Migratory patterns and evolutionary plasticity of cranial neural crest cells in ray-finned fishes.

Migratory patterns and evolutionary plasticity of cranial neural crest cells in ray-finned fishes.
Dev Biol. 2020 Aug 21;:
Authors: Stundl J, Pospisilova A, Matějková T, Psenicka M, Bronner ME, Cerny R
Abstract
The cranial neural crest (CNC) arises within the developing central nervous system, but then migrates away from the neural tube in three consecutive streams termed mandibular, hyoid and branchial, respectively, according to the order along the anteroposterior axis. While the process of neural crest emigration generally follows a conserved anterior to posterior sequence across vertebrates, we find that ray-finned fishes (bichir, sterlet, gar, and pike) exhibit several heterochronies in the timing and order of CNC emergence that influences their subsequent migratory patterns. First, emigration of the cranial neural crest in these fishes occurs prematurely compared to other vertebrates, already initiating during early neurulation and well before neural tube closure. Second, delamination of the hyoid stream occurs prior to the more anterior mandibular stream; this is associated with early morphogenesis of key hyoid structures like external gills (bichir), a large opercular flap (gar) or first forming cartilage (pike). In sterlet, the hyoid and branchial CNC cells form a single hyobranchial sheet, which later segregates in concert with second pharyngeal pouch morphogenesis. Taken together, the results show that despite generally ...

Source: Developmental Biology - August 20, 2020 Category: Biology Authors: Stundl J, Pospisilova A, Matějková T, Psenicka M, Bronner ME, Cerny R Tags: Dev Biol Source Type: research