Figure 9.

Cladogram representing the regionalization of the prosencephalon based on Isl1 (green)/Nkx2.1 (red) expression. The distribution of the two markers used in our study of the lungfish and urodele forebrains are compared with the situation described in other vertebrate groups such as the lamprey (agnathan) and mouse in which the major differences are found. In all groups, the regions analyzed mainly include comparable molecular compartments. Regarding the Nkx2.1 expression, the main evolutionary events and the moment in which they appear are mentioned and indicated in the scheme by arrows. Note that the developmental stages used in the brain schemes are not equivalent. The schematic representations are made based on the data from: (1) Murakami et al. (2001) and Osorio et al. (2005); (2) present results; Herget et al. (2014), Domínguez et al. (2015) and Santos-Durán et al. (2015); and (3) Puelles et al. (2012), indicated in the figure by the numbers.