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Vous êtes ici : Accueil / Équipes / Comparative and Integrative Genomics of Organ Development - S.Pantalacci/M. Semon / Thèmes de recherche / Developmental systems: shaped by but also shaping evolution

Developmental systems: shaped by but also shaping evolution

We are interested in the interplay between the nature of developmental systems and evolution. How did evolution shape them? How do they shape evolution in return?

We are interested in the interplay between the nature of developmental systems and evolution. How did evolution shape them? How do they shape evolution in return?

Our favorite model, the molars of present-day rodents are the product of a long evolutionary history, fairly well known thanks to paleontological data. How did this evolutionary history shape the present-day developmental systems producing the first lower and upper molars of mouse, or other related rodents? In turn, how do these developmental systems influence more recent micro or macro-evolution of molars in mouse and relatives?

  • Vestigial buds in development and evolution of rodents molars

Mouse ancestors had premolars, and this is reflected in the developmental system of present-day mouse and mouse-related rodents, with the presence of a transient, vestigial, tooth germ in the developing molar row (Prochazka, Pantalacci et al. 2010). We studied how this vestigial tooth germ influences first molar development, and favored repeated molar elongation in mouse populations. We test our hypothesis by combining mathematical modeling, experimental approaches and comparative transcriptomics in different mouse strains (Sadier et al. Plos Biology 2019; Hayden et al. Elife 2020; see also the accompanying insight by C. Roseman). We pay special attention to the temporal dynamics of the developmental system with a quantitative and probabilistic treatment of series of fixed embryos.

People involved in the team: Luke Hayden (Past member)

Collaborations: Vincent Calvez, CNRS & Institut Camille Jordan, Université Claude Bernard Lyon 1; Sabrina Renaud, LBBE, Université Lyon 1; Maria Hovorackova and Renata Peterkova, Institute of Experimental medecine, Czech Republic

  • Evolving two teeth independently despite gene pleiotropy

How can two serial organs, such as limbs or teeth, evolve independently despite gene pleiotropy? The first upper molar of mouse evolved a new adaptive dental plan about 18MYA with two new lingual cusps, while the lower molar kept the ancestral cusp number. We compared mouse upper and lower molar development to hamster, which kept the ancestral cusp number in both teeth. Our study show that evolution used a combination of mutations, one has specific effects on the development of the new upper molar, and others changed both upper and lower molar development, yet were unsufficient in the latest to drastically change its final form (Developmental System Drift).  See the preprint here.

We are now using in silico evolution of tooth morphogenesis to explore the link between gene pleiotropy and DSD.

People involved in the team: Pascal Hagolani

Collaborations: Laurent Guéguen, Phlippe Weber, Université Lyon 1

  • Bucco-lingual development and evolution of rodent molars

Molars originated in early mammals, when already complex teeth evolved cusp arranged in a bucco-lingual direction, with buccal and lingual cusps. More recently, several rodent groups (mice and relatives, spiny mice and relatives, other independent fossil lineages) went a step further, adding a third cusp row on the lingual side of their upper molar. We are interested in understanding how bucco-lingual development originated in mammals and occurs nowadays in mouse and why and how the upper molar repeatedly evolves a third row of cusps (see also here). To this end, we combine 3D imaging, comparative transcriptomics and developmental genetics.

People involved in the team: Coraline Petit (Past member)

Collaborations: Ronan Ledevin, Université Lyon 1;  Maria Hovorackova and Renata Peterkova, Institute of Experimental medecine, Czech Republic