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Many chameleons have the remarkable ability to exhibit complex and rapid color changes during social interactions. A collaboration between the teams led by professors Michel Milinkovitch and Dirk van der Marel, unveils the mechanisms that regulate this phenomenon.

Reproductive barriers between species can sometimes be overcome in nature, producing hybrids that may be fertile. This process results in demographic interactions between species and, in some cases, is accompanied by genetic introgression. However, human introduction of invasive species increases the occurrence of this phenomenon, potentially threatening native species.

Life in a group entails a major risk: that of being exposed to contagious pathogens. To counter this danger, different strategies have evolved in social species. In the case of rodents, specific olfactory signals emitted by sick individuals induce avoidance behavior among their peers.

During the development of mammals, the growth and organization of digits are orchestrated by Hox genes, which are activated very early in precise regions of the embryo. These “architect genes” are themselves regulated by a large piece of adjacent DNA. A study led by Denis Duboule, professor at the University of Geneva (UNIGE) and the Federal Institute of Technology in Lausanne (EPFL), Switzerland, reveals that this same DNA regulatory sequence also controls the architect genes during the development of the external genitals.

Parkinson’s disease is a common age-related disorder that progressively affects movements. The patients present slowness of movements, stiffness, tremor, loss of balance in early stages that can be manageable by medications. But in advanced stages, patients suffer from the debilitating degree of motor dysfunctions in combination with non-motor symptoms such as cognitive dysfunctions, hallucination and delusion, unable to live alone. Although it has been known that these symptoms mainly arise from the progressive loss of dopaminergic neurons in the midbrain substantia nigra, the underlying mechanism is unknown.

Athanasia Tzika and Michel Milinkovitch have participated to an international study demonstrating that the emergence of mammals from egg-laying reptiles has been facilitated by the capture and recycling of a viral gene.

The group of Michel Milinkovitch has recently published a study showing how hair follicle morphogenesis has been altered during the evolution of the spiny mouse (Acomys dimidiatus), resulting in a shift from ancestral hair follicles to enlarged asymmetrical spines.

Hybridization between different species is common in nature but can be increased in frequency or even originated by human actions, such as species introduction or habitat modification.

L'article publié en 2013 dans le journal “Science” par l'équipe de Michel Milinkovitch a été repris par “Science in the Classroom”, un portail d'éducation regroupant des documents de recherche annotés et du matériel pédagogique destiné aux enseignants et élèves des écoles secondaires et des universités.