Premium
Regeneration of amphioxus oral cirri and its skeletal rods: implications for the origin of the vertebrate skeleton
Author(s) -
Kaneto Satoshi,
Wada Hiroshi
Publication year - 2011
Publication title -
journal of experimental zoology part b: molecular and developmental evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.823
H-Index - 63
eISSN - 1552-5015
pISSN - 1552-5007
DOI - 10.1002/jez.b.21411
Subject(s) - vertebrate , biology , chondrogenesis , regeneration (biology) , cartilage , skeleton (computer programming) , evolutionary biology , axial skeleton , anatomy , microbiology and biotechnology , gene , genetics
The oral cirri of amphioxus function as the first filter during feeding by eliminating unwanted large or noxious particulates. In this study, we were able to regenerate cirri following artificial amputation. This is the first firm observation of regeneration in amphioxus. Using this regeneration system, we studied skeletogenesis of the cellular skeleton of amphioxus oral cirri. During regeneration, the skeletal cells showed expression of fibrillar collagen and SoxE genes. These observations suggest that an evolutionarily conserved genetic regulatory system is involved in amphioxus cirrus and vertebrate cartilage skeletogenesis. In addition, Runx and SPARC/osteonectin expression were observed in regenerating cirral skeletal cells, indicating that cirral skeletogenesis is similar to vertebrate osteogenesis. We propose that the common ancestors of chordates possessed a genetic regulatory system that was the prototype of chondrogenesis and osteogenesis in vertebrates. Genome duplications caused divergence of this genetic regulatory system resulting in the emergence of cartilage and mineralized bone. The development of the vertebrate skeleton is an example of the functional segregation and subsequent recruitment of unique genetic materials that may account for the evolutionary diversification of novel cell types. J. Exp. Zool. (Mol. Dev. Evol.) 316:409–417, 2011 . © 2011 Wiley‐Liss, Inc.