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Studies have shown that increased expression of two genes called SIRT1 and SIRT2

ID: 122558 • Letter: S

Question

Studies have shown that increased expression of two genes called SIRT1 and SIRT2 is associated with chronic exposure to cocaine and contributes to drug addiction What difference in the regions of the SIRT1 and SIRT2 genes in people addicted to cocaine increases their expression? The nucleosomes become more widely spaced. Transcription factors have less access to the promoter region. RNA polymerase cannot bind better to the terminator region. The DNA bases are chemically modified with methyl groups.

Explanation / Answer

answer: Nucleosomes become more widely spaced (at the promoter region to make it more accessible to the trascription factors responsible for the transription of SIRT1 and SIRT2)

Having less access to promotor region, inability of RNA polymerase to bind to the promoter and the DNA methylation are all responsible for downregulating/ silencing the gene i.e. expression of the gene would be reduce.