RESUMO
Today's biomedical research of excellence is mainly seen as a global phenomenon around the study of large series of samples organized with well-defined and detailed criteria regarding the identification of patients, with the specific information required in each case. This justifies the growing interest in developing cooperative networks of biobanks to minimize biases arising from heterogeneity in the quality of biological samples by means of protocols for procedures, development of common quality assurance policies, and promotion of collaborative environments. This article focuses on some basic aspects of biobank networking, including design and management. It does not try to be an exhaustive analysis but a preliminary approach to the topic, based on the author's expertise in biobank networking in Spain.
RESUMO
We have devised a strategy (called recombinase-mediated genomic replacement, RMGR) to allow the replacement of large segments (>100 kb) of the mouse genome with the equivalent human syntenic region. The technique involves modifying a mouse ES cell chromosome and a human BAC by inserting heterotypic lox sites to flank the proposed exchange interval and then using Cre recombinase to achieve segmental exchange. We have demonstrated the feasibility of this approach by replacing the mouse alpha globin regulatory domain with the human syntenic region and generating homozygous mice that produce only human alpha globin chains. Furthermore, modified ES cells can be used iteratively for functional studies, and here, as an example, we have used RMGR to produce an accurate mouse model of human alpha thalassemia. RMGR has general applicability and will overcome limitations inherent in current transgenic technology when studying the expression of human genes and modeling human genetic diseases.
Assuntos
Engenharia Genética , Genoma/genética , Sintenia/genética , Animais , Sequência de Bases , Cromossomos Artificiais Bacterianos/genética , Cromossomos de Mamíferos/genética , Marcação de Genes , Globinas/genética , Testes Hematológicos , Humanos , Hibridização in Situ Fluorescente , Camundongos , Camundongos Transgênicos , Sequências Reguladoras de Ácido Nucleico/genética , Deleção de SequênciaRESUMO
Cellular response to limiting oxygen levels is managed, in part, by the transcription factor hypoxia-inducible factor 1 (HIF-1), and the prolyl hydroxylase (PHD) family of oxygen-requiring enzymes. In the process of analyzing the expression of PHD3, we observed the presence of two alternatively processed PHD3 transcripts, designated PHD3Delta1 and PHD3Delta4 . The expression of both PHD3 and PHD3Delta1 was observed in all tissues and cell lines tested, although the expression of the novel PHD3Delta4 appeared to be restricted to primary cancer tissues. The function of PHD3Delta4 was assessed in transfection experiments showing a preserved prolyl hydroxylase activity. We would submit that PHD3 variants generated by alternative splicing may be intrinsically involved in the complex system of oxygen sensing.