Mutualisme .

With Guillemette Duchateau-Nguyen

A population dynamics approach based on a system of differential equations allows us to establish conditions for the emergence of mutualism for cases such as coelenterates-algae symbionts. In hydrae/algae associations, algae are first ingested in the apex of digestive cells and then migrate to their basis. A central assumption of the model is that a host organism is able to discriminate, via some molecular recognition mechanisms, among different invading organisms and preferentially reject commensalists rather than bona fide symbionts.

Our model allows us to show that emergence of mutualism is made possible by selective ingestion (association). Migration selectivity does not allow the establishment of mutualism but increases its stability once it is established. Different attractors of the population dynamics correspond to the emergence of mutualism, predominance of "selfish" species, or coexistence of many species.

References

[1] Weisbuch, G. and G. Duchateau. (1993) Emergence of mutualism. Bull. of Math. Biology, 55, 6, 1063-1090.

[2] G. Duchateau-Nguyen, Weisbuch, G. and L. Peliti (1994) A compartimental model of mutualism. Journal of biological systems