A new evolutionary scenario for the vertebrate jaw.
The jaw is one of the earliest innovations in vertebrate history. Several recent findings suggest a scenario for jaw evolution as a progression of changes in pharyngeal developmental mechanisms. The lamprey, an extant jawless vertebrate, constitutes a model for the pre-gnathostome ancestry. Comparing expression patterns of regulatory genes between the gnathostome and lamprey embryos may enable us to get a glimpse of the essential changes that were responsible for the evolution of the jaw. We hypothesize that a specific topographical change of inductive tissue interactions to be described here brought about the jaw as an evolutionary novelty.
Shigetani
Y
Y
Division of Developmental Neurobiology, National Institute for Medical Research, Mill Hill, London, UK.
Sugahara
F
F
Kuratani
S
S
D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning; D004625:Embryo, Nonmammalian / Q000502:physiology; D005399:Fishes / Q000033:anatomy & histology / Q000145:classification; D007568:Jaw / Q000033:anatomy & histology*; D015398:Signal Transduction; D014714:Vertebrates / Q000033:anatomy & histology* / Q000145:classification