XB-ART-901Gene Expr Patterns 2006 Apr 01;64:420-5. doi: 10.1016/j.modgep.2005.09.004.
Show Gene links Show Anatomy links
Cloning and expression pattern of the Xenopus erythropoietin receptor.
Cytokine signaling plays an important role in the survival and differentiation of vertebrate hematopoietic cells. In red blood cells, erythropoietin is a key component of the differentiation program and maintains the homeostasis of the erythroid compartment. In the adult, anemia stimulates high levels of circulating erythropoietin that drives erythropoiesis to restore normal levels of red blood cells in circulation. Erythropoietin activates the erythropoietin receptor on immature red blood cell precursors to promote their survival and differentiation. Although extensively studied in mammalian systems, a complete understanding of the function of the erythropoietin receptor during primitive erythropoiesis has been lacking. To address this problem, we have cloned the Xenopus laevis erythropoietin receptor in order to further understand the development of primitive erythropoiesis. The amphibian erythropoietin receptor shares 33% amino acid sequence identity with the mammalian erythropoietin receptors and contains the conserved extracellular ligand binding and fibronectin domains, the WSXWS motif common to cytokine receptors, and several tyrosine phosphorylation sites located on the intracellular domain of the receptor. Expression of the erythropoietin receptor is first detected by in situ hybridization in the ventral blood island during tailbud stages.
PubMed ID: 16378761
Article link: Gene Expr Patterns
Species referenced: Xenopus laevis
Genes referenced: epo epor fn1 gata1 gata2 lmo2 tal1
Article Images: [+] show captions
|Fig. 4. In situ hybridization studies on Xenopus erythropoietin receptor. (A) Albino embryos were stained for expression of EpoR at various stages during development. Expression is first detected by in situ hybridization at stage 26–28 in the ventral blood island of the developing tail bud embryo. As development progresses the levels of EpoR in the ventral blood island increase dramatically (stages 30–36). After circulation has initiated (stage 32) individual blood cells can be detected in the vasculature of the embryo. (B) In situ hybridization for hematopoietic transcription factors GATA-1, GATA-2, SCL and LMO-2. Comparison of the expression of EpoR expression with that of the hematopoietic transcription factors indicates that the EpoR most resembles the expression pattern of the erythroid factor GATA-1. The expression of EpoR is detected by in situ hybridization after the onset of expression of GATA-1 in the anterior region of the ventral blood island (compare Fig. 4A, stage 28 with Fig. 4B, stage 25).|