The evolution of the vertebrate cerebellum: absence of a proliferative external granule layer in a non-teleost ray-finned fish.

ABSTRACT: The cerebellum represents one of the most morphologically variable structures in the vertebrate brain. To shed light on its evolutionary history, we have examined the molecular anatomy and proliferation of the developing cerebellum of the North American paddlefish, Polyodon spathula. Absence of an external proliferative cerebellar layer and the restriction of Atonal1 expression to the rhombic lip and valvular primordium demonstrate that transit amplification in a cerebellar external germinal layer, a prominent feature of amniote cerebellum development, is absent in paddlefish. Furthermore, expression of Sonic hedgehog, which drives secondary proliferation in the mouse cerebellum, is absent from the paddlefish cerebellum. These data are consistent with what has been observed in zebrafish an

SUBMITTER: Butts T 

PROVIDER: S-EPMC5042320 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature