RESUMO
Erythropoietin receptor (EPOR) mRNA expression in liver, spleen, bone marrow and testes of foetal and neonatal pigs was analysed using a real-time RT-PCR assay. The results showed that early in the foetal life, EPOR expression is greatest in the liver. Later in foetal life, the spleen has the greatest expression of EPOR, whereas at 2 weeks after birth, the main expression of EPOR is found in the bone marrow. These findings contradict our earlier hypothesis that erythropoietin (EPO) acting in a paracrine fashion can account for an extensive erythropoiesis at birth, a point of time when plasma EPO concentrations are low. Results presented in the present paper suggest that the spleen or, alternatively, the bone marrow is able to respond to very low concentrations of circulating EPO around the time of birth. The testes were found to express significant amounts of EPOR. Since EPO mRNA has previously been found in the testes, a paracrine function of EPO may exist in this organ.
Assuntos
Animais Recém-Nascidos/metabolismo , Eritropoese/fisiologia , Feto/metabolismo , RNA Mensageiro/metabolismo , Receptores da Eritropoetina/metabolismo , Fatores Etários , Animais , Medula Óssea/metabolismo , Idade Gestacional , Fígado/metabolismo , Masculino , Receptores da Eritropoetina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/metabolismo , Suínos , Testículo/metabolismo , Distribuição TecidualRESUMO
Erythropoietin (EPO) mRNA expression in kidneys, liver and testes of foetal and neonatal pigs was analysed using a competitive RT-PCR assay. The results indicate that in the foetal pig, erythropoietin expression is greatest in the liver, at birth; hepatic and renal expression are nearly identical, and by 5 weeks of age there is mainly renal expression. The dynamics of the renal expression of EPO mRNA in the perinatal period provide a correlate for observations made earlier of plasma EPO concentrations. Early in foetal life (30 days after artificial insemination), the mesonephroi contained large amounts of EPO mRNA. As in the rat, the testes produced EPO mRNA in amounts comparable to the liver on a per gram tissue basis, though much less on a per organ basis.
Assuntos
Eritropoetina/genética , Feto/metabolismo , Rim/metabolismo , Fígado/metabolismo , RNA Mensageiro/metabolismo , Testículo/metabolismo , Animais , Animais Recém-Nascidos , Eritropoetina/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Masculino , Especificidade de Órgãos , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SuínosRESUMO
A set of four microsatellite markers from the USDA genetic linkage map of porcine chromosome 13 were mapped in the European Pig Gene Mapping Project (PiGMaP) reference pedigrees. A two-point linkage analysis was performed between these markers and a set of markers known to map to chromosome 13. Pairs of markers that had a lod score greater than three were used to construct a multi-point linkage map, permitting alignment of the United States Department of Agriculture (USDA) map to the PiGMaP.
