Pleiotropic functions of embryonic sonic hedgehog expression link jaw and taste bud amplification with eye loss during cavefish evolution.

ABSTRACT: This study addresses the role of sonic hedgehog (shh) in increasing oral-pharyngeal constructive traits (jaws and taste buds) at the expense of eyes in the blind cavefish Astyanax mexicanus. In cavefish embryos, eye primordia degenerate under the influence of hyperactive Shh signaling. In concert, cavefish show amplified jaw size and taste bud numbers as part of a change in feeding behavior. To determine whether pleiotropic effects of hyperactive Shh signaling link these regressive and constructive traits, shh expression was compared during late development of the surface-dwelling (surface fish) and cave-dwelling (cavefish) forms of Astyanax. After an initial expansion along the midline of early embryos, shh was elevated in the oral-pharyngeal region in cavefish and later was confined to t

SUBMITTER: Yamamoto Y 

PROVIDER: S-EPMC3592972 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature