Concept explainers
A powerful approach to identifying genes of a developmental pathway is to screen for mutations that suppress or enhance the
a. A
b. In a complementary experiment, a gain
Want to see the full answer?
Check out a sample textbook solutionChapter 18 Solutions
Genetic Analysis: An Integrated Approach (3rd Edition)
- a. Describe two ways you could potentially make atransgene that would inhibit the function of a specific gene in a transgenic organism. (Hint: For oneof these techniques, recall the discussion of RNAinterference in Chapter 17.)b. Discuss how you could use either of these methodsto construct a mouse model for a recessive humangenetic condition associated with a loss of function, such as cystic fibrosis.arrow_forwarda. The eyeless gene is required for eye formation in Drosophila. It encodes a homeodomain. What would you predict about the biochemical function of the Eyeless protein?b. Where would you predict that the eyeless gene is expressed in development? How would you test your prediction? c. The Small eye and Aniridia genes of mice and humans, respectively, encode proteins with very strong sequence similarity to the fly Eyeless protein, and they are named for their effects on eye development. Devise one test to examine whether the mouse and human genes are functionally equivalent to the fly eyeless gene.arrow_forwardGene X is expressed in the developing brain, heart, andlungs of mice. Mutations that selectively affect gene Xfunction in these three tissues map to three differentregions (A, B, and C, respectively) 5′ of the X codingregion.a. Explain the nature of these mutations.b. Draw a map of the X locus consistent with the preceding information.c. How would you test the function of the A, B, and Cregions?arrow_forward
- Explain one experimental strategy for determining the functional role of the mouse HoxD-3 gene.arrow_forwardConcerning the Tools of Genetics Box Analysis ofCell-Cycle Mutants in Yeast:a. Describe how you would use replica plating ofmutagenized, haploid yeast cells to identifytemperature-sensitive (ts) mutations in essentialgenes needed for yeast growth and survival.b. Among the many ts mutations you found in part(a), how would you distinguish mutations in genesneeded for cell-cycle progression from those ingenes needed for other aspects of the life of yeasts?c. If you had a large collection of yeast cell-cyclemutants, how would you determine which of themutations are in the same gene and which are indifferent genes?arrow_forwardUsing a transgenic technique, propose an experiment to determine whether Cdx2 is sufficient for trophoblast development in the mouse embryo. Describe two results that you would expect to observe at the blastocyst stage if Cdx2 is indeed sufficient for trophoblast development. Be as specific as possible regarding the transgene that you propose for this experiment (including what gene's enhancer you would use in the transgene). Note: you do not need to explain the details of how a transgenic mouse is made. Describe the experiment in steps (Step 1: ..., Step 2: ... etc) and please keep your answer to under 150 words. tips: DONT talk about stop cassetes/memory cassetes, focus on transgenes Paper called "Cdx2 is required for correct cell fate specification and differentiation of trophectoderm in the mouse blastocyst" gave lots of results that you might see,, 6 diff ways that cdx2 is required for trophoblasts need specific gene enhancer (dont just say "expressed enhancer in genital…arrow_forward
- The Na'vi of Pandora have a neuronal gene (Na'vi) product that undergoes extensive post-translational processing that produces several protein products with a variety of tissue-specific expression patterns, cellular locations, and functions. Mutations that affect Na'vi expression, sorting, processing and function in specific neurons have been linked to altered skin color and height in Na'vi. Propose a mechanism by which: 1. The protein products of Na'vi can be tissue specific. 2. Na'vi can be processed and targeted to secretory vesicles.arrow_forwardAs an alternative to random mutagenesis, scientistscan screen for mutant phenotypes by knocking downindividual gene functions systematically using RNAi.a. Suggest ways to construct transgenes that in flieswould express RNAi to knock down a gene.b. How could you perform a mutant screen for fly genesrequired for wing development using RNAi? Howcould this screen avoid the problem of pleiotropy?arrow_forwardSometimes, genes transferred into the mouse genomeby pronuclear injection disrupt a gene at the (random)site of integration, resulting in a mutation. In one suchcase, investigators identified a recessive mutation thatcauses limb deformity in transgenic mice.a. The mutant phenotype could be due to the insertion of the transgene in a particular chromosomalsite, or a chance point mutation that arose somewhere in the mouse genome different from the integration site. How could you distinguish betweenthese two possibilities?b. The mutation in this example was in fact caused bythe insertion of the transgene. How could you usethis transgene insertion as a tag for identifying themutant gene responsible for the aberrant limbphenotype?arrow_forward
- Based on Pruisner (2013), match each of the following terms with its appropriate definition or description. PRNP gene CPEB (cytoplasmic polyadenylation element binding) protein NFT (neurofibrillary tangle) A673T-mutated AAP MAPT gene A. a "nonpathogenic prion" B. encodes PrPC (the normal cellular form of prion protein) C. encodes tau protein; mutations in this gene underlie many familial FTDs (frontotemporal dementias) D. tau-rich fibril associated with many neurodegenerative diseases E. a missense mutation in β-secretase which appears to protect against late-onset…arrow_forwardSuppose a researcher has three different Drosophila strains that have mutations in the bicoid gene called bicoid-A, bicoid-B, and bicoid-C; the wild type is designated bicoid +. To study these mutations, phenotypically normal female flies that are homozygous for the given bicoid mutation were obtained, and their oocytes were analyzed using a Northern blot to determine the size and/or amount of the bicoid mRNA and in situ hybridization to determine the bicoid mRNA location within the oocyte. A wild-type strain was also analyzed as a control. In both cases, the probe was complementary to the bicoid mRNA and the results are shown below. (Anterior is on the left; posterior is on the right.) Northern blot 1 2 - 3 4 In situ hybridization Wild type Lane 1. Wild type (bicoid*) Lane 2. bicoid-A Lane 3. bicoid-B Lane 4. bicoid-C bicoid-B bicoid-A bicoid-C Which mutation is likely to cause the embryo to develop two "anterior" ends? bicoid-B Obicoid-A bicoid-Carrow_forwardA. Deletion of the SOX9 gene leads to sex reversal resulting in a person with karyotype 46XY being phenotypically Explain the genetic basis for this. B. Describe what would happen to the phenotype of a male with a mutation in the gene encoding SF1? Explain your answer.arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning