Question

What is genomic imprinting? Please write an essay to explain its function and mechanism. Use an example to show how genomic imprinting affects gene expression and health.

Answer 1

Genomic imprinting-

Expression of gene is variable depending on which parent the gene come from in process known as genomic imprinting. It is an epigenetic phenomenon that causes genes to be expressed in parent of origin specific manner. It is an inheritance prosess independent of classical Mendelian inheritance. Genomic imprinting involves DNA methylation and Histone methylation without changing genetic sequence. Genomic imprinting is an example of epigenetic, or changes to DNA or chromatin these are inherited that do not affect the sequence of DNA. These epigenetic mark are established in germ line o parent and these maintained through mitotic division of cell in presence of somatic cell.

Prador-Willi and Angelman syndromes is the first example of genomic imprinting in humans.Other examples like Silver- Russell, Beckwith- Weiemann syndrome, Albright hereditary osteodystrophy and Uniparental disomy. Imprinting may cause problem in cloning, colnes having DNA that is not methylated in correct position.

The majority of imprinted gene in mammals play an key role in control of embyonic growth and development, including placenta development. It is an epigenetic phenomenon that results in monoallelic expression of gene according to parental ori