ZFIN ID: ZDB-PUB-081029-2
hnf1b genes in zebrafish hindbrain development
Choe, S.K., Hirsch, N., Zhang, X., and Sagerström, C.G.
Date: 2008
Source: Zebrafish   5(3): 179-187 (Journal)
Registered Authors: Choe, Seong-Kyu, Sagerström, Charles
Keywords: none
MeSH Terms:
  • Animals
  • Gene Expression Regulation, Developmental/physiology*
  • Hepatocyte Nuclear Factor 1-beta/genetics
  • Hepatocyte Nuclear Factor 1-beta/metabolism*
  • Mutation
  • Phylogeny
  • Rhombencephalon/embryology*
  • Rhombencephalon/metabolism
  • Zebrafish/embryology*
  • Zebrafish/genetics*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 18945197 Full text @ Zebrafish
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ABSTRACT
The Hnf1b transcription factor acts during formation of rhombomeres (r) 5 and 6 in the hindbrain. To determine if hnf1b is absolutely required in r5/r6, we examined the hnf1b(hi2169) and hnf1b(hi1843) retroviral insertion alleles. Hnf1b(hi2169) shows highly variable residual expression of several genes in r5/r6, but this is not due to full-length hnf1b transcripts persisting in hnf1b(hi2169) embryos, nor to hnf1bl, a novel hnf1 family member expressed in r5 that we identified. Instead, we find evidence for a virus-hnf1b fusion transcript in hnf1b(hi2169) embryos and demonstrate that morpholino-mediated knockdown of this transcript leads to near-undetectable r5 gene expression. The hnf1b(hi1843) allele has a more severe phenotype with near-undetectable expression of r5/r6 genes. We next examined if hoxb1b, which functions upstream of hnf1b in r5/r6 formation, can induce expression of r5/r6 genes in hnf1b mutants. We find that microinjected hoxb1b mRNA induces ectopic gene expression anterior to the hindbrain in hnf1b(hi2169) and hnf1b(hi1843) embryos, but cannot restore gene expression in r5/r6 of the mutants. We conclude that hnf1b(hi2169) is hypomorphic to hnf1b(hi1843) and that, while hnf1b is required for r5/r6 gene expression in the hindbrain, r5/r6 gene expression can be experimentally induced independently of hnf1b anterior to the hindbrain.
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