The human insulin gene contains a number of sequences that are removed in the processing of the mRNA transcript. In spite of the fact that bacterial cells cannot excise these sequences from mRNA transcripts, explain how a gene like this can be cloned into a bacterial cell and produce insulin.

Ligase catalyzes a reaction between the 5′ phosphate and the 3′ hydroxyl groups at the ends of DNA molecules. The enzyme calf intestinal phosphatase catalyzes the removal of the 5′5′ phosphate from DNA molecules. What would be the consequence of treating a cloning vector, before ligation, with calf intestinal phosphatase?

One of the major causes of sickness, death, and economic loss in the cattle industry is Mannheimia haemolytica, which causes bovine pasteurellosis, or shipping fever. Noninvasive delivery of a vaccine using transgenic plants expressing immunogens would reduce labor costs and trauma to livestock. An early step toward developing an edible vaccine is to determine whether an injected version of an antigen (usually a derivative of the pathogen) is capable of stimulating the development of antibodies in a test organism. The following table assesses the ability of a transgenic portion of a toxin (Lkt) of M. haemolytica to stimulate development of specific antibodies in rabbits.Immunogen Injected Antibody Production in SerumLkt50*—saline extract +Lkt50*—column extract +Mock injection -*Lkt50 is a smaller derivative of Lkt that lacks all hydrophobic regions. indicates at least 50 percent neutralization of toxicity of Lkt; indicates no neutralization activity.Source: Modified from Lee et al. (2001). Infect. and Immunity 69:5786–5793.With regards to development of a usable edible vaccine, what work remains to be done?

One of the major causes of sickness, death, and economic loss in the cattle industry is Mannheimia haemolytica, which causes bovine pasteurellosis, or shipping fever. Noninvasive delivery of a vaccine using transgenic plants expressing immunogens would reduce labor costs and trauma to livestock. An early step toward developing an edible vaccine is to determine whether an injected version of an antigen (usually a derivative of the pathogen) is capable of stimulating the development of antibodies in a test organism. The following table assesses the ability of a transgenic portion of a toxin (Lkt) of M. haemolytica to stimulate development of specific antibodies in rabbits.Immunogen Injected Antibody Production in SerumLkt50*—saline extract +Lkt50*—column extract +Mock injection -*Lkt50 is a smaller derivative of Lkt that lacks all hydrophobic regions. indicates at least 50 percent neutralization of toxicity of Lkt; indicates no neutralization activity.Source: Modified from Lee et al. (2001). Infect. and Immunity 69:5786–5793.What general conclusion can you draw from the data?

The human genome is 3×10⁹bp. You wish to design a primer to amplify a specific gene in the genome. In general, what length of oligonucleotide would be sufficient to amplify a single unique sequence? To simplify your calculation, assume that all bases occur with an equal frequency.

Using animal models of human diseases can lead to insights into the cellular and genetic bases of the diseases. Duchenne muscular dystrophy (DMD) is the consequence of an X-linked recessive allele.How would you make a Drosophila model of DMD?