Northern blot analysis is performed on cellular mRNA isolated from E. coli. The probe used in the northern blot analysis hybridizes to a portion of the lacY sequence. Above is an example of the autoradiograph from northern blot analysis for a wild-type lac+ bacterial strain. In this gel, lane 1 is from bacteria grown in a medium containing only glucose (minimal medium). Lane 2 is from bacteria in a medium containing only lactose. Determine the appearance for northern blots of the bacteria listed below. In each case, lane 1 is for mRNA isolated after growth in a glucose-containing (minimal) medium, and lane 2 is for mRNA isolated after growth in a lactose-only medium.
a. lac+ bacteria with the genotype I+P+OCZ+Y+
b. lac- bacteria with the genotype I+P+O+Z−Y+
c. lac- bacteria with the genotype I+P−OCZ+Y+
d. lac+ bacteria with the genotype I−P+OCZ+Y+
e. lac- bacteria with the genotype I+P+OCZ−Y−
f. lac- bacteria with the genotype I+P+O+Z+Y+ and a mutation that prevents CAP-cAMP binding to the CAP site
Drag the appropriate labels to their respective targets. Note: not all targets will be used. Use black mark for full expression, white mark for low expression, and leave the target empty in case of no expression.
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