Bradley McCollBetty R. KaoPreeyachan LourthaiKasey ChanHady WardanMark RoosjenOrane DelagneauLinden J. GearingMarnie E. BlewittSaovaros SvastiSuthat FucharoenJim VadolasRoyal Children's Hospital, MelbourneUniversity of MelbourneMahidol UniversityWalter and Eliza Hall Institute of Medical Research2018-11-092018-11-092014-01-01FASEB Journal. Vol.28, No.5 (2014), 2306-231715306860089266382-s2.0-84901013745https://repository.li.mahidol.ac.th/handle/123456789/33411Expression of fetal γ-globin in adulthood ameliorates symptoms of β-hemoglobinopathies by compensating for the mutant β-globin. Reactivation of the silenced γ-globin gene is therefore of substantial clinical interest. To study the regulation of γ-globin expression, we created the GG mice, which carry an intact 183-kb human β-globin locus modified to express enhanced green fluorescent protein (eGFP) from the Gγ-globin promoter. GG embryos express eGFP first in the yolk sac blood islands and then in the aorta-gonad mesonephros and the fetal liver, the sites of normal embryonic hematopoiesis. eGFP expression in erythroid cells peaks at E9.5 and then is rapidly silenced (>95%) and maintained at low levels into adulthood, demonstrating appropriate developmental regulation of the human β-globin locus. In vitro knockdown of the epigenetic regulator DNA methyltransferase-1 in GG primary erythroid cells increases the proportion of eGFP+cells in culture from 41.9 to 74.1%. Furthermore, eGFP fluorescence is induced >3-fold after treatment of erythroid precursors with epigenetic drugs known to induce γ-globin expression, demonstrating the suitability of the Gγ-globin eGFP reporter for evaluation of γ-globin inducers. The GG mouse model is therefore a valuable model system for genetic and pharmacologic studies of the regulation of the β-globin locus and for discovery of novel therapies for the β-hemoglobinopathies. © FASEB.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1096/fj.13-246637