PgmNr Z6053: Transcriptional Regulation of Neural Plate Patterning by Wnt Signaling through the Sp1 family of Transcription Factors.

Authors:
Saurav Mohanty; Arne Lekven


Institutes
Texas A & M University, College Station, TX.


Abstract:

Wnt signaling has a conserved role in anterior-posterior (A/P) patterning of the remarkably complex vertebrate brain from a very basic primordium, the neural plate, by differentially expressing downstream target genes to induce distinct neural fates. Wnt proteins originate from the blastoderm margin and diffuse anteriorly to re-pattern the default state of the anterior neural tissue to more posterior fates.  How this graded Wnt ligand in the neural plate is translated by responding cells to establish specific cell fate zones along the A/P axis is not well established. In order to understand neural posteriorization by Wnt better, we need to identify the downstream components of this pathway, for instance, the transcriptional targets of wnt signaling and their subsequent roles. We are currently focussing on two direct targets of Wnt/b-catenin signaling in Zebrafish, the sp5 and sp5-like genes. These paralogous genes potentially play an important role in mediating Wnt-dependent posterior neural plate patterning.

The sp5 genes encode zinc finger transcription factors and transcriptional regulation of sp5 orthologs by Wnt signaling is conserved in vertebrates. In spite of the compelling evidence of a significant and evolutionarily conserved relation between the sp5 genes and Wnt signaling in vertebrates, function of these genes and how they induce changes downstream of the Wnt pathway to pattern the vertebrate brain is not understood properly. We are currently studying the in vivo functions of sp5 genes by mutant analysis, utilizing the CRISPR-Cas9 genome editing tool to generate zebrafish sp5 and sp5l mutant lines. We are examining the regulation of these genes by Wnt signaling and other signaling pathways through analysis of transgenic zebrafish sp5 reporter lines developed in our lab. Finally, we want to understand how Wnt signaling regulates the transcription of several target genes downstream through the sp5 transcription factors, to pattern the neural plate during embryogenesis.



ZFIN Genetics Index
1. sp5
2. sp5l