Exam 17: Control of Gene Expression in Bacteria

Catabolite activator protein (CAP)activity is controlled by cAMP at the _____ level.

E)coli and many other bacteria of the human gut need to have fine-tuned regulation of gene expression in order to _____.

Which of the following levels of gene expression allows the most rapid response to environmental change?

CAP is said to be responsible for positive regulation of the lac operon because _____.

Use the following information when answering the corresponding question(s). The lac operon is used in countless ways for genetics research and biotechnology.One important use of the lac operon is to regulate the expression of cloned genes.In this application,some regulatory elements of the operon are fused to the cloned gene that is to be regulated.One application of such technology was reported by Cronin et al. ,The lac operator-repressor system is functional in the mouse,Genes and Development 15 (2001):1506-17.These investigators fused a portion of the lac operon to the mouse tyrosinase gene,a gene required for pigment production.This recombinant DNA,composed of E.coli lac operon sequences and the mouse tyrosinase gene,was introduced into albino mice using techniques that will be described in Chapter 19.Using the lac operon regulatory sequences,the investigators were able to regulate tyrosinase gene expression.In fact,they were able to convert albino (white)mice into brown mice.The following questions ask you to use your knowledge of the lac operon to deduce how Cronin et al.were able to regulate tyrosinase gene expression in mice. -Refer to the paragraph about the lac operon experiment by Cronin et al.Introducing the recombinant lac operon/mouse tyrosinase DNA into mice is only half of the equation for regulating tyrosinase.In addition to lac operon/mouse tyrosinase DNA,what other gene must be added to mice to regulate tyrosinase expression?

Recall from Chapter 11 that cyclin-dependent kinases are activated when they bind to a cyclin protein.This form of regulation is _____.

Use the following information when answering the corresponding question(s). The lac operon is used in countless ways for genetics research and biotechnology.One important use of the lac operon is to regulate the expression of cloned genes.In this application,some regulatory elements of the operon are fused to the cloned gene that is to be regulated.One application of such technology was reported by Cronin et al. ,The lac operator-repressor system is functional in the mouse,Genes and Development 15 (2001):1506-17.These investigators fused a portion of the lac operon to the mouse tyrosinase gene,a gene required for pigment production.This recombinant DNA,composed of E.coli lac operon sequences and the mouse tyrosinase gene,was introduced into albino mice using techniques that will be described in Chapter 19.Using the lac operon regulatory sequences,the investigators were able to regulate tyrosinase gene expression.In fact,they were able to convert albino (white)mice into brown mice.The following questions ask you to use your knowledge of the lac operon to deduce how Cronin et al.were able to regulate tyrosinase gene expression in mice. -Refer to the paragraph about the lac operon experiment by Cronin et al.If the genetically engineered albino mice were given no special treatment,how would the tyrosinase gene be expressed?

An E.coli cell without a functional lacI gene is expected to _____.

Imagine that you've added the same indicator used by Monod to E.coli colonies growing on a plate with glucose and no lactose.One colony is yellow and the remainders are white.This result suggests that cells of the yellow colony _____.

Full induction of the lac operon occurs when _____.

Use the following information when answering the corresponding question(s). The lac operon is used in countless ways for genetics research and biotechnology.One important use of the lac operon is to regulate the expression of cloned genes.In this application,some regulatory elements of the operon are fused to the cloned gene that is to be regulated.One application of such technology was reported by Cronin et al. ,The lac operator-repressor system is functional in the mouse,Genes and Development 15 (2001):1506-17.These investigators fused a portion of the lac operon to the mouse tyrosinase gene,a gene required for pigment production.This recombinant DNA,composed of E.coli lac operon sequences and the mouse tyrosinase gene,was introduced into albino mice using techniques that will be described in Chapter 19.Using the lac operon regulatory sequences,the investigators were able to regulate tyrosinase gene expression.In fact,they were able to convert albino (white)mice into brown mice.The following questions ask you to use your knowledge of the lac operon to deduce how Cronin et al.were able to regulate tyrosinase gene expression in mice. -Refer to the paragraph about the lac operon experiment by Cronin et al.The tyrosinase gene used by Cronin et al.contained the protein-coding sequence and the normal mouse regulatory sequences.These regulatory sequences provide positive control of tyrosinase transcription.If nothing else is done to this DNA and it is introduced into a mouse,tyrosinase will always be expressed.Because the goal was to regulate expression of tyrosinase,what portion of the lac operon do you think was added to this mouse gene?