...Vir B. Singh; Sirinapa Sribenja; Kayla E. Wilson; Kristopher M. Attwood; Joanna C. Hillman; Shilpa Pathak; Michael J. Higgins The maternally methylated KvDMR1 ICR regulates imprinted expression of a cluster of maternally expressed genes on human chromosome 11p15.5. Disruption of imprinting leads...

... maternally expressed non-coding RNAs and several paternally expressed protein-coding genes. The imprinting of this locus plays a crucial role in embryonic development and postnatal growth. At least one cis-element, the intergenic differentially methylated region (IG-DMR) is required for expression...

... conditions. These data identify an essential role for tnfa in the mutant phenotype and suggest a direct link between SAH-induced methylation defects and TNF expression in human liver disorders associated with elevated TNFα. Although heterozygous dtp larvae had no discernible phenotype, hepatic steatosis...

...Emily Clough; Woongjoon Moon; Shengxian Wang; Kathleen Smith; Tulle Hazelrigg SET domain proteins are histone lysine methyltransferases (HMTs) that play essential roles in development. Here we show for the first time that histone methylation occurs in both the germ cells and somatic cells...

... fertilization. We investigated the methylation patterns of histone H3 at lysine 9 (H3/K9), and the regulatory mechanism involved in the asymmetric remodeling of parental genomes during early preimplantation development in mice. Immunocytochemistry with an antibody that specifically recognizes methylated H3/K9...

... hypomethylated and displayed strong insulator activity – fetuses possessed very low levels of Igf2 RNA and were greatly reduced in size, being as small as Igf2 -null mutants. Furthermore, the paternal H19 allele was active. These results suggest that differential ICR methylation in the female and male germ lines...

... distinctive phenotypes such as low weight and inhibition of mitosis in the endosperm, while extra paternal genomes result in reciprocal phenotypes such as high weight and endosperm overproliferation. DNA methylation is known to be an essential component of the parental imprinting mechanism in mammals...

... and in completely ES cell-derived fetuses. Altered allelic methylation patterns were detected in all four genes, and these were consistently associated with allelic changes in gene expression. All the methylation changes that had arisen in the ES cells persisted on in vivo differentiation to fetal stages...

... of forming teratocarcinomas and coat color chimeras can be established from primordial germ cells of 8.0 days p.c. embryos and 12.5 days p.c. genital ridges. We have examined the methylation status of the putative imprinting box of the insulin-like growth factor type 2 receptor gene ( Igf2r...

...Piroska Szabó; Jeff R. Mann ABSTRACT Messenger RNA and methylation levels of four imprinted genes, H19, Igf2r, Igf-2 and Snrpn were examined by northern and Southern blotting in mouse parthenogenetic, androgenetic and normal or wild-type embryonic stem cell lines during their differentiation...

... in the X chromosome showed that, in adult somatic tissues, this transgene is subject to X-inactivation and to de novo methylation as other endogenous Xlinked genes. During mouse embryogenesis, X-linked genes show a preferential paternal inactivation in extraembryonic tissues, whereas these genes...

.... (1992). Cell 69, 67-77). Here, we show that the methylation state of the MLC1-CAT transgene in skeletal muscles is also graded along the rostrocaudal axis: methylation levels decrease and expression levels increase in the order, jaw neck chest and forelimb hindlimb. Methylation levels are also approx...

...SARAH K. HOWLETT; WOLF REIK ABSTRACT The methylation status of three highly repeated sequences was studied in sperm, eggs and preimplantation embryos with different combinations of parental chromosomes. High levels of methylation of the IAP and MUP sequence families were found in sperm and in eggs...

... the X chromosomes in the extra-embryonic tissues must be erased early in development since X-inactivation is random in the embryonic cells. Random X-chromosome inactivation leads to cellular mosaicism in expression and differential methylation of active and inactive X-linked genes. Transgene imprinting...

...Wolf Reik; Sarah K. Howlett; M. Azim Surani ABSTRACT A number of transgenes in the mouse show variation in methylation and expression phenotypes dependent on parental transmission. It appears that there exist at least two types of transgene imprinting; one is retained on an essentially homozygous...

... regions, embryo, vascular yolk sac and avascular yolk sac, were digested with methyl-specific restriction endonucleases, separated on agarose gels and end-labelled with 32 P-dCTP. The size distribution of the fragments obtained indicated three levels of methylation: high methylation of embryonic DNA...

...Marilyn Monk; Michael Boubelik; Sigrid Lehnert ABSTRACT This paper shows stage- and tissue-specific global demethylation and remethylation occurring during embryonic development. The egg genome is strikingly undermethylated and the sperm genome relatively methylated. Following a loss of genomic...