Concepts of Genetics (12th Edition)
12th Edition
ISBN: 9780134604718
Author: William S. Klug, Michael R. Cummings, Charlotte A. Spencer, Michael A. Palladino, Darrell Killian
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 9, Problem 18ESP
Mutations in mitochondrial DNA appear to be responsible for a number of neurological disorders, including myoclonic epilepsy and ragged- red fiber disease, Leber’s hereditary optic neuropathy, and Kearns-Sayre syndrome. In each case, the disease
- (a) Given that these are debilitating conditions, why has no cure been developed? Can you suggest a general approach that might be used to treat, or perhaps even cure, these disorders?
- (b) Compared with the vast number of mitochondria in an embryo, the number of mitochondria in an ovum is relatively small. Might such an ooplasmic mitochondrial bottleneck present an opportunity for therapy or cure? Explain.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
The DNA located inside of mitochondria exhibits approximately ten times the mutation rate seen in nuclear DNA. Provide an explanation as to why this is the case and what are the effects of this higher mutation rate of mitochondrial DNA on disease processes?
The biogenesis of functional mitochondria is dependent upon the products of both nuclear and mitochondrial genes, which poses several regulatory and logistical issues. Interestingly, many of the nuclear genes encoding mitochondrial proteins are regulated at the transcriptional level by Myc (activates transcription) and p53 (often represses transcription). Does this make sense? Why or why not?
Leber’s Hereditary Optic Neuropathy (LHON) is a disease that involves degeneration of neural cells in the retina and results in loss of central vision. The disease is caused by mutations in any one of three genes in the mitochondrial genome that encode proteins involved in oxidative phosphorylation. In a genetic counseling clinic, a woman and her husband seek advice on the potential that any of their children would be afflicted with LHON. The husband's mother and father, both exhibit symptoms of the disease, but the woman does not. What is a reasonable advising statement to make?
a.
The couple should be advised that all of their children are likely to display symptoms of LHON.
b.
There is not enough information to advise this couple.
c.
The couple should be advised that none of their children will be affected.
d.
The couple should be advised that all their male children will display symptoms of LHON, but female children will be unaffected.
e.
The couple should be…
Chapter 9 Solutions
Concepts of Genetics (12th Edition)
Ch. 9 - Chlamydomonas, a eukaryoric green alga, may be...Ch. 9 - In aerobically cultured yeast, a petite mutant is...Ch. 9 - DNA in human mitochondria encodes 22 different...Ch. 9 - Prob. 4NSTCh. 9 - Why did Marcia choose mitochondrial testing to...Ch. 9 - Marcia saw an ad on television for ancestry DNA...Ch. 9 - How much importance should we place on the results...Ch. 9 - HOW DO WE KNOW? In this chapter, we focused on...Ch. 9 - Review the Chapter Concepts list on page 196. The...Ch. 9 - Streptomycin resistance in Chlamydomonas may...
Ch. 9 - A plant may have green, white, or green-and-white...Ch. 9 - In diploid yeast strains, sporulation and...Ch. 9 - Predict the results of a cross between ascospores...Ch. 9 - In Lymnaea, what results would you expect in a...Ch. 9 - In a cross of Lymnaea, the snail contributing the...Ch. 9 - In Drosophila subobscura, the presence of a...Ch. 9 - A male mouse from a true-breeding strain of...Ch. 9 - Consider the case where a mutation occurs that...Ch. 9 - What is the endosymbiotic theory, and why is this...Ch. 9 - In an earlier Problems and Discussion section (see...Ch. 9 - Mitochondrial replacement therapy (MRT) offers a...Ch. 9 - The specification of the anteriorposterior axis in...Ch. 9 - The maternal-effect mutation bicoid (bcd) is...Ch. 9 - (a) In humans the mitochondrial genome encodes a...Ch. 9 - Mutations in mitochondrial DNA appear to be...Ch. 9 - Researchers examined a family with an interesting...Ch. 9 - Payne, B. A. et al. (2013) present evidence that a...Ch. 9 - As mentioned in Section 9.3, mtDNA accumulates...Ch. 9 - Because offspring inherit the mitochondrial genome...
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
- Leber's Hereditary Optic Neuropathy (LHON) is a disease that involves degeneration of neural cells in the retina and results in loss of central vision. The disease is caused by mutations in any one of three genes in the mitochondrial genome that encode proteins involved in oxidative phosphorylation. In a genetic counseling clinic, a woman and her husband seek advice on the potential that any of their children would be afflicted with LHON. The husband's mother and father, both exhibit symptoms of the disease, but the woman does not. What is a reasonable advising statement to make? There is not enough information to advise this couple. a. The couple should be advised that all of their children are likely to display symptoms of LHON. b. The couple should be advised that all their female children will display symptoms of LHON, but male children will be unaffected. C. The couple should be advised that all their male children will display symptoms of LHON, but female children will be…arrow_forwardLeber’s Hereditary Optic Neuropathy (LHON) is a disease that involves degeneration of neural cells in the retina and results in loss of central vision. The disease is caused by mutations in any one of three genes in the mitochondrial genome that encode proteins involved in oxidative phosphorylation. In a genetic counseling clinic, a woman and her husband seek advice on the potential that any of their children would be afflicted with LHON. The husband's mother and father, both exhibit symptoms of the disease, but the woman does not. What is a reasonable advising statement to make?arrow_forwardAntibiotics such as chloramphenicol, tetracycline, and erythromycin inhibit protein synthesis in bacteria, but have no effect on the synthesis of proteins encoded by eukaryotic nuclear genes. Cycloheximide inhibits the synthesis of proteins encoded by nuclear genes, but has no effect on bacterial protein synthesis. How might these compounds be used to determine which proteins are encoded by mitochondrial and chloroplast genomes?arrow_forward
- Many clinically relevant mitochondrial diseases are caused by mutations in mitochondrial genes affecting tRNAs. For example, one form of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) is caused by a point mutation in the gene encoding the mitochondrial tRNA whose anticodon recognizes the codons 5' UUA and 5' UUG. The mutation makes the aminoacylation of this tRNA inefficient. a. The rate of synthesis of most mitochondrial proteins is either unaffected or slightly decreased in MELAS cells, but one mitochondrial protein called NAD6 is synthesized at only 10% of the normal rate. How is it possible that the translation of this single mitochondrial protein might be affected specifically?arrow_forwardFor each of the following situations, provide a plausible explanation for how it could lead to unrestricted cell division.(a) Colon cancer cells often contain mutations in the gene encoding the prostaglandin E2 receptor. PGE2 is a growth factor required for the division of cells in the gastrointestinal tract.(b) Kaposi sarcoma, a common tumor in people with untreated AIDS, is caused by a virus carrying a gene for a protein similar to the chemokine receptors CXCR1 and CXCR2. Chemokines are cell-specific growth factors.(c) Adenovirus, a tumor virus, carries a gene for the protein E1A, which binds to the retinoblastoma protein, pRb. (d) An important feature of many oncogenes and tumor suppressor genes is their celltype specificity. For example, mutations in the PGE2 receptor are not typically found in lung tumors. Explain this observation. (Note that PGE2 acts through a GPCR in the plasma membrane.)arrow_forwardThe Saccharomyces cerevisiae nuclear gene ARG8encodes an enzyme that catalyzes a key step in biosynthesis of the amino acid arginine. This protein isnormally synthesized on cytoplasmic ribosomes, butthen is transported into mitochondria, where the enzyme conducts its functions. In 1996, T. D. Fox andhis colleagues constructed a strain of yeast in which agene encoding the Arg8 protein was itself moved intomitochondria, where functional protein could besynthesized on mitochondrial ribosomes.a. How could these investigators move the ARG8gene from the nucleus into the mitochondria, whilepermitting the synthesis of active enzyme? In whatways would the investigators need to alter theARG8 gene to allow it to function in the mitochondria instead of in the nucleus?b. Why might these researchers have wished to movethe ARG8 gene into mitochondria in the firstplace?arrow_forward
- A mutant haploid strain of Saccharomyces cerevisiae(yeast) called cox2-1 was found that was unable togrow on media containing glycerol as the sole sourceof carbon and energy. (Glycerol is a nonfermentablesubstrate for yeast.) This strain could, however, growon the fermentable substrate glucose. Researchers discovered that cox2-1 cells lack a mitochondrial proteincalled cytochrome c oxidase.a. Explain why cox2-1 cells can grow on mediumcontaining glucose but not on glycerol medium.b. When cox2-1 was crossed with a wild-type yeaststrain and the resultant diploid cells were allowedto grow mitotically, it was found that about half thediploid clones were able to grow on glycerol, whilethe other half could not. The diploid clones thatcould grow on glycerol were induced to sporulate,and they yielded tetrads with four spores that wereall able to grow on glycerol medium. In all of thesetetrads, two of the haploid progeny were of matingtype a and two of mating type α. The diploids thatcould not…arrow_forwardAbout 10% of lung cancer patients are cured of the disease, i.e., they survive 5 years after diagnosis with no evidence that the cancer has returned. Only 14% of lung cancer patients survive 5 years after diagnosis. Assume that the fraction of incurable lung cancer patients that survives a time t after diagnosis is given by exp(-kt). Find an expression for the fraction S(t) of lung cancer patients who survive a time t after being diagnosed with the disease. Be sure to determine the values of all of the constants in your answer. (Round k to four decimal places.) S(t) = What fraction of lung cancer patients survives 8 years with the disease? (Round your answer to four decimal places.) 12arrow_forwardComponents of the TIM complexes, the multi- subunit protein translocators in the mitochondrial inner membrane, are much less abundant than those of the TOM complex. They were initially identified using a genetic trick. The yeast Ura3 gene, whose product is an enzyme that is normally located in the cytosol where it is essential for synthesis of uracil, was modified so that the protein carried an import signal for the mitochondrial matrix. A population of cells carrying the modified Ura3 gene in place of the normal gene was then grown in the absence of uracil. Most cells died, but the rare cells that grew were shown to be defective for mitochondrial import. Explain how this selection identifies cells with defects in compo- nents required for import into the mitochondrial matrix. Why don’t normal cells with the modified Ura3 gene grow in the absence of uracil? Why do cells that are defective for mitochondrial import grow in the absence of uracil?Components of the TIM complexes, the multi-…arrow_forward
- You are interested in studying resistance to heavy metals and have selected the yeast Saccharomyces cerevisea to conduct your studies. You have recovered a deletion mutant that does not tolerate high concentrations of zinc (grows poorly in zinc containing media ) and have designated the mutant pgz-1 (for poor growth in zinc ). (a) What is the advantage to the type of mutant used in this work? What class of mutagen was likely use to generate pgz-1? ( b) Do you expect the PGZ gene to be expressed in your mutant? Explain.arrow_forwardWhen an injury occurs to the skin, the epithelial cells near the wound are signaled to react (by proliferating, migrating, and/or differentiating) to restore the skin in the wound. To investigate the healing process, researchers removed a small area of epithelial cells from the skin of mice, causing a wound. The researchers monitored the acetylation status of histone H4 at lysines K5, K8, and K16 on days 1, 4 and 9 after the wound was made. Cells in three regions were studied (see Figure A below): Normal epithelial cells not directly near the wound Epithelial cells adjacent to the wound The cells repopulating/repairing the wound (referred to as an “epithelial tongue” early in the process and “closed wound” later in the process) The percent of cells that were positive for H4 acetylation was recorded. The bar graph in Figure B below shows data for Days 4 and 9 for cells examined in the wound. While this experiment focused on mice, we may be able to apply the results to…arrow_forward1. Peroxisomes are organelles surrounded by a single membrane. Soluble proteins that reside within peroxisomes are imported post-translationally, and they often contain the C-terminal tripeptide SKL (serine-lysine-leucine). a) How would you confirm that a C-terminal SKL tripeptide is a peroxisomal targeting signal? b) If cells were engineered to produce a hybrid protein consisting of a mitochondrial matrix protein (including its signal sequence) followed by a C-terminal SKL signal, where in the cell would you expect the hybrid protein to be found? Explain your reasoning.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSON
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
Anatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY