controversial new theory is to be debated at this symposium in San Diego.
The set of ‘tooth making’ genes in mice and humans emerged early in vertebrate evolution. These genes probably created the first sets of teeth deep in the throat, just before the last swallow and were there before jaws evolved.
Schedule
8.00 – The origin of vertebrate dentitions each of their own design
Moya Meredith Smith, CFD, Dental Institute, King’s College London, UK and Gareth Fraser, MRC Centre of Developmental Neurobiology, Dental Institute, King’s College London, UK
08.30 – Evolution and development of the skeleton in the earliest vertebrates
Phil Donoghue, Department of Earth Sciences, University of Bristol, UK and Ivan Sansom, School of Earth Sciences, University of Birmingham, UK
09.00 – Patterning of development in tooth replacement in osteichthyan dentitions
Ann Huysseune, Biology Department, University of Ghent, Belgium
09.30 – Genetics and development of the cichlid dentition
Todd Streelman, School of Biology, The Georgia Institute of Technology, Atlanta, GA, USA
10.00 – COFFEE BREAK
10.30 – Origin of dental occlusion in tetrapods, signals for terrestrial vertebrate evolution
Robert Reisz, Biology Department, University of Toronto at Mississauga, Canada
11.00 – Recovery of teeth in birds
Tim Mitsiadis, CFD, Dental Institute King’s College London, UK
11.30 – Phylogenetic memory of developing mammalian dentition.
Renata. Peterkova*1, Hervé Lesot2 and Miroslav Peterka1. Institute of Experimental Medicine, Academy of Sciences, Prague, Czech Republic1, INSERM U-595, Strasbourg, France2
12.00 – LUNCH
13.00 – Differences and correspondences in segmentation of the dental lamina
Ivan Misek, Academy Sciences CR. Institute of Animal Physiology and Genetics, Czech Republic
13.30 – Developmental regulation of dental pattern in the mouse
Martyn Cobourne, CFD, Dental Institute King’s College London, UK
14.00 – Evolutionary genetics of development: teeth as part of vertebrate structural organisation.
Kenneth W. Weiss, Departments of Anthropology and Biology, Penn State University, USA
14.30 – Mammalian dental diversity: so many shapes, so few genes.
Jukka Jernval, Institute of Biotechnology, University of Helsinki, Finland
15.00 – selected contributed papers.
15.30 – POSTERS