Based on the data, which of the following most likely describes how the binding of proteins affects the production of Fursilla transcript?

(A) Because Fursilla transcript levels change when certain proteins are overexpressed or unexpressed in the cell, Fursilla must interfere with the other proteins.
(B) Because Fursilla transcript levels stay the same whether NEFR is overexpressed or unexpressed, NEFR must bind inhibit the production of Fursilla transcript.
(C) Because Fursilla transcript levels decrease when LSFR is unexpressed in the cell, LSFR must compete for the binding site or RNA polymerase.
(D) Because Fursilla transcript levels increase when DRKFR is unexpressed in the cell, DRKFR must compete for the binding site of RNA polymerase.

A gene responsible for production of hair pigment in dogs is called Fursilla (frsl). A map of the Fursilla locus is shown in Figure 1, below. When expressed, it results in darkly pigmented dog fur. When unexpressed, the hair is devoid of pigmentation and appears pure white. Expression of Fursilla (frsl) depends on the binding/lack of binding of several proteins: Nefur (NEFR), Lesfur (LSFR), and Dirkfur (DRKFR). Figure 2 shows the relative levels of frsl transcript as measured via RT-qPCR when each protein is overexpressed or unexpressed in the cell.

Transcribed Image Text:

mRNA levels 900 800 700 600 500 400 300 200 100 0 1220 Start site 1295 Figure 1. Map of the Fursilla region of chromosome 8 Levels of Fursilla transcript NEFR DRKFR LSFR Protein Overexpressed in the Cell mRNA levels 800 700 600 500 400 300 200 100 0 1617 Levels of Fursilla transcript NEFR DRKFR Protein Unexpressed in the Cell LSFR