Correct option is A
Explanation-
Statement A - Imprinting control centre (IC) harbors part of the SNRPN gene - CORRECT
The Imprinting Control Region (ICR) on chromosome 15q11-q13 includes part of the SNRPN gene, which is involved in imprinting control for the Prader-Willi and Angelman syndromes. It plays a key role in regulating parent-of-origin specific gene expression via DNA methylation.
Statement B- Imprinting of genes in an individual cannot be tissue specific - INCORRECT
Imprinting can be tissue-specific. Some imprinted genes are expressed in a parent-of-origin manner only in specific tissues, especially in the brain and placenta. Thus, this statement is false.
Statement C - Sperms and eggs exhibit identical pattern of genome methylation, except in the sex chromosomes - INCORRECT
Sperms and eggs have very different methylation patterns, not just on sex chromosomes but genome-wide. Genomic imprinting is established differentially in male and female germlines (sperm vs egg), and this differential methylation is critical to imprinting. Hence, this statement is false.
Statement D - At imprinted loci, expression depends on the parental origin - CORRECT
This is the very definition of genomic imprinting. Only one allele (either maternal or paternal) is expressed, while the other is silenced, depending on its parental origin.
Correct Option: a - A and D only
