Genomic imprinting is a crucial genetic process that deviates from traditional Mendelian inheritance, resulting in the expression of genes based on their parental origin. This epigenetic phenomenon involves DNA methylation, which silences one allele of a gene during gametogenesis, affecting development and potentially leading to disorders like Prader-Willi and Angelman Syndromes. Imprinting is significant in both mammalian and plant biology, influencing phenotype and organismal development.
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Genomic imprinting is an epigenetic process that leads to the expression of only one allele of a gene, depending on whether it is inherited from the mother or the father
Methylation of CG Dinucleotides
DNA methylation, the addition of methyl groups to cytosine bases in CG dinucleotides, is a primary mechanism that can repress gene expression
Imprinted genes possess unique DNA sequences that serve as signals for methylation, ensuring that these genes are appropriately silenced during gametogenesis
Genomic imprinting is integral to normal development, as it regulates the monoallelic expression of genes that can significantly affect the offspring's phenotype
Disruptions in imprinting can result in congenital disorders such as Prader-Willi and Angelman Syndromes, which manifest through a spectrum of physical, developmental, and behavioral challenges
Research has shown that genomic imprinting is not exclusive to mammals and has been observed in plants, highlighting its evolutionary conservation and diverse roles in organismal development across different kingdoms
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Definition of genomic imprinting
Epigenetic process where only one allele of a gene is expressed, determined by parental origin.
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Consequence of genomic imprinting on alleles
While both maternal and paternal alleles are present, one is epigenetically silenced.
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Genomic imprinting impact on chromosomes
Affects genes on autosomal chromosomes, unrelated to sex determination, crucial in mammals.
