Differential expression of same gene depending on parent of origin is referred to as - (AIIMS Nov 2014)
The phenomenon referred to as genomic imprinting leads to pereferential expression of an allele depending on its parental origin – Harrisons
o Human inherits two copies of each gene, i.e. two alleles, from homologous maternal and paternal chromosomes.
o There is no functional difference between the genes derived from mother or the father.
o But, with respect to some genes, there are functional differences between the paternal gene and maternal gene.
o These differences result from an epigenetic process, called genomic imprinting.
o In most cases, genomic imprinting selectively inactivates either the maternal or paternal allel.
1. Maternal genomic imprinting
• Selective inactivation of maternal allel
• Example is Angelman syndrome
2. Paternal genomic imprinting
• Selective inactivation ofpatemal allel.
• Example is Prader-willi syndrome.