The light-producing genes of V. fischeri are organized in an operon that is under positive control by an activator protein called LuxR. Would you expect the genes of this operon to be transcribed when LuxR is bound or not bound to a DNA regulatory sequence? Explain.

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1. Step 1: Understand the concept of an operon. An operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product.
2. Step 2: Understand the concept of positive control in gene regulation. Positive control is a form of regulation in which an activator protein binds to the DNA to stimulate transcription. This is in contrast to negative control, where a repressor protein binds to the DNA to inhibit transcription.
3. Step 3: Apply these concepts to the given problem. The light-producing genes of V. fischeri are organized in an operon and are under positive control by an activator protein called LuxR. This means that LuxR acts as an activator protein, promoting the transcription of the genes in the operon.
4. Step 4: Answer the question. Given that LuxR is an activator protein, we would expect the genes of this operon to be transcribed when LuxR is bound to a DNA regulatory sequence. This is because the binding of LuxR to the DNA stimulates the transcription process.
5. Step 5: Explain the reasoning. When LuxR binds to the DNA regulatory sequence, it facilitates the binding of RNA polymerase to the promoter region of the operon, thereby initiating the transcription of the genes. If LuxR is not bound to the DNA, this process cannot occur, and the genes will not be transcribed.