RESUMEN
The transcriptional domain of chicken alpha-globin genes was shown to contain the non-globin coding erythroid-specific TMEM8 gene inducible upon terminal differentiation of erythroblasts. Acquirement by the chicken TMEM8 gene of the erythroid-specific expression correlates with its approachment to the cluster of alpha-globin genes as a result of inversion of a 170-kb chromosomal segment. The human TMEM8 gene is located far from the globin genes and is not expressed in erythroblasts. Transcription of the TMEM8 gene and adult globins in differentiated chicken erythroid cells is controlled by alternative activatory hubs sharing two regulatory elements (including the erythroid enhancer). A conclusion is made that in mature erythroblasts these regulatory elements shuttle between two different activatory hubs.
Asunto(s)
Proteínas Aviares/genética , Pollos/genética , Globinas alfa/genética , Animales , Proteínas Aviares/biosíntesis , Cromatina/genética , Islas de CpG , Elementos de Facilitación Genéticos , Eritroblastos/metabolismo , Humanos , Tejido Linfoide/metabolismo , Glicoproteínas de Membrana/biosíntesis , Glicoproteínas de Membrana/genética , Familia de Multigenes , Globinas alfa/biosíntesisRESUMEN
The ability of human embryonic stem cells (ESCs) to unlimited proliferation and huge differentiation potential makes them very attractive tool both for basic research and biological medicine. There are still little known about mechanisms that govern their differentiation or keep them in a pluripotency state. A variety of signaling events determines gene expression profiles responsible for such mechanisms activation. Protein kinases are key components of the signaling cascades. The knowledge about protein kinases expression profile in undifferentiated ESCs and embryoid bodies (EBs) will allow to understand early differentiation events. We constructed cDNA libraries containing fragments of protein kinases catalytic domain that were expressed in undifferentiated cells or EB of hESM01, hESM02 cell lines. We detected high level of MAK-V expression using Northern-blot hybridization. Semi-quantitative RT-PCR was used to compare the level of abundantly expressed kinases MAK-V, A-RAF-1, MARK3, IGF1R, NEK3 and NEK7 in undifferentiated ESCs or derived EBs.
Asunto(s)
Proteínas Quinasas/metabolismo , Células Madre/metabolismo , Animales , Northern Blotting , Dominio Catalítico/genética , Células Cultivadas , ADN Complementario/genética , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Humanos , Ratones , Quinasas Relacionadas con NIMA , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Proto-Oncogénicas A-raf/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de TiempoRESUMEN
Immunophenotype of human bone marrow mesenchymal stem cells was studied after several culturing passages and after cryopreservation. Immunocytochemical analysis showed that bone marrow mesenchymal stem cells acquired homogeneity during in vitro culturing, but initially contained heterogeneous populations.
