ZFIN ID: ZDB-PUB-150523-5
Zebrafish Lbh-like Is Required for Otx2-mediated Photoreceptor Differentiation
Li, W.H., Zhou, L., Li, Z., Wang, Y., Shi, J.T., Yang, Y.J., Gui, J.F.
Date: 2015
Source: International journal of biological sciences   11(6): 688-700 (Journal)
Registered Authors: Li, Zhi, Wang, Yang, Zhou, Li
Keywords: otx2, Lbh-like, Notch, photoreceptor differentiation, retina development
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Apoptosis
  • Cell Differentiation/genetics*
  • Cell Proliferation
  • Eye/anatomy & histology
  • Eye/embryology
  • Gene Knockdown Techniques
  • Genetic Markers
  • Molecular Sequence Data
  • Otx Transcription Factors/genetics
  • Otx Transcription Factors/metabolism
  • Otx Transcription Factors/physiology*
  • Photoreceptor Cells, Vertebrate/cytology*
  • Sequence Alignment
  • Trans-Activators/genetics
  • Trans-Activators/metabolism
  • Trans-Activators/physiology*
  • Zebrafish/genetics
  • Zebrafish/growth & development*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
  • Zebrafish Proteins/physiology*
PubMed: 25999792 Full text @ Int. J. Biol. Sci.
The homeobox transcription factor orthodenticle homolog 2 (otx2) is supposed as an organizer that orchestrates a transcription factor network during photoreceptor development. However, its regulation in the process remains unclear. In this study, we have identified a zebrafish limb bud and heart-like gene (lbh-like), which is expressed initially at 30 hours post fertilization (hpf) in the developing brain and eyes. Lbh-like knockdown by morpholinos specifically inhibits expression of multiple photoreceptor-specific genes, such as opsins, gnat1, gnat2 and irbp. Interestingly, otx2 expression in the morphants is not significantly reduced until 32 hpf when lbh-like begins to express, but its expression level in 72 hpf morphants is higher than that in wild type embryos. Co-injection of otx2 and its downstream target neuroD mRNAs can rescue the faults in eyes of Lbh-like morphants. Combined with the results of promoter-reporter assay, we suggest that lbh-like is a new regulator of photoreceptor differentiation directly through affecting otx2 expression in zebrafish. Furthermore, knockdown of lbh-like increases the activity of Notch pathway and perturbs the balance among proliferation, differentiation and survival of photoreceptor precursors.