Project description:Brachyury (or T) is expressed in the primitive streak, tailbud and notochord of the early mouse embryo (Herrmann et al., 1990; Wilkinson et al., 1990). It plays a key role in early development: mouse embryos lacking functional Brachyury protein fail to gastrulate properly, do not form a differentiated notochord, and lack structures posterior to somite seven (Chesley, 1935; Dobrovolskaïa-Zavadskaïa, 1927; Naiche et al., 2005; Wilson et al., 1995; Wilson et al., 1993; Yanagisawa et al., 1981) We apply a ChIP-on-chip approach to identify targets of Brachyury during mouse ES cell differentiation. ES cells provide an abundant source of differentiating cells and the identification of Brachyury targets in such cells will shed light on the mechanisms of ES cell differentiation and, by analyzing the targets in the developing embryo, will reveal to what extent they provide a bone fide model of early mouse development.
Project description:Brachyury (or T) is expressed in the primitive streak, tailbud and notochord of the early mouse embryo (Herrmann et al., 1990; Wilkinson et al., 1990). It plays a key role in early development: mouse embryos lacking functional Brachyury protein fail to gastrulate properly, do not form a differentiated notochord, and lack structures posterior to somite seven (Chesley, 1935; DobrovolskaM-CM-/a-ZavadskaM-CM-/a, 1927; Naiche et al., 2005; Wilson et al., 1995; Wilson et al., 1993; Yanagisawa et al., 1981) We apply a ChIP-on-chip approach to identify targets of Brachyury during mouse ES cell differentiation. ES cells provide an abundant source of differentiating cells and the identification of Brachyury targets in such cells will shed light on the mechanisms of ES cell differentiation and, by analyzing the targets in the developing embryo, will reveal to what extent they provide a bone fide model of early mouse development. The brachyury IP expts used 3 independent biological replicates hybridised to design 1 and 2 chips per replicate Design 1 raw file AE_251471610189 + Design 2 raw file AE_251471710182 = replicate 1 Design 1 raw file AE_251471610716 + Design 2 raw file AE_251471710724 = replicate 2 Design 1 raw file AE_251471610717 + Design 2 raw file AE_251471710725 = replicate 3 in all cases IP DNA label was Cy5 and whole chromatin Cy3 Design 1 files GSM417692 Design 2 files GSM417704 Isotype control experiment performed 1 x ie design 1 raw file AE_251471610714 design 2 raw file AE_251471710722 in GSM417714 and GSM417756 IP DNA label was Cy5 and whole chromatin Cy3 as for brachyury data
Project description:Sex differences in liver gene expression are dictated by sex-differences in circulating growth hormone (GH) profiles. Presently, the pituitary hormone dependence of mouse liver gene expression was investigated on a global scale to discover sex-specific early GH response genes that might contribute to sex-specific regulation of downstream GH targets and to ascertain whether intrinsic sex-differences characterize hepatic responses to plasma GH stimulation. RNA expression analysis using 41,000-feature microarrays revealed two distinct classes of sex-specific mouse liver genes: genes subject to positive regulation (class-I) and genes subject to negative regulation by pituitary hormones (class-II). Genes activated or repressed in hypophysectomized (Hypox) mouse liver within 30-90min of GH pulse treatment at a physiological dose were identified as direct targets of GH action (early response genes). Intrinsic sex-differences in the GH responsiveness of a subset of these early response genes were observed. Notably, 45 male-specific genes, including five encoding transcriptional regulators that may mediate downstream sex-specific transcriptional responses, were rapidly induced by GH (within 30min) in Hypox male but not Hypox female mouse liver. The early GH response genes were enriched in 29 male-specific targets of the transcription factor Mef2, whose activation in hepatic stellate cells is associated with liver fibrosis leading to hepatocellular carcinoma, a male-predominant disease. Thus, the rapid activation by GH pulses of certain sex-specific genes is modulated by intrinsic sex-specific factors, which may be associated with prior hormone exposure (epigenetic mechanisms) or genetic factors that are pituitary-independent, and could contribute to sex-differences in predisposition to liver cancer or other hepatic pathophysiologies.