Expression pattern and role of Galectin1 during early mouse myogenesis.

Galectin1, the prototype member of a family of carbohydrate binding proteins, is involved in muscle stem cell behavior and in tissue regeneration after muscle injury in adult mice. Here, we addressed the question of when this gene is first acting in the muscle lineage. We found that Galectin1 is an early marker of myogenesis as the transcripts and protein are initially confined to the somites, starting from day 9.0 of embryogenesis. We next investigated its relationship with the muscle determination factors, Myf5 and Myod. By comparing the spatio-temporal distribution of Galectin1 transcripts in control and Myf5 null mutant embryos, we were able to establish that it acts downstream of Myf5. However, early myogenesis does not seem affected in Galectin1 null mutant embryos indicating that, unlike in the adult, Galectin1 does not play a role in muscle fate acquisition during development.