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Evolution of Transcriptional Regulation of Duplicated Fatty Acid‐Binding Protein Genes by PPARs in Zebrafish: a Pharmacological Approach
Author(s) -
Laprairie Robert,
DenovanWright Eileen,
Wright Jonathan
Publication year - 2015
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.29.1_supplement.619.8
Subject(s) - zebrafish , biology , promoter , gene , gene duplication , peroxisome proliferator activated receptor , reporter gene , hek 293 cells , luciferase , regulation of gene expression , genetics , gene expression , microbiology and biotechnology , transfection
Duplication of genes is thought to facilitate increasing organismal complexity. Duplicated genes may be retained in the genome if one of the duplicates acquires a novel function, or the functions of the ancestral gene are subdivided between the duplicates. A likely process for the retention of duplicates is the loss or gain of regulatory elements in the promoters of duplicated genes. The objective of this study was to explore the evolution of gene promoters using the multigene family of fatty acid‐binding proteins (fabp) in zebrafish. Previous studies had implicated the peroxisome proliferator‐activated receptors (PPARs) in the regulation of some fabp genes. The promoters of the zebrafish fabp1a , fabp1b.1 and fabp1b.2 genes, duplicated by a whole genome duplication (f abp1a and ancestral fabp1b ) followed by a tandem gene duplication ( fabp1b.1 and fabp1b.2 ), were cloned into firefly luciferase reporter plasmids, transfected into HEK cells, and tested in the presence of PPARα‐ and PPARγ‐selective agonists. Expression of these genes was further analyzed by qRT‐PCR in explant cultures of zebrafish liver and intestine treated with PPAR agonists. fabp1a expression was selectively increased by PPARα‐agonism in HEK cells and intestine. fabp1b.1 expression was selectively increased by PPARγ‐agonism in HEK cells and liver. fabp1b.2 promoter activity was not induced by PPAR modulation. The differential PPAR regulation of the duplicated fabp1 genes provide evidence of divergence of regulatory elements in these gene promoters, which may account for the retention of the duplicated fabp1 genes in the zebrafish genome. Funding from NSERC, CIHR, and Dalhousie University.