Role of alternative splicing of the rat erythropoietin receptor gene in normal and erythroleukemia cells

An alternatively splicing of the rat erythropoietin receptor (EpoR) gene was identified in normal and erythroleukemia cells by the reverse transcription PCR method. Insertion of a 105 bp fragment at the region corresponding to the extracellular domain of rat EpoR was found. The insert sequence, which encodes additional 21 amino acids, is similar to that previously found in the mouse EpoR gene, however, has an additional 27 bp direct repeat. Due to the presence of a stop codon in the insert, the alternative transcript is translated to a truncated and soluble form of EpoR which is preferentially expressed in liver, spleen, kidney, heart, and bone marrow cells as well as cultured erythroleukemia cells. These findings suggest that alternative splicing of the EpoR gene may play an important role in proliferation and differentiation of rat erythroid cells.