Submitted to: Domestic Animal Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2000
Publication Date: 7/1/2000
Citation: Pearson, P.L., Smith, T.P., Sonstegard, T.S., Klemcke, H.G., Christenson, R.K., Vallet, J.L. 2000. Porcine erythropoietin receptor: molecular cloning and expression in embryonic and fetal liver. Domestic Animal Endocrinology. 19(1):25-38.
Interpretive Summary: Previous studies have shown that attempts to increase litter size in swine result in crowding within the uterus, which compromises the development of the fetus, and results in fetal loss. We have shown that the smaller fetuses at greatest risk for loss have impaired red blood cell development, resulting in anemia. The extent of red blood cell development is controlled by the hormone erythropoietin, acting via its receptor on developing red blood cells. In this study we characterized the genetic and amino acid sequence for the erythropoietin receptor, and measured expression of the gene in fetuses during pregnancy. Results indicate that changes in expression of the erythropoietin receptor coincide with fetal red blood cell development. These results provide key information needed to develop methods to improve red blood cell development in small fetuses, which in turn may provide a means to improve fetal health under crowded uterine conditions. Development of these methods should result in improvements in litter size of swine.
Technical Abstract: The full coding sequence for porcine erythropoietin receptor (EPOR) was elucidated using reverse transcription polymerase chain reaction (rtPCR) and 3' and 5' rapid amplification of cDNA ends (RACE) procedures. Total RNA collected from day 30 fetal liver was used as starting material. A 1843 bp sequence was obtained from which could be inferred a 509 amino acid protein which was 79-85% identical to the amino acid sequence of erythropoietin receptor from other species. Total RNA samples collected from white crossbred intact, white crossbred UHO and Meishan gilts on days 24, 30 and 40 of gestation were subjected to Northern blotting using porcine EPOR cDNA as probe. Results indicated that (1) a major and two minor forms of mRNA are present, (2) fetal liver mRNA concentrations for EPOR are low on day 24 of gestation and increase dramatically by day 30 and (3) mRNA concentrations for EPOR are decreased by intrauterine crowding.