Genomic imprinting leads to preferred expression of either the maternal or paternal alleles of a subset of genes. Imprinting is essential for mammalian development, and its deregulation causes many diseases. However, the functional relevance of imprinting at the cellular level is poorly understood for most imprinted genes. We used mosaic analysis with double markers (MADM) in mice to create uni...

The interaction between maternally provided environment and offspring genotype is a major determinant of offspring development and fitness in many organisms. Recent research has demonstrated that not only genetic effects, but also epigenetic effects may be subject to modifications by the maternal environment. Genomic imprinting resulting in parent-of-origin-dependent gene expression is among th...

Within the last decade, there has been sufficient evidence to support the association of epigenetic inheritance or genomic imprinting on human chromosome 14. This has been achieved with studies of imprinting on both human chromosome 14 and mouse chromosome 12, which has the largest homology to human chromosome 14. Initial studies with mouse chromosome 12 aberrations suggested that specific phen...

Certain genes are expressed either from the maternal or the paternal genome as a result of genomic imprinting, a process that confers functional differences on parental genomes during mammalian development. In this study we focus on the cumulative effects of imprinted genes on brain development by examining the fate of androgenetic (Ag: duplicated paternal genome) and parthenogenetic/gynogeneti...

Plants and animals both exhibit parental imprinting, but do they control it the same way? Recent studies show that in Arabidopsis, as in mammals, imprinted alleles are subject to DNA methylation--but, surprisingly, the default state is silence rather than activity.

Genomic imprinting appears to be a ubiquitous process in mammals involving many chromosome segments whose affects are dependent on their parental origin. One of the challenges for clinical geneticists is to determine which disorders are manifesting imprinting effects and which families are affected. Re-evaluation of cases of chromosomal abnormalities and family histories of disease manifestatio...

Genomic imprinting, the differential expression of paternal and maternal alleles, is involved in the regulation of embryonic and fetal growth and development. In this review, we focus on the genetics of a disorder caused by a global defect in genomic imprinting, the hydatidiform mole. The ratio between the maternal and paternal genomes is critical in determining the development of both the embr...

Genes subject to genomic imprinting exist in large chromosomal domains, probably reflecting coordinate regulation of the genes within a cluster. Such regulation has been demonstrated for the H19, Igf2, and Ins2 genes that share a bifunctional imprinting control region. We have identified the Dlk1 gene as a new imprinted gene that is paternally expressed. Furthermore, we show that Dlk1 is tightl...

The evolutionary advantages of genomic imprinting are puzzling. We propose that genomic imprinting evolved as a mechanism that maximizes the interindividual variability in the rates of gene expression for dosage-sensitive loci that, with minimal unrelated deleterious effects, can alter the phenotype over a wide continuum. We hypothesize (1) that genomic imprinting provides a previously suggeste...

Inactivation of expression of the paternal allele at two maternally silent imprinted loci has recently been reported to diminish the quality of care that female mice lavish on their offspring. This suggests that there can be disagreement between the maternally and paternally derived genomes of mothers over how much care for offspring is appropriate, with the paternally derived genome favoring g...