RESUMO
Protein tyrosine phosphatase epsilon (PTP epsilon)-deficient mice were generated by targeted deletion of exons 3, 4, and 5 of the Ptpre gene. Mice homozygous for this deletion (Ptpre(Delta3-5)) were fertile, bred and developed normally and exhibited no overt phenotype. However, closer examination of the function of macrophages from these mice revealed a defect in the regulation of the respiratory burst. While bacterial lipopolysaccharide (LPS) or tumour necrosis factor alpha (TNFalpha) were able to prime bone marrow-derived macrophages (BMM) from wild type (Ptpre(+)) macrophages for an enhanced respiratory burst, they were unable to do so in macrophages from PTP epsilon-deficient mice. PTP epsilon-deficient BMM also had abnormalities in cytokine production with a reduced ability to produce TNFalpha and enhanced IL-10 production in response to challenge with LPS. These findings suggest an important role for PTP epsilon in the control of macrophage function.
Assuntos
Isoenzimas/metabolismo , Macrófagos/enzimologia , Proteínas Tirosina Fosfatases/metabolismo , Animais , Sequência de Bases , Primers do DNA , Homozigoto , Isoenzimas/genética , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Fenótipo , Proteínas Tirosina Fosfatases/genética , RNA Mensageiro/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
We have generated transgenic mice by pronuclear microinjection of a murine satellite DNA-based artificial chromosome (SATAC). As 50% of the founder progeny were SATAC-positive, this demonstrates that SATAC transmission through the germline had occurred. FISH analyses of metaphase chromosomes from mitogen-activated peripheral blood lymphocytes from both the founder and progeny revealed that the SATAC was maintained as a discrete chromosome and that it had not integrated into an endogenous chromosome. To our knowledge, this is the first report of the germline transmission of a genetically engineered mammalian artificial chromosome within transgenic animals generated through pronuclear microinjection. We have also shown that murine SATACs can be similarly introduced into bovine embryos. The use of embryo microinjection to generate transgenic mammals carrying genetically engineered chromosomes provides a novel method by which the unique advantages of chromosome-based gene delivery systems can be exploited.
