Concept explainers
The completely synthetic yeast chromosome Syn III contains a loxP site in the 3′ UTR of every gene that is potentially nonessential to yeast survival. As you will recall from Chapter 6, loxP sites are targets of site-specific recombination. The researchers who constructed Syn III included these loxP sites as a way to “scramble” the chromosome, meaning that parts of the chromosome could easily be deleted or rearranged. The goal of these investigations is to drive the evolution of Syn III so as to define a minimal genome that can support the life of this organism. Outline the experiment the researchers would do to scramble Syn III in order to define a minimal genome.
Want to see the full answer?
Check out a sample textbook solutionChapter 12 Solutions
EBK GENETICS: FROM GENES TO GENOMES
Additional Science Textbook Solutions
Biology Science Notebook
Microbiology Fundamentals: A Clinical Approach - Standalone book
Human Anatomy & Physiology (2nd Edition)
Microbiology: An Introduction
Human Physiology
Laboratory Manual For Human Anatomy & Physiology
- The entire genome of the yeast Saccharomyces cerevisiaehas been sequenced. This sequencing has led to the identification of all the open reading frames (ORFs, gene-sizesequences with appropriate translational initiation andtermination signals) in the genome. Some of these ORFsare previously known genes with established functions;however, the remainder are unassigned reading frames(URFs). To deduce the possible functions of the URFs,they are being systematically, one at a time, convertedinto null alleles by in vitro knockout techniques. The results are as follows:15 percent are lethal when knocked out.25 percent show some mutant phenotype (alteredmorphology, altered nutrition, and so forth).60 percent show no detectable mutant phenotype at alland resemble wild type.Explain the possible molecular-genetic basis of thesethree mutant categories, inventing examples wherepossible.arrow_forwardBelow is a portion of an exon from a gene that encodes protein Y in the genome of the plant Brassica. Wildtype DNA3’ CTT AAT GCT CCG AAT CCA 5’ template strand5’ GAA TTA CGA GGC TTA GGT 3’ non-template strand A new strain (Strain X) of Brassica is identified with the same region of the gene coding for protein Y:3’ CTT AAT GCT GCG AAT CCA 5’ template strand5’ GAA TTA CGA CGC TTA GGT 3’ non-template strand Compare the sequence of Wildtype with Strain X DNA, and note the following: Whether there is a mutation. If there is a mutation, what is the type of mutation (be as specific as possible) and explain the rationale for your decision. Assuming this is the only difference between the Wildtype and Strain X, describe the potential impact of the mutation on the structure and function of the protein.arrow_forwardYou have isolated 8 mutants in yeast that fail to grow on minimal media plates but do grow when they are supplemented with Arginine. You know that Arginine is synthesized in a biochemical pathway within wild-type yeast, but you do not know how many gene products it takes for the pathway. You have all of the lines as both a and a cells and mate each strain to each other in pairwise crosses and plate them on minimal media to see if they grow. You obtain the following results with (+) representing growth, and (-) indicating no growth: a 1 5 1 a 4 5 6 7 8 How many genes are represented? O 1 3 7 O Cannot tell from the data a + + + + + • + + i 0 +, + + + • + + 7 + + + + + , . + + + + + m + + + + + + + 2 + + + + + i + -I + + . . + + +arrow_forward
- Below is a portion of an exon from a gene that encodes protein X in the genome of the plant Arabidopsis. Wildtype DNA3’ TTC AAT GCT CCG AAT ACC 5’ template strand5’ AAG TTA CGA GGC TTA TGG 3’ non-template strand A new strain (Strain B) of Arabidopsis is identified with the same region of the gene coding for protein X: 3’ TTC AAT GCT CCC AAT ACC 5’ template strand5’ AAG TTA CGA GGG TTA TGG 3’ non-template strand Compare the two DNA sequences and look for any differences. Based on what you find a. There is no mutation in Strain B compared to Strain A. b. After the point of the mutation, all the amino acids encoded by the Strain B template will be different than the Strain A protein X. c. Protein X made from the Strain B template will be much shorter than protein X made from the Strain A template d. Protein X from Strain B will have one amino acid difference that would not affect protein function. e. There is a mutation but there will not be any difference in the…arrow_forwardF ′strains in E. coli are derived from Hfr strains. In some cases, these F ′strains show a high rate of integration back into the bacterial chromosome of a second strain. Furthermore, the site of integration is often the site occupied by the sex factor in the original Hfr strain (before production of the F ′strains). Explain these results.arrow_forwardThe yeast genome has class 1 elements (Ty1, Ty2, and so forth) but no class 2 elements. What is a possible reason why DNA elements have not been successful in the yeast genome?arrow_forward
- How does homologous recombination with transfected disruption constructs can inactivate specific target genes in yeast? Explain this with the help of figure.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_forwardThe genomes of most multicellular eukaryotes encode~25,000 genes, yet their proteomes contain over 200,000proteins. Propose two processes that, taken together, account for this discrepancyarrow_forward
- Although DNA transposons are abundant in the genomes of multicellular eukaryotes, class 1 elements usually make up the largest fraction of very large genomes such as those from humans (~2500 Mb), maize (~2500 Mb), and barley (~5000 Mb). Given what you know about class 1 and class 2 elements, what is it about their distinct mechanisms of transposition that would account for this consistent difference in abundance?arrow_forwardDescribe how you would use replica plating of mutagenized, haploid yeast cells to identify temperature-sensitive (ts) mutations in essential genes needed for yeast growth and survival.arrow_forwardThe entire genome of the yeast Saccharomyces cerevisiae has been sequenced. This sequencing has led to the identification of all the open reading frames (ORFs, gene-size sequences with appropriate translational initiation and termination signals) in the genome. Some of these ORFs are previously known genes with established functions; however, the remainder are unassigned reading frames (URFs). To deduce the possible functions of the URFs, they are being systematically, one at a time, converted into null alleles by in vitro knockout techniques. The results are as follows:15 percent are lethal when knocked out.25 percent show some mutant phenotype (altered morphology, altered nutrition, and so forth).60 percent show no detectable mutant phenotype at all and resemble wild type.Explain the possible molecular-genetic basis of these three mutant categories, inventing examples where possible.arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & 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 & CompanyLaboratory 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