30. Genes translocated to the heterochromatic regions of chromosomes are silenced. In S. pombe, a translocation event was detected wherein a gene of interest was translocated to the centromere region and is silenced. Mutagenesis leading to loss of function of the followingtarget genes was done to allow expression of the gene of interest from its new locus.
A. Mutation in histone deacetylase (Clr3).
B. Mutation in histone acetyltransferase (HAT-8).
C. Mutation in histone H3 lysine 9 methyl transferase (Clr4).
D. Loss of Dicer, an RNA processing enzyme.
Which of the above events could allow the expression of this gene from the centromeric region?
(1) A, B and C
(2) A, Cand D
(3) B and C only
(4) A and C only

Summary:
In S. pombe, centromeric heterochromatin silences genes translocated to this region. Mutations in Clr3 (histone deacetylase), Clr4 (H3K9 methyltransferase), and Dicer (RNAi enzyme) disrupt heterochromatin formation and relieve silencing, enabling gene expression. In contrast, mutation of HAT-8 (histone acetyltransferase) does not affect silencing. These findings highlight the critical roles of histone modification and RNAi pathways in maintaining centromeric gene repression.

Answer:
(2) A, C and D