ZFIN ID: ZDB-PUB-150904-3
5′-flanking sequences of zebrafish fast myosin heavy chain genes regulate unique expression in the anterior, medial subsection and posterior tail somites of the skeletal muscle
Asaduzzaman, M., Shakur Ahammad, A.K., Asakawa, S., Kinoshita, S., Watabe, S.
Date: 2016
Source: Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology   191: 1-12 (Journal)
Registered Authors: Asaduzzaman, Md, Kinoshita, Shigeharu, Watabe, Shugo
Keywords: 5’-flanking region, Myosin heavy chain, Promoter analysis, Skeletal muscle, Transcriptional regulation, Zebrafish
MeSH Terms:
  • 5' Flanking Region/genetics*
  • Animals
  • Base Sequence
  • Conserved Sequence
  • Gene Expression Regulation, Developmental*
  • Larva/genetics
  • Molecular Sequence Data
  • Muscle, Skeletal/embryology*
  • Myosin Heavy Chains/genetics*
  • Organ Specificity
  • Promoter Regions, Genetic/genetics
  • Somites/metabolism*
  • Transcription, Genetic
  • Zebrafish/embryology*
  • Zebrafish/genetics*
  • Zebrafish Proteins/genetics
PubMed: 26335505 Full text @ Comp. Biochem. Physiol. B Biochem. Mol. Biol.
In zebrafish, expression patterns of fast muscle-specific myosin heavy chain genes are very intricate, even though the sequence homology is very high at both mRNA and protein level (96-98%). Each of these myosin heavy chain genes has its unique expression pattern in well-defined and restricted region of the skeletal muscle. However, the transcriptional regulatory mechanisms involved in their unique and restricted expression patterns have been remaining unclear. In this study, we examined the regulation of spatio-temporal expression patterns of different myhz1 (myhz1.1, myhz1.2 and myhz1.3) and myhz2 during development by using transient and stable transgenic techniques in zebrafish embryos and larvae. Embryos microinjected with different length 5'-flanking sequences of myhz1.1, myhz1.2 and myhz1.3 showed restricted and unique EGFP expression patterns in the anterior and medial subsection of somites, but all were excluded from the tail somites region. In contrast, embryos microinjected with different length 5'-flanking sequences of myhz2 showed restricted EGFP expression exclusively at posterior tail somites domain. Promoter deletion analyses demonstrated that reduced EGFP fluorescence typically correlates with the smaller 5'-flanking sequences. The immunohistochemical observation revealed that the zebrafish larvae from the transient and stable transgenic lines consistently expressed EGFP in the fast muscle fibers. r-VISTA plot identified one common conserved region of about 140 bp among myhz1.1, myhz1.2 and myhz1.3. Deletion of this conserved region from the 5'-flanking sequence of each myhz1 markedly reduced EGFP expression in their unique spatial expression patterns. Deletion mutation analysis demonstrated that myhz2 expression in the restricted tail-somite region might be mediated by Tbx (family of transcription factors having a common DNA-binding sequence known as T-box) binding elements. In summary, 5'-flanking sequences of myhz1 and myhz2 regulates their unique expression patterns in the well-defined and restricted region of the skeletal muscle in zebrafish.