Imprinting maternal

No prenatal food imprinting maternal diet from gastrulation stage on had no effect on preferences by neonate Th. sirtalis (Burghardt, 1971)... 

Lefebvre L, Viville S, Barton SC, Ishino F, Keverne EB, Surani MA 1998 Abnormal maternal behaviour and growth retardation associated with loss of the imprinted gene Mest. Nat Genet 20 163-169... 

More recent studies in Drosophila revealed that H3.3 also plays an important role in the male pronucleus after fertilization (Loppin et al. 2005). The loss of the H3.3 chaperone HIRA impairs the replacement of paternal non-histone proteins from the sperm nucleus with maternally provided histones including H3.3, while the maternal genome exclusively contains the canonical H3. Thus, H3.3 and its deposition factor HIRA function in early fertilization events and might have a role in imprinting in higher eukaryotes. 

Regulator of maternally imprinted gene 1166A>C vari- thyroidism type lA (PHP) Bartter s/Gitehnan s to multiple hormones RGS2 maximally (115-118)... 

Bastepe, M., Frohlich, L. F., Linglart, A., et al. (2005) Deletion of the NESP55 differentially methylated region causes loss of maternal GNAS imprints and pseudohypoparathyroidism type Ib. Nat. Genet 37, 25-27. 

Fig. 1. Dynamics of DNA methylation levels during mouse development. The methylation patterns of the oocyte and the rapidly demethylated after fertilization sperm create the combined methylation patterns in the early mouse zygote. During the first two to three cleavage divisions, the 5mC levels decrease further and stay low through the blastula stage. Post-implantation, the mouse embryo genome is methylated de novo the CpG islands remain mostly unmethylated. The primordial germ cells remain unmethylated. During gametogenesis specific parental (maternal or paternal) patterns of DNA methylation are established at imprinted loci (for further details see Refs. [13, 14]) (re-drawn from Ref [4]).

How are the differential patterns of methylation in the imprinted alleles established and maintained Some evidence exists that differential methylation at the paternal and maternal imprinted alleles are established independently. Knockout of Dnmt3L, a protein that shares homology with de novo DNA methyl-transferase enzymes but does not possess methyltransferase activity, results in a complete loss of the maternally imprinted DNA methylation marks [57,58]. The precise mechanisms by which the paternal methylation imprints are established are yet to be determined. 

Maternal imprinting occurs more rapidly than filial imprinting. An ungulate mother such as a goat (Klopfer and Gambale, 1966) or black-tailed deer (Miiller-Schwarze and Miiller-Schwarze, 1971) will irreversibly and exclusively... 

Klopfer, P. H. and Gambale, J. (1966). Maternal imprinting in goats the role of the chemical senses. Zeitschriftfur Tierpsychologie 23,588-592. 

A gene that is shut off when inherited from the mother is maternally imprinted. 

The precise biochemical defect for Prader-Willi syndrome is unknown, but this region of chromosome 15 encompasses an imprinting control center and at least 6 maternally imprinted genes. 

This disorder appears to involve paternal imprinting of UBE3A, encoding a ubiquitin-protein ligase so that this gene product must be produced from the maternal chromosome. 

The gene for BWS has been mapped to chromosome 11 (11 pi5), a region encompassing the gene for insulin-like growth factor II ( GV2), which is maternally imprinted and thus is expressed only when paternally inherited. 

Genomic imprinting is the mechanism by, which only one of the two parental gene copies either maternal or paternal—is expressed. Modifications in DNA and histones are the marks of genomic imprinting. There are about 50 known imprinted genes in the human genome (64). For example, the... 

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