Genetics: From Genes to Genomes, 5th edition
5th Edition
ISBN: 9780073525310
Author: Leland H. Hartwell, Michael L. Goldberg, Janice A. Fischer, Leroy Hood, Charles F. Aquadro
Publisher: McGraw-Hill Education
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Chapter 18, Problem 5P
In 1932, H. J. Muller suggested a genetic test to determine whether a particular mutation whose phenotypic effects are recessive to wild type is a null (amorphic) allele or is instead a hypomorphic allele of a gene. Muller’s test was to compare the
In a study using Muller’s test, investigators examined two recessive, loss-of-function mutant alleles of rugose named rg41 and rgγ3 . The eye morphologies displayed by flies of several genotypes are indicated in the following table. Df(1) JC70 is a large deletion that removes rugose and several genes to either side of it.
| a. | Which allele (rg41 or rgγ3) is stronger (that is, which causes the more severe mutant phenotype)? |
| b. | Which allele directs the production of higher levels of functional Rugose protein? |
| c. | How would Muller’s test discriminate between a null allele and a hypomorphic allele? Suggest a theoretical explanation for Muller’s test. Based on the results shown in the table, is either of these two mutations likely to be a null allele of rugose? If so, which one? |
| d. | Explain why an investigator would want to know whether a particular rg allele was amorphic or hypomorphic. |
| e. | Suppose that a hypermorphic rg allele exists (rghyper) that causes rough eyes due to an excess of cone cells. Could you use Muller’s genetic method to determine that the dominant allele is hypermorphic? Explain. |
| f. | Suppose an antimorphic rg allele exists (rganti). Can you think of a way to determine if a dominant mutation is antimorphic? (Hint: Assume that in addition to the chromosome with a deletion that deletes rg, a chromosome with a duplication that includes the wild-type rg gene is available.) |
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Chapter 18 Solutions
Genetics: From Genes to Genomes, 5th edition
Ch. 18 - Match each of the terms in the left column to the...Ch. 18 - a. If you were interested in the role of a...Ch. 18 - Prob. 3PCh. 18 - Flies homozygous for recessive null mutations in...Ch. 18 - In 1932, H. J. Muller suggested a genetic test to...Ch. 18 - a. Explain how you could use worms transformed...Ch. 18 - Prob. 7PCh. 18 - Sevenless is an unusual receptor protein in that...Ch. 18 - Suppose that you generated flies containing a...Ch. 18 - Drosophila researchers have collected many strains...
Ch. 18 - As an alternative to random mutagenesis,...Ch. 18 - The molecular identity of the fruit fly rugose...Ch. 18 - Prob. 13PCh. 18 - Prob. 14PCh. 18 - Prob. 15PCh. 18 - Some ts alleles are temperature sensitive during...Ch. 18 - Prob. 17PCh. 18 - Hypomorphic alleles of a pleiotropic gene...Ch. 18 - Prob. 19PCh. 18 - Prob. 20PCh. 18 - a. Explain the difference between maternal...Ch. 18 - Prob. 22PCh. 18 - Prob. 23PCh. 18 - Some genes are required both zygotically and...Ch. 18 - How would a human with a mutation in a maternal...Ch. 18 - One important demonstration that Bicoid is an...Ch. 18 - Prob. 27PCh. 18 - Prob. 28PCh. 18 - Wild-type embryos and mutant embryos lacking the...Ch. 18 - The Drosophila even-skipped eve gene has four...Ch. 18 - Prob. 31PCh. 18 - Prob. 32P
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