The 1 and 2 genes are master regulatory genes what

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Unformatted text preview: enotype of -pheromone degradation. The 1 and 2 Genes Are Master Regulatory Genes What hypothesis could explain the roles of 1 and 2 in determining cell type? According to the proposal illustrated in Fig. A.9a, MAT is a complex locus consisting of two genes, 1 and 2. The 1 gene encodes an activator of the -specific function required to elicit the cell type. In the absence of a functional 1 product, cells are sterile, in part because they do not produce -specific proteins (a) MAT locus of α cell α1 Activator (b) MAT locus of a cell (a-specific genes) (α-specific genes) hsg Yα asg αsg Repressor α2 (haploid-specific genes) RME Meiosis asg No α1 activator. αsg not activated αsg Ya hsg a1 RME Meiosis (c) MAT loci of a / α cell Repressor α2 asg Yα α1 a1, α2 corepressors αsg No α1 activator. hsg Ya a1 Figure A.9 RME Meiosis MATa and MAT loci. Two different versions of the MAT locus, MATa and MAT , share some common DNA sequences (shown in pink) but also contain unique sequences known as Ya and Y . The presence of Ya, Y , or Ya Y in a cell has different consequences on expression of the a-specific, -specific, haploidspecific, and meiosis (RME) genes because activators and repressors are...
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This note was uploaded on 10/03/2013 for the course BI 206 taught by Professor Celenza during the Spring '08 term at BU.

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