Chapter 15 Mutation, Recombination, and Repair

Chapter 15 Mutation, Recombination, and Repair - Mutation...

Info icon This preview shows pages 1–17. Sign up to view the full content.

View Full Document Right Arrow Icon
Mutation, Recombination, and Repair Suggested problems: #1, 2, 3, 4, 8, 10, 11, 13, 14, 16, 19, 20, 23, 24, 25, 29
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Where does genetic variation come from? 1.Mutation 2.Recombination
Image of page 2
Consequences of point mutations within genes
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Transition: purine purine pyrimidine pyrimidine Transversion: purine pyrimidine pyrimidine purine
Image of page 4
Consequences of point mutations within genes
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Other places mutations can have phenotypic consequences: 1. Mutations that affect splicing. 1. Mutations that affect promoter or regulatory regions. 1. Mutations that affect chromatin neighborhood (insulators, rearrangements to heterochromatic regions.
Image of page 6
Southern blot: detect the presence of specific sequences by probing
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Probes can be used to detect specific macromolecules Southern blot: detect DNA Northern blot: detect mRNA Western blot: detect protein (here, rather than base complementarity, an antibody that recognizes the protein is used as probe)
Image of page 8
Consequences of point mutations on gene products
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
How does mutation occur? 1. Spontaneous mutation a. spontaneous lesions b. errors in DNA replication 1. Mutagens a. base replacement b. base alteration c. base damage d. X-rays e. transposable elements
Image of page 10
Spontaneous lesions in DNA Depurination : -Loss of purine base -A mammalian cell undergoes depurination 10,000 times in a 20hr mitotic cycle! -These are repaired, but sometimes the repair results in a point mutation Deamination : -deaminated cytosine is uracil (unrepaired uracil will pair with adenine, thereby leading to a transition) -methylcytosine (of epigenetically silenced chromatin) deaminates to thymidine. Oxidative damage to bases: -thymidine glycol blocks DNA replication unless repaired - alternative guanosine form mispairs with thymidine
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Errors in DNA replication Alternative forms of bases, called tautomers, are found very rarely (bases can shift between the two forms) Keto form is the normal base Imino and enol forms are found rarely Tautomeric shift only leads to transitions pyrimidine pyrimidine purine purine
Image of page 12
Tautomeric shifts in DNA bases may cause mutations Errors in DNA replication
Image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Errors in DNA replication: insertions and deletions caused by replication slippage in highly repetetive regions
Image of page 14
Replication slippage mutations cause trinucleotide repeat diseases in humans increases in the number of three base nucleotide repeats results in disease states ie, (CGG) 6-59 = normal (CGG) >200 = diseased “premutations” in parents, with intermediate repeat numbers, make the repeats more unstable and frequently lead to disease states in their progeny ie, (CGG) 60-200
Image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
How does slippage result in diseases?
Image of page 16
Image of page 17
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern