Genetics: From Genes to Genomes
6th Edition
ISBN: 9781259700903
Author: Leland Hartwell Dr., Michael L. Goldberg Professor Dr., Janice Fischer, Leroy Hood Dr.
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 11, Problem 35P
The drug ivacaftor has recently been developed to treat cystic fibrosis in children with the rare G551D mutant allele of CFTR.
| a. | Do you think that ivacaftor would be effective only in patients homozygous for the G551D mutation, or might it work as well in compound heterozygotes in which one copy of chromosome 7 had G551D and the other copy a different allele of CFTR, such as the more prevalent allele ΔF508? (The protein encoded by G551D folds up properly and inserts into the cell membrane, but is inefficient in chloride ion transport. Ivacaftor increases the efficiency of G551D’s ion transport. The ΔF508 protein does not fold up properly and therefore does not get inserted into the cell membrane.) |
| b. | Why do you think ivacaftor would be more effective in children than in older cystic fibrosis patients? |
| c. | The scientists who developed ivacaftor had a model for cystic fibrosis: a line of cells that grow in culture and that are homozygous for G551D. These cells accumulate mucus at their surfaces that prevent cilia (tiny hairs on the outside of cells) from beating. Explain how the scientists could use this disease model to screen for drugs that would be effective against G551D-associated cystic fibrosis. |
| d. | Ivacaftor is used in combination with an even newer drug called lumacaftor to treat individuals homozygous for the most common CF allele, ΔF508. Lumacaftor helps the ΔF508 mutant CFTR protein fold properly so that it can insert in the cell membrane. Why do you think that neither lumacaftor nor ivacaftor alone are effective in treating ΔF508 homozygotes, while the combination of both drugs is effective? |
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
a. How would you synthesize a pentaploid?b. How would you synthesize a triploid of genotypeA/a/a?c. You have just obtained a rare recessive mutation a*in a diploid plant, which Mendelian analysis tells you isA/a*. From this plant, how would you synthesize atetraploid (4n) of genotype A/A/a*/a*?d. How would you synthesize a tetraploid of genotypeA/a/a/a?
Consider a maize plant: Genotype C/cm ; Ac/Ac+ where cm is an unstable colorless allele caused by Ds insertion. What phenotypic ratios would be produced and in what proportions when this plant is crossed with a mutant c/c Ac+/Ac+? Assume that the Ac and c loci are unlinked, that the chromosome-breakage frequency is negligible, and the C allele encodes pigment production.
A normal appearing female infant was identified with a positive newborn screen, linked to chromosome 12. Few years ago, her older sibling had
developed profound hypoglycemia, liver failure leading to coma, and subsequent irreparable brain damage, following a viral illness. The sibling was
subsequently shown by clinical testing to have the same disorder that this female infant is screened positive for.
a. What is the most likely diagnosis?
b. What biomarkers would confirm this on the newborn screening process? Describe the mechanism that causes this metabolic defect.
Chapter 11 Solutions
Genetics: From Genes to Genomes
Ch. 11 - Choose the phrase from the right column that best...Ch. 11 - Would you characterize the pattern of inheritance...Ch. 11 - Would you be more likely to find single nucleotide...Ch. 11 - A recent estimate of the rate of base...Ch. 11 - If you examine Fig. 11.5 closely, you will note...Ch. 11 - Approximately 50 million SNPs have thus far been...Ch. 11 - Mutations at simple sequence repeat SSR loci occur...Ch. 11 - Humans and gorillas last shared a common ancestor...Ch. 11 - In 2015, an international team of scientists...Ch. 11 - Using PCR, you want to amplify an approximately 1...
Ch. 11 - Prob. 11PCh. 11 - The previous problem raises several interesting...Ch. 11 - You want to make a recombinant DNA in which a PCR...Ch. 11 - You sequence a PCR product amplified from a...Ch. 11 - Prob. 15PCh. 11 - The trinucleotide repeat region of the Huntington...Ch. 11 - Sperm samples were taken from two men just...Ch. 11 - Prob. 18PCh. 11 - a. It is possible to perform DNA fingerprinting...Ch. 11 - On July 17, 1918, Tsar Nicholas II; his wife the...Ch. 11 - The figure that follows shows DNA fingerprint...Ch. 11 - Microarrays were used to determine the genotypes...Ch. 11 - A partial sequence of the wild-type HbA allele is...Ch. 11 - a. In Fig. 11.17b, PCR is performed to amplify...Ch. 11 - The following figure shows a partial microarray...Ch. 11 - Scientists were surprised to discover recently...Ch. 11 - The microarray shown in Problem 25 analyzes...Ch. 11 - The figure that follows shows the pedigree of a...Ch. 11 - One of the difficulties faced by human geneticists...Ch. 11 - Now consider a mating between consanguineous...Ch. 11 - The pedigree shown in Fig. 11.22 was crucial to...Ch. 11 - You have identified a SNP marker that in one large...Ch. 11 - The pedigrees indicated here were obtained with...Ch. 11 - Approximately 3 of the population carries a mutant...Ch. 11 - The drug ivacaftor has recently been developed to...Ch. 11 - In the high-throughput DNA sequencing protocol...Ch. 11 - A researcher sequences the whole exome of a...Ch. 11 - As explained in the text, the cause of many...Ch. 11 - Figure 11.26 portrayed the analysis of Miller...Ch. 11 - A research paper published in the summer of 2012...Ch. 11 - Table 11.2 and Fig. 11.27 together portray the...Ch. 11 - The human RefSeq of the entire first exon of a...Ch. 11 - Mutations in the HPRT1 gene in humans result in at...Ch. 11 - Prob. 44P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior history of the disease. Consider the following pedigree (the darkly colored symbols represent affected individuals): a. Circle the individual(s) in which the mutation most likely occurred. b. Is the person who is the source of the mutation affected by retinoblastoma? Justify your answer. c. Assuming that the mutant allele is fully penetrant, what is the chance that an affected individual will have an affected child?arrow_forwarda. How many generations are presented in this pedigree? b. What are the most probable genotype of III-3, IlI-5, and III-8? c. What is the probability that II- 1 and Il-2 will have another normal offspring? Show punnet square and explain your answer. d. Who among the individuals are affected?arrow_forwardMultiple crosses were made between true-breeding lines of black and yellow Labrador retrievers. All the F1 progeny were yellow. When these progeny were intercrossed, they produced an F2 consisting of 121 yellow, 9 black and 30 chocolate. What epistatic ratio and what kind of epistasis is approximated in the F2? Propose a biochemical pathway for coat color in Labrador retrievers based on the type of epistasis. Correlate each genotype with the phenotype that would occur in your pathway. Also show the frequency of each genotype. A-B- A-bb aaB- aabbarrow_forward
- Imagine a scenario in which prenatal testing of a human female fetus indicates that the baby will have a normal XX karyotype but is heterozygous for a mutation that inactivates the Xist promoter. Allele “Xr” represents the mutated version of the Xist promoter, and “XR” represents the normal version of the Xist promoter. How will this mutation affect the process of X inactivation?A. "X inactivation will still be random with both mutant and normal X chromosomes being randomly inactivated" B. "The chromosome with the mutant Xist promoter will always be active" C. "The chromosome with the mutant Xist promoter will always be inactivated" D. "The normal X chromosome (no mutation in Xist) will always be active" E. "The normal X chromosome (no mutation in Xist) will always be inactivated"arrow_forwardFemales of wild-type Strain A and males of mutant Strain B, as well as females of mutant Strain B and males of wild-type Strain A, make reciprocal crosses. Explain why reciprocal crosses are needed in genetics experiments involving Drosophila fruit flies.arrow_forwardConsider two loci A and B that are 30 cM apart on chromosome 1 in the fruit fly. A paracentric inversion is found to span about half of the distance between these loci, but not include either A or B. What is the approximate recombination frequency expected for these loci in … flies that are heterozygous for this inversion? RF(A-B) for heterozygous flies is … flies that are homozygous for this inversion? RF(A-B) for homozygous flies is …arrow_forward
- Susan’s grandfather was deaf, and passed down a hereditary form of deafness within Susan’s family as shown in Figure Q19–12.A. Is this mutation most likely to be dominant or recessive?B. Is it carried on an autosome or a sex chromosome? Why?C. A complete SNP analysis has been done for all of the 11 grandchildren (4 affected, and 7 unaffected). In comparing these 11 SNP results, how long a haplotype block would you expect to find around the critical gene? How might you detect it?arrow_forwardConsider two hypothetical recessive autosomal genes a and b, where a heterozygote is testcrossed to a double- homozygous mutant. Predict the phenotypic ratios under the following conditions: (a) a and b are located on separate autosomes. (b) a and b are linked on the same autosome but are so far apart that a crossover always occurs between them. (c) a and b are linked on the same autosome but are so close together that a crossover almost never occurs.arrow_forwardConcordance studies of twins for a neurodegenerative disorder show MZ= 46% and DZ= 15%. Further studies have shown a possible link to a gene on chromosome 9, however, there are some individuals in the study who have the allele but do not develop the disorder (group 1), and there are other individuals who do not have the allele yet develop the disorder (group 2). Amita's older sister and maternal uncle have this disorder. Currently, Amita & her 2 younger brothers do not show symptoms. Amita's paternal grandfather was rumored to have this disorder. 1. Draw the pedigree for Amita's family and determine the mode of inheritance if any. 2. Explain how the 2 groups in the study could be possible? 3. What would you tell Amita about the heritability of this disorder?arrow_forward
- In com, male sterility is controlled by maternal cytoplasmic elements. However, the presence of a nuclear fertility restorer gene (F_) restores fertility to male sterile lines. a. What are the crosses male sterile female x FF male? Give the genotypes and phenotypes of the offspring in each cross. Explain.arrow_forwardIn autotetraploid Chinese primrose (Primula sinensis L.), the gene controlling stigma color is very near the centromere of the chromosome carrying it. The allele G for green stigma is dominant to g for red stigmas. A homozygous green autotetraploid strain is crossed with a homozygous red autotetraploid strain. a. What is the genotype of the Fl1? b. Show the types of gametes the Fl's may be expected to form and derive the expected proportion of each. Show your solution. c. What phenotypic ratio of green to red is expected if: the Fl's are intercrossed? Show your solution. the Fl's are crossed with red plants? Show your solution. d. If the G locus were 50 or more map units from the centromere, what types and proportions of gametes would the Fl be expected to produce? Derive the expected F2 phenotypic ratio.arrow_forwardImagine Drosophila genes C, D, and E are autosomal genes located close to each other on the same chromosome (same assumptions as the first problem). You cross a C D E homozygote with a c d e homozygote, then cross the F1 females with a c d e homozygous male. Of 400 progeny, you observe the following phenotypes: 135 CDE 139 cde 22 cDE 18 Cde 42 CdE 38 cDe 3 cdE 3 CDe a. What is the order of the genes? Calculate the distance between genes and draw a map to get the final answer. Question 2 options: 1.CED 2. DEC 3. ECD 4. DCEarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY