{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

97_09_LB_Mutation+Repair

97_09_LB_Mutation+Repair - Bio 97 Lecture Outline Mutation...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Mutation and Repair of DNA Bio 97 ©2000-2007 Lee Bardwell Lecture Outline Mutation Classes Substitution, Insertion, Deletion, Duplication Silent, Missense, Nonsense, Frameshift Spontaneous Mutations/Damage Induced Mutations/Damage Fate of damaged DNA Mutation Rate DNA-repair defective diseases ©2007 Lee Bardwell Lecture Outline Mutation Classes Substitution, Insertion, Deletion, Duplication Silent, Missense, Nonsense, Frameshift Spontaneous Mutations/Damage Induced Mutations/Damage Fate of damaged DNA Mutation Rate DNA-repair defective diseases ©2007 Lee Bardwell Gross Mutations - Observable cytogenetically (i.e., at the level of the chromosome) Include Deletions, Duplications, Inversions, Translocations (covered first half of course) ©1999 Lee Bardwell
Image of page 1

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

View Full Document Right Arrow Icon
2 Fine-Scale Mutations - Involve less than 1000 base pairs Often, just a single base pair is changed Include substitutions, deletions, insertions, duplications ©1999 Lee Bardwell 5’----------GAATTC---------3’ 3’----------CTTAAG---------5’ Substitutions: 5’----------GA T TTC---------3’ 3’----------CT A AAG---------5’ 5’----------GA G TTC---------3’ 3’----------CT C AAG---------5’ Deletion: 5’----------GAATC----------3’ 3’----------CTTAG----------5’ ©1999 Lee Bardwell 5’----------GAATTC---------3’ 3’----------CTTAAG---------5’ Insertion: 5’----------GAA C TTC---------3’ 3’----------CTT G AAG---------5’ Duplication: 5’----------GAAT AT TC--------3’ 3’----------CTTA TA AG--------5’ ©2000 Lee Bardwell Substitutions that occur in protein-coding sequences Silent - changes a codon, but not the encoded amino acid residue possible because the code is degenerate Missense - changes the encoded residue Nonsense - an amino acid-encoding codon becomes a stop codon ©1999 Lee Bardwell
Image of page 2
3 EXAMPLES - substitutions Silent- TG T (Cys)--> TG C (Cys) GC A (Ala)--> GC N (Ala) (N = any) Missense- TG T (Cys)--> TG G (Trp) Nonsense- TG T (Cys)--> TG A (STOP) ©2000 Lee Bardwell Deletions or insertions that occur in protein- coding sequences in multiples other than 3 will cause frameshift mutations ©2000 Lee Bardwell Frameshift example NH2- Met-Thr-Leu -Lys -COOH 5’-ATG- A CC-TTG-AAA-TAA-3’ NH2-Met-Pro -COOH 5’-ATG-CCT-TGA-AAT-AA-3’ Delete A ©2000 Lee Bardwell See t h e man pat the pet cat See tem anp att hep etc at ©2001 Lee Bardwell Frameshift
Image of page 3

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

View Full Document Right Arrow Icon
4 Lecture Outline Mutation Classes Substitution, Insertion, Deletion, Duplication Silent, Missense, Nonsense, Frameshift Spontaneous Mutations/Damage Induced Mutations/Damage Fate of damaged DNA Mutation Rate DNA-repair defective diseases ©2007 Lee Bardwell Spontaneous Mutations Mistakes Replication errors Polymerase misincorporation Recombination errors Unequal crossing over, etc. Endogenous DNA Damage Spontaneous base damage Deaminations, depurinations Byproducts of metabolism Oxygen radicals that damage DNA ©2006 Lee Bardwell Spontaneous Mutations Mistakes Replication errors Polymerase misincorporation Recombination errors Unequal crossing over, etc.
Image of page 4
Image of page 5
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