Zebrafish Znfl1 proteins control the expression of hoxb1b gene in the posterior neuroectoderm by acting upstream of pou5f3 and sall4 genes

J Biol Chem. 2017 Aug 4;292(31):13045-13055. doi: 10.1074/jbc.M117.777094. Epub 2017 Jun 16.

Abstract

Transcription factors play crucial roles in patterning posterior neuroectoderm. Previously, zinc finger transcription factor znfl1 was reported to be expressed in the posterior neuroectoderm of zebrafish embryos. However, its roles remain unknown. Here, we report that there are 13 copies of znfl1 in the zebrafish genome, and all the paralogues share highly identical protein sequences and cDNA sequences. When znfl1s are knocked down using a morpholino to inhibit their translation or dCas9-Eve to inhibit their transcription, the zebrafish gastrula displays reduced expression of hoxb1b, the marker gene for the posterior neuroectoderm. Further analyses reveal that diminishing znfl1s produces the decreased expressions of pou5f3, whereas overexpression of pou5f3 effectively rescues the reduced expression of hoxb1b in the posterior neuroectoderm. Additionally, knocking down znfl1s causes the reduced expression of sall4, a direct regulator of pou5f3, in the posterior neuroectoderm, and overexpression of sall4 rescues the expression of pou5f3 in the knockdown embryos. In contrast, knocking down either pou5f3 or sall4 does not affect the expressions of znfl1s Taken together, our results demonstrate that zebrafish znfl1s control the expression of hoxb1b in the posterior neuroectoderm by acting upstream of pou5f3 and sall4.

Keywords: development; homeobox; neurodevelopment; transcription factor; zebrafish; zinc finger.

MeSH terms

  • Animals
  • Biomarkers / metabolism
  • Computational Biology
  • Gastrula / drug effects
  • Gastrula / metabolism
  • Gene Dosage
  • Gene Expression Regulation, Developmental* / drug effects
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • In Situ Hybridization
  • Microinjections
  • Morpholinos / pharmacology
  • Nerve Tissue Proteins / antagonists & inhibitors
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neural Plate / drug effects
  • Neural Plate / embryology
  • Neural Plate / metabolism*
  • Neurogenesis / drug effects
  • Octamer Transcription Factor-3 / antagonists & inhibitors
  • Octamer Transcription Factor-3 / genetics
  • Octamer Transcription Factor-3 / metabolism*
  • RNA Interference
  • RNA, Antisense / pharmacology
  • RNA, Messenger / antagonists & inhibitors
  • RNA, Messenger / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Zebrafish
  • Zebrafish Proteins / antagonists & inhibitors
  • Zebrafish Proteins / chemistry
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*

Substances

  • Biomarkers
  • HOXB1 homeodomain protein
  • Homeodomain Proteins
  • Morpholinos
  • Nerve Tissue Proteins
  • Octamer Transcription Factor-3
  • Pou5f3 protein, zebrafish
  • RNA, Antisense
  • RNA, Messenger
  • Sall4 protein, zebrafish
  • Transcription Factors
  • Zebrafish Proteins
  • Znfl1 protein, zebrafish