Fischer et al., 2019 - FoxH1 represses miR-430 during early embryonic development of zebrafish via non-canonical regulation. BMC Biology   17:61 Full text @ BMC Biol.

Fig. 4

FHD-GFP interferes with severity of the MZsur mutant phenotype. adWild-type (ab) and MZsur mutant (cd) embryos at 24hpf. col2a1a in-situ staining in wild-type (un-injected control (a) or injected with FHD-GFP (b)) shows wild-type notochord of expected width (white brackets in enlarged sections a′ and b′). In uninjected MZsur embryos the width is reduced (c′). Injection of FHD-GFP in MZsur mutants enhances the phenotype (d/d′; note reduced size and additionally discontinuity of staining). el foxa2 in-situ hybridizations show reduction of axial mesoderm formation in MZsurmutants. Injection of FHD-GFP causes a broadened axial signal in 50% of wild type embryos, but no reduction of axial cells (f), and strengthens the effect in 60% of the MZsur mutants (h). dre-miR-430 morpholinos (MOs) massively reduce axial foxa2 signals in both genotypes (lk). Co-injection of FHD-GFP and MOs also results in a decreased staining (jl) when compared to FHD-GFP injection (fh). Percentage of embryos showing the same phenotype as in the image is given (upper right). mt sox17 in-situ hybridizations show only slight reduction of endoderm after injection of MOs (qt). Number of forerunner cells (black arrow) is reduced in MZsurcontrol and after MOs injections (oqs). FHD-GFP lead to complete loss of forerunner cells (black arrow) in the majority of MZsur embryos (pt; see also Additional file : Statistical analysis of forerunner cells). Numbers of sox17-positive cells seen in dorsal view and standard deviation are given (upper right) as well as number of analyzed embryos (n) (lower right). Size bars: 200 μm. γ value was changed to 0.8 in each picture
 

Fig. 5

FoxH1 blocks maternal clearance of cd82b and jade1. ab RT-qPCR analysis of cd82b (a) or jade1 (b) in embryos at 50% epiboly with indicated genetic background. Massive reduction of expression is shown in MZsur mutants which cannot be rescued by injection of FHD-VP16 mRNA but is rescued via injection of foxH1WT mRNA. Error bars indicate standard error (SEM) from 2 biological replicates. Calculation of relative normalized expression, standard error, and significance was made with the Bio-Rad CFX Manager 3.1 software (***p < 0.001; n.s. p ≥ 0.05). For individual values, see also Additional file : Individual qPCR values. cf WISH for cd82b and jade1 in wild type embryos (ce) shows staining at sphere stage, but not at shield stage when miR-430 becomes active (c′, e′). In MZsur mutants (df), weak or no staining is visible for all stages indicating the negative role of FoxH1 in regulating miR-430 activity at early embryonic stages. Size bars 200 μm
 

EXPRESSION / LABELING:
Genes:
Fish:
Anatomical Term:
Stage Range: Sphere to Shield
PHENOTYPE:
Fish:
Observed In:
Stage Range: Sphere to 50%-epiboly
Acknowledgments:
ZFIN wishes to thank the journal BMC Biology for permission to reproduce figures from this article. Please note that this material may be protected by copyright. Full text @ BMC Biol.