The Expression of the BRF1 Gene in Mice Is Normally

Multiple Choice

The expression of the BRF1 gene in mice is normally quite low, but mutations in a gene called BRF2 lead to increased expression of BRF1.You have a hunch that nucleosomes are involved in the regulation of BRF1 expression and so you investigate the position of nucleosomes over the TATA box of BRF1 in normal mice and in mice that lack either the BRF2 protein (BRF2^-) or part of histone H4 (HHF^-) (histone H4 is encoded by the HHF gene) .Table 8-27 summarizes your results.A normal functional gene is indicated by a plus sign (+) . $\begin{array}{c}\begin{array}{lll}\text { Mouse }\\\hline\text {\(B R F 2^{+}\quad \mathrm{HHF}^{+} \) }\\ \hline\text {\(B R F 2^{-}\quad H H F^{+}\) }\\\hline\text {\(\mathrm{BRF2}^{+}\quad \mathrm{HHF}^{-}\) }\\\hline\text {\(B R F 2^{-} \quad H H F^{-}\) }\\ \end{array}\begin{array}{c} \text {Nucleosome positioning}\\\hline \text {specific pattern}\\\hline \text {random}\\\hline \text {random}\\\hline \text {random}\\\end{array}\begin{array}{c}\text { Relative level of BRF1 mRNA }\\\hline 1 \\\hline 100 \\\hline 1 \\\hline 100 \end{array}\end{array}$
Table 8-27
Which of the following conclusions CANNOT be drawn from your data?

A) BRF2 is required for the repression of BRF1.
B) BRF2 is required for the specific pattern of nucleosome positions over the BRF1 upstream region.
C) The specific pattern of nucleosome positioning over the BRF1 upstream region is required for BRF1 repression.
D) The part of histone H4 missing in HHF^- mice is not required for the formation of nucleosomes.