The cerebral hemispheres are the most expanded brain region in most vertebrate lineages, and these expansions are generally associated with increases in behavioral complexity. In association with these expansions, the dorsal component of the hemispheres (the pallium) develops diverging morphologies in the various vertebrate classes, making it very difficult to establish correspondences between groups. Novel RNA sequence technologies and analytic capacities enable us to investigate regional identities through unbiased comparisons across species using the whole transcriptome [Belgard et al., 2013; Belgard and Montiel, 2013; Pfenning et al., 2014; Montiel et al., 2016].
