Disease relevance of egr1

• The potential for zebrafish egr1 to function as a transcriptional regulator was tested by constructing an expression vector containing zebrafish egr1 coding sequences under the control of a cytomegalovirus promoter [1].
• Such arrested retinal and lenticular development in Egr1 morphants resulted in microphthalmos [2].

High impact information on egr1

• We compared the A. burtoni egr-1 predicted protein sequence to that of other vertebrates, characterized its gene expression time course, and localized its induced expression throughout the brain [3].
• Evolutionary conservation of the egr-1 immediate-early gene response in a teleost [3].
• Males injected with a glutamate receptor agonist also had region-specific induction of egr-1 expression [3].
• Egr1 is a highly conserved zinc finger protein which plays important roles in many aspects of vertebrate development and in the adult [4].
• Between 24 and 48 hpf, Egr1 is expressed in specific domains of the hypothalamus, mesencephalon, tegmentum, pharynx, retina, otic vesicle and heart [4].

Biological context of egr1

• The zebrafish egr1 gene encodes a highly conserved, zinc-finger transcriptional regulator [1].
• The 5' region of the zebrafish egr1 gene contained a variety of transcription factor binding sites, also present in the mouse gene, for serum response factor, CREB and c-Ets [1].
• We have isolated a zebrafish egr1 homologue by screening a zebrafish genomic library with a mouse Egr1 zinc finger probe [1].
• The cDNA coding for zebrafish Egr1 was obtained and its expression pattern was examined during zebrafish embryogenesis using whole-mount in situ hybridization [4].
• DNA sequence analyses suggest that the genes cloned include the guppy homologue of Krox-20 and the zebrafish homologue of Krox-24, and that these genes diverged prior to the separation of the lineages leading to teleosts and to mammals [5].

Anatomical context of egr1

• Egr1 mRNA is first detected in adaxial cells in the presomitic mesoderm between 11 and 20 h post-fertilization (hpf), spanning the 4-24 somite stages [4].
• Later, Egr1 expression is observed only in specific brain areas, starting at 21 hpf and subsequently increasing in distinct domains of the central nervous system, e.g. in the telencephalon, diencephalon and hypothalamus [4].

Analytical, diagnostic and therapeutic context of egr1

• Southern blotting indicated the existence of a single zebrafish egr1 gene and, as in higher vertebrates, the presence of related members of a larger gene family [1].
• Sequence analysis of the zebrafish egr1 coding region revealed a high level of homology to the mouse, rat, and human Egr1 genes with the notable exception of a polymorphic, triplet nucleotide repeat sequence in the region coding for the amino terminus of the Egr1 protein [1].
• Western blot analysis and synthetic Egr1 mRNA rescue experiments confirmed whether the deformities were caused by Egr1 gene knockdown [2].

References