The homeobox genesvoxandventare redundant repressors of dorsal fates in zebrafish

Development ◽  
2001 ◽  
Vol 128 (12) ◽  
pp. 2407-2420 ◽  
Author(s):  
Yoshiyuki Imai ◽  
Michael A. Gates ◽  
Anna E. Melby ◽  
David Kimelman ◽  
Alexander F. Schier ◽  
...  
Keyword(s):  
Early Embryo ◽  
Dorsal Side ◽  
Bmp Signaling ◽  
Loss Of Function ◽  
Dorsoventral Patterning ◽  
Patterning Defect ◽  
Morpholino Oligonucleotides ◽  
Redundant Functions ◽  
Antisense Morpholino Oligonucleotides ◽  
Antisense Morpholino

Ventralizing transcriptional repressors in the Vox/Vent family have been proposed to be important regulators of dorsoventral patterning in the early embryo. While the zebrafish genes vox (vega1) and vent (vega2) both have ventralizing activity in overexpression assays, loss-of-function studies are needed to determine whether these genes have distinct or redundant functions in dorsoventral patterning and to provide critical tests of the proposed regulatory interactions among vox, vent and other genes that act to establish the dorsoventral axis. We show that vox and vent are redundant repressors of dorsal fates in zebrafish. Mutants that lack vox function have little or no dorsoventral patterning defect, and inactivation of either vox or vent by injection of antisense morpholino oligonucleotides has little or no effect on the embryo. In contrast, embryos that lack both vox and vent function have a dorsalized phenotype. Expression of dorsal mesodermal genes, including chordin, goosecoid and bozozok, is strongly expanded in embryos that lack vox and vent function, indicating that the redundant action of vox and vent is required to restrict dorsal genes to their appropriate territories. Our genetic analysis indicates that the dorsalizing transcription factor Bozozok promotes dorsal fates indirectly, by antagonizing the expression of vox and vent. In turn, vox and vent repress chordin expression, restricting its function as an antagonist of ventral fates to the dorsal side of the embryo. Our results support a model in which BMP signaling induces the expression of ventral genes, while vox and vent act redundantly to prevent the expression of chordin, goosecoid and other dorsal genes in the lateral and ventral mesendoderm.

scholarly journals Knockdown of Laminin gamma-3 (Lamc3) impairs motoneuron guidance in the zebrafish embryo

2017 ◽  
Vol 2 ◽  
pp. 111
Author(s):  
Alexander M. J. Eve ◽  
James C. Smith
Keyword(s):  
Endothelial Cells ◽  
Zebrafish Embryo ◽  
Axonal Guidance ◽  
Loss Of Function ◽  
Cardinal Vein ◽  
Morpholino Oligonucleotides ◽  
Antisense Morpholino Oligonucleotides ◽  
Antisense Morpholino

Background: Previous work in the zebrafish embryo has shown that laminin γ-3 (lamc3) is enriched in endothelial cells marked by expression of fli1a, but the role of Lamc3 has been unknown. Methods: We use antisense morpholino oligonucleotides, and CRISPR/Cas9 mutagenesis of F0 embryos, to create zebrafish embryos in which lamc3 expression is compromised. Transgenic imaging, immunofluorescence, and in situ hybridisation reveal that Lamc3 loss-of-function affects the development of muscle pioneers, endothelial cells, and motoneurons. Results: Lamc3 is enriched in endothelial cells during zebrafish development, but it is also expressed by other tissues. Depletion of Lamc3 by use of antisense morpholino oligonucleotides perturbs formation of the parachordal chain and subsequently the thoracic duct, but Lamc3 is not required for sprouting of the cardinal vein. F0 embryos in which lamc3 expression is perturbed by a CRISPR/Cas9 approach also fail to form a parachordal chain, but we were unable to establish a stable lamc3 null line. Lamc3 is dispensable for muscle pioneer specification and for the expression of netrin-1a in these cells. Lamc3 knockdown causes netrin-1a up-regulation in the neural tube and there is increased Netrin-1 protein throughout the trunk of the embryo. Axonal guidance of rostral primary motoneurons is defective in Lamc3 knockdown embryos. Conclusions: We suggest that knockdown of Lamc3 perturbs migration of rostral primary motoneurons at the level of the horizontal myoseptum, indicating that laminin γ3 plays a role in motoneuron guidance.

scholarly journals U1 snRNP regulates cancer cell migration and invasion

2019 ◽  
Author(s):  
Jung-Min Oh ◽  
Christopher C. Venters ◽  
Chao Di ◽  
Anna Maria Pinto ◽  
Lili Wan ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Migration And Invasion ◽  
Small Nuclear Rna ◽  
Mrna Isoforms ◽  
Over Expression ◽  
Morpholino Oligonucleotides ◽  
Antisense Morpholino Oligonucleotides ◽  
Antisense Morpholino ◽  
Polyadenylation Signals

AbstractStimulated cells and cancer cells have widespread shortening of mRNA 3’-utranslated regions (3’UTRs) and switches to shorter mRNA isoforms due to usage of more proximal polyadenylation signals (PASs) in the last exon and in introns. U1 snRNA (U1), vertebrates’ most abundant non-coding (spliceosomal) small nuclear RNA, silences proximal PASs and its inhibition with antisense morpholino oligonucleotides (U1 AMO) triggers widespread mRNA shortening. Here we show that U1 AMO also modulates cancer cells’ phenotype, dose-dependently increasing migration and invasion in vitro by up to 500%, whereas U1 over-expression has the opposite effect. In addition to 3’UTR length, numerous transcriptome changes that could contribute to this phenotype are observed, including alternative splicing, and mRNA expression levels of proto-oncogenes and tumor suppressors. These findings reveal an unexpected link between U1 regulation and oncogenic and activated cell states, and suggest U1 as a potential target for their modulation.

scholarly journals U1 snRNP regulates cancer cell migration and invasion in vitro

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jung-Min Oh ◽  
Christopher C. Venters ◽  
Chao Di ◽  
Anna Maria Pinto ◽  
Lili Wan ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Migration And Invasion ◽  
Small Nuclear Rna ◽  
Mrna Isoforms ◽  
Over Expression ◽  
U1 Snrnp ◽  
Morpholino Oligonucleotides ◽  
Antisense Morpholino Oligonucleotides ◽  
Antisense Morpholino

AbstractStimulated cells and cancer cells have widespread shortening of mRNA 3’-untranslated regions (3’UTRs) and switches to shorter mRNA isoforms due to usage of more proximal polyadenylation signals (PASs) in introns and last exons. U1 snRNP (U1), vertebrates’ most abundant non-coding (spliceosomal) small nuclear RNA, silences proximal PASs and its inhibition with antisense morpholino oligonucleotides (U1 AMO) triggers widespread premature transcription termination and mRNA shortening. Here we show that low U1 AMO doses increase cancer cells’ migration and invasion in vitro by up to 500%, whereas U1 over-expression has the opposite effect. In addition to 3’UTR length, numerous transcriptome changes that could contribute to this phenotype are observed, including alternative splicing, and mRNA expression levels of proto-oncogenes and tumor suppressors. These findings reveal an unexpected role for U1 homeostasis (available U1 relative to transcription) in oncogenic and activated cell states, and suggest U1 as a potential target for their modulation.

A positive role for Short gastrulation in modulating BMP signaling during dorsoventral patterning in theDrosophilaembryo

Development ◽  
2001 ◽  
Vol 128 (19) ◽  
pp. 3831-3841 ◽  
Author(s):  
Eva Decotto ◽  
Edwin L. Ferguson
Keyword(s):  
Family Members ◽  
Positional Information ◽  
Dorsal Side ◽  
Bmp Signaling ◽  
Drosophila Embryo ◽  
Functional Difference ◽  
Ligand Specificity ◽  
Dorsoventral Patterning ◽  
Positive Role ◽  
Negative Function

Positional information in the dorsoventral axis of the Drosophila embryo is encoded by a BMP activity gradient formed by synergistic signaling between the BMP family members Decapentaplegic (DPP) and Screw (SCW). short gastrulation (sog), which is functionally homologous to Xenopus Chordin, is expressed in the ventrolateral regions of the embryo and has been shown to act as a local antagonist of BMP signaling. Here we demonstrate that SOG has a second function, which is to promote BMP signaling on the dorsal side of the embryo. We show that a weak, homozygous-viable sog mutant is enhanced to lethality by reduction in the activities of the Smad family members Mad or Medea, and that the lethality is caused by defects in the molecular specification and subsequent cellular differentiation of the dorsal-most cell type, the amnioserosa. While previous data had suggested that the negative function of SOG is directed against SCW, we present data that suggests that the positive activity of SOG is directed towards DPP. We demonstrate that Chordin shares the same apparent ligand specificity as does SOG, preferentially inhibiting SCW but not DPP activity. However, in Drosophila assays Chordin does not have the same capacity to elevate BMP signaling as does SOG, identifying a functional difference in the otherwise well conserved process of dorsoventral pattern formation in arthropods and chordates.

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