Premium
Did duplication of the Tfap2 family facilitate the emergence of neural crest in evolution?
Author(s) -
Van Otterloo Eric,
Li Wei,
Medeiros Daniel Meulemans,
Cornell Robert A
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.180.4
Subject(s) - gene duplication , biology , zebrafish , neural crest , gene , vertebrate , gene family , genetics , complementation , transcription factor , gene expression , evolutionary biology , microbiology and biotechnology , phenotype
During evolution, what role does gene duplication play in the emergence of new cell types? In the phylum chordata, gene duplication has occurred and may have contributed to the emergence of vertebrate specific tissues such as neural crest (NC) and placodes. The transcription factor Activator Protein 2 (Tfap2) family provides an attractive test case because there is only one Tfap2 gene in amphioxus and multiple copies in vertebrates. Moreover, a role for Tfap2 in NC and placode induction has been shown. We find that the expression pattern of duplicated Tfap2 orthologues in vertebrates “adds up” to the expression pattern of the single copy in amphioxus, supporting the duplication degeneration complementation model of gene preservation. To test whether duplicated Tfap2 family members acquired new function prior to the emergence of NC and placode, we knocked down Tfap2 family members in zebrafish, leading to loss of NC and reducing placodes, and injected mRNA encoding amphioxus Tfap2. NC and placodes were restored in such animals, suggesting duplication of Tfap2 was not a prerequisite to the emergence of NC. Alternatively, regulatory regions of the Tfap2 gene may have been altered; we are testing this hypothesis by examining conserved tfap2 regulatory regions. These studies provide insight into changes in developmental mechanisms that accompanied the emergence of vertebrate specific cell types. Grant Funding Source : NIH GM067841 ‐ 01A3