Mutations

This is not a mutation.

This is a mutation…

Introduction Mutation: Changes in DNA that alter the genetic information. Mutagen: Any substance/factor that can alter the DNA (ex. Smoking, U.V light, etc.) There are 2 types of mutations: Chromosomal Mutations Gene Mutations

Mutations  changes in the sequence of DNA

Reproductive Cell Mutation Location of Mutations A. Mutation in Reproductive Cells 1. Sperm and/or eggs 2. Passed to the next generation

Somatic Cell Mutation B. Mutation in Body (Somatic) Cells 1. Any cell other than egg or sperm cells 2. May/may not cause problems for the individual with the mutation 3. All cells that come from the mutated cell will have the mutation  may cause cancer 4. Will NOT be passed onto their offspring

Gene Mutations A change in one or several nucleotides. Substitution A change in one or several nucleotides. Point Mutation: One nucleotide is affected. Ex. Substitution Frame-shift Mutation: Many nucleotides are affected. Causes a “misread” of codons after the mutation. Ex. Insertion & Deletion Insertion Deletion

Mutation Type: Nitrogen Base 1. Point Mutation – change in one nitrogen base Original DNA – TCGATTTGA Changed DNA – TCGATATGA

Example of Point Mutations

Mutation Type: Nitrogen Base 2. Frameshift Mutation – single nitrogen base is added or deleted; results in a shift in the codon reading frame Original DNA – TCGATTTGA Addition – TCGAGTTTGA Deletion – TCG_TTTGA

Chromosomal Mutations Change in the chromosome structure (location of the genes) or number of chromosomes Original Chromosome – ABCDEFGHIJ (letter = gene) Deletion  ABC_EFGHIJ **One or more genes is/are deleted

Chromosomal Deletion

Mutation Type: Chromosomal Mutations Original Chromosome – ABCDEFGHIJ Inversion  ABCFEDGHIJ ***Set of genes, on the same chromosome, are flipped/inverted

Chromosomal Inversion

Mutation Type: Chromosomal Mutations Original Chromosome – ABCDEFGHIJ Insertion  ABCDCDEFGHIJ ***One or more genes are re-inserted appear more than one time ***Inserted genes may come from any chromosome

Chromosomal Insertion

Mutation Type: Chromosomal Mutations Original Chromosome – ABCDEFGHIJ & QRSTUVWXYZ Translocation  ABCDUVWHIJ & QRSTXYZEFG **One or more genes are moved from one chromosome to another chromosome; they exchange places

Chromosomal Translocation

SO WHAT? Any addition, deletion, translocation, or kind of mutation alters the sequence or order of ACTG in DNA or where they are found…which means… YOU WON’T MAKE PROTEIN CORRECTLY

Possible Causes of Mutations A. X-rays/exposure to radioactivity B. Exposure to UV (ultraviolet) light C. Exposure to harmful chemicals (mutagens) D. Unhealthy lifestyle  smoking, drugs, etc.