PUBLICATION

Comparative genomic analysis of teleost fish bmal genes

Authors
Wang, H.
ID
ZDB-PUB-081022-22
Date
2009
Source
Genetica   136(1): 149-161 (Journal)
Registered Authors
Wang, Han
Keywords
Circadian clocks, Conserved synteny, Genome duplication, Differential gene loss, Ratio of nonsynonymous to synonymous substitutions and relative evolutionary rates
MeSH Terms
  • Animals
  • Base Sequence
  • Circadian Rhythm/genetics*
  • Comparative Genomic Hybridization
  • Evolution, Molecular
  • Fishes/genetics*
  • Gene Duplication
  • Genome
  • Molecular Sequence Data
  • Phylogeny
  • RNA Splice Sites
PubMed
18850331 Full text @ Genetica
Abstract
Bmal1 (Brain and muscle ARNT like 1) gene is a key circadian clock gene. Tetrapods also have the second Bmal gene, Bmal2. Fruit fly has only one bmal1/cycle gene. Interrogation of the five teleost fish genome sequences coupled with phylogenetic and splice site analyses found that zebrafish have two bmal1 genes, bmal1a and bmal1b, and bmal2a; Japanese pufferfish (fugu), green spotted pufferfish (tetraodon) and Japanese medaka fish each have two bmal2 genes, bmal2a and bmal2b, and bmal1a; and three-spine stickleback have bmal1a and bmal2b. Syntenic analysis further indicated that zebrafish bmal1a/bmal1b, and fugu, tetraodon and medaka bmal2a/bmal2b are ancient duplicates. Although the dN/dS ratios of these four fish bmal duplicates are all <1, implicating they have been under purifying selection, the Tajima relative rate test showed that fugu, tetraodon and medaka bmal2a/bmal2b have asymmetric evolutionary rates, suggesting that one of these duplicates have been subject to positive selection or relaxed functional constraint. These results support the notion that teleost fish bmal genes were derived from the fish-specific genome duplication (FSGD), divergent resolution following the duplication led to retaining different ancient bmal duplicates in different fishes, which could have shaped the evolution of the complex teleost fish timekeeping mechanisms.
Genes / Markers
Figures
Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Errata and Notes