Runx family genes in a cartilaginous fish, the elephant shark (Callorhinchus milii).
The Runx family genes encode transcription factors that play key roles in hematopoiesis, skeletogenesis and neurogenesis and are often implicated in diseases. We describe here the cloning and characterization of Runx1, Runx2, Runx3 and Runxb genes in the elephant shark (Callorhinchus milii), a member of Chondrichthyes, the oldest living group of jawed vertebrates. Through the use of alternative promoters and/or alternative splicing, each of the elephant shark Runx genes expresses multiple isoforms similar to their orthologs in human and other bony vertebrates. The expression profiles of elephant shark Runx genes are similar to those of mammalian Runx genes. The syntenic blocks of genes at the elephant shark Runx gene loci are highly conserved in human, but represented by shorter conserved blocks in zebrafish indicating a higher degree of rearrangements in this teleost fish. Analysis of promoter regions revealed conservation of binding sites for transcription factors, including two tandem binding sites for Runx that are totally conserved in the distal promoter regions of elephant shark Runx1-3. Several conserved noncoding elements (CNEs), which are putative cis-regulatory elements, and miRNA binding sites were identified in the elephant shark and human Runx gene loci. Some of these CNEs and miRNA binding sites are absent in teleost fishes such as zebrafish and fugu. In summary, our analysis reveals that the genomic organization and expression profiles of Runx genes were already complex in the common ancestor of jawed vertebrates.
Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
Giselle Sek Suan
GS
Nah
Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore.
Zhi Wei
ZW
Lim
Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore.
Boon-Hui
BH
Tay
Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore; Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; Institute of Bioengineering and Nanotechnology, Agency for Science, Technology and Research, Singapore, Singapore.
Motomi
M
Osato
Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore; Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Byrappa
B
Venkatesh
D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D050657:Core Binding Factor alpha Subunits / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome; D006801:Humans; D011401:Promoter Regions, Genetic; D012754:Sharks / Q000235:genetics*
D050657:Core Binding Factor alpha Subunits