1 / 59

Chapter 7 Outline

Chapter 7 Outline. 7.1 Linked Genes Do Not Assort Independently, 161 7.2 Linked Genes Segregate Together, and Crossing Over Produces Recombination between Them, 162 7.3 A Three-Point Testcross Can Be Used to Map Three Linked Genes, 175

nathan
Download Presentation

Chapter 7 Outline

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 7 Outline • 7.1 Linked Genes Do Not Assort Independently, 161 • 7.2 Linked Genes Segregate Together, and Crossing Over Produces Recombination between Them, 162 • 7.3 A Three-Point Testcross Can Be Used to Map Three Linked Genes, 175 • 7.4 Physical Mapping Methods Are Used to Determine the Physical Positions of Genes on Particular Chromosomes, 185 • 7.5 Recombination Rates Exhibit Extensive Variation, 188

  2. 7.1 Linked Genes Do Not Assort Independently

  3. 7.2 Linked Genes Segregate Together and Crossing Over Produces Recombination between Them

  4. 7.2 Linked Genes Segregate Together and Crossing Over Produces Recombination between Them • Notation for Crosses with Linkage • Complete Linkage Leads to Nonrecombinant Gametes and Nonrecombinant Progeny • Crossing Over with Linked Genes Lead to Recombiant Gametes and Recombinant Progeny

  5. Calculating Recombination Frequency • Recombination frequency = (number of recombinant progeny / total number of progeny) × 100%

  6. Coupling and Repulsion Configuration of Linked Genes • Coupling (cis configuration): Wild type alleles are found on one chromosome; mutant alleles are found on the other chromosome.

  7. Coupling and Repulsion Configuration of Linked Genes • Repulsion (trans configuration): Wild-type allele and mutant allele are found on the same chromosome.

  8. Testing for Independent Assortment

  9. Concept Check 2 The following testcross produces the progeny shown: AaBb × aabb  10 AaBb, 40 aaBb, 40 aaBb, and 10 aabb. What is the percentage of recombination between the A and B loci? Were the genes in the AaBb parent in coupling or repulsion?

  10. Concept Check 2 The following testcross produces the progeny shown: AaBb × aabb  10 AaBb, 40 aaBb, 40 aaBb, and 10 aabb. What is the percent recombination between the A and B loci? Were the genes in the AaBb parent in coupling or repulsion? % recombination: 20%; genes in the AaBb parent were in repulsion

  11. Gene Mapping with Recombination Frequencies • Genetic maps are determined by recombinant frequency. • Map unit and centiMorgans

  12. Constructing a Genetic Map with Two-Point Testcrosses

  13. 7.3 A Three-Point Testcross Can Be Used to Map Three Linked Genes • Constructing a Genetic Map with the Three-Point Testcross

  14. Constructing a Genetic Map with the Three-Point Testcross • Determining the gene order • Determining the location of crossovers

  15. Concept Check 3 Write the genotypes of all recombinant and nonrecombinant progeny expected from the following three-point cross:

  16. Concept Check 3 Write the genotypes of all recombinant and nonrecombinant progeny expected from the following three-point cross: Answer:

More Related