MUTATIONS Changes in DNA that affect genetic information.

MUTATIONSMUTATIONS

Changes in Changes in DNADNA that affect genetic that affect genetic informationinformation

Gene MutationsGene Mutations

Point Mutations – changes Point Mutations – changes in in one or a fewone or a few nucleotides nucleotides SubstitutionSubstitution

THE FAT CAT ATE THE RATTHE FAT CAT ATE THE RAT THE FAT HAT ATE THE RATTHE FAT HAT ATE THE RAT

InsertionInsertion THE FAT CAT ATE THE RATTHE FAT CAT ATE THE RAT THE FAT CAT XLW ATE THE RATTHE FAT CAT XLW ATE THE RAT

DeletionDeletion THE FAT CAT ATE THE RATTHE FAT CAT ATE THE RAT THE FAT ATE THE RATTHE FAT ATE THE RAT

Missense MutationMissense Mutation

A point mutation that A point mutation that causes a change in causes a change in codoncodon

Entirely different Entirely different protein!protein!

Imagine you get a Imagine you get a phone number phone number incorrect..incorrect.. 555-5467 – Jeff

555-5367 -- Carl

Nonsense MutationNonsense Mutation

Causes a Causes a premature stop premature stop codoncodon

Stops the protein Stops the protein too earlytoo early

555 – Jeff555 - Carl

My Previous ResearchMy Previous Research

Nonsense Nonsense Mediated DecayMediated Decay

Prevent nonsense Prevent nonsense mutation from mutation from being transcribedbeing transcribed

Gene MutationsGene Mutations Frameshift Mutations – shifts Frameshift Mutations – shifts

the the reading framereading frame of the genetic of the genetic message so that the message so that the protein protein may not be able to perform its may not be able to perform its function.function. InsertionInsertion

THE FAT CAT ATE THE RATTHE FAT CAT ATE THE RAT THE FAT HCA TAT ETH ERA TTHE FAT HCA TAT ETH ERA T

DeletionDeletion THE FAT CAT ATE THE RATTHE FAT CAT ATE THE RAT TEF ATC ATA TET GER ATTEF ATC ATA TET GER AT

H

H

Chromosome MutationsChromosome Mutations Changes in number and structure of entire Changes in number and structure of entire

chromosomes chromosomes

Significance of MutationsSignificance of Mutations• Most are neutralMost are neutral

• Eye colorEye color• Birth marksBirth marks

• Some are harmfulSome are harmful• Sickle Cell AnemiaSickle Cell Anemia• Down SyndromeDown Syndrome

• Some are beneficialSome are beneficial• Sickle Cell Anemia to MalariaSickle Cell Anemia to Malaria• Immunity to HIVImmunity to HIV

What Causes Mutations?What Causes Mutations? There are two ways in which DNA can There are two ways in which DNA can

become mutated:become mutated: Mutations can be inherited. Mutations can be inherited.

Parent to childParent to child

Mutations can be acquired.Mutations can be acquired. Environmental damageEnvironmental damage Mistakes when DNA is copied Mistakes when DNA is copied

Chromosome MutationsChromosome Mutations

Down SyndromeDown Syndrome Chromosome 21 does Chromosome 21 does

not separate correctly.not separate correctly. They have 47 They have 47

chromosomes in stead chromosomes in stead of 46.of 46.

Children with Down Children with Down Syndrome develop Syndrome develop slower, may have heart slower, may have heart and stomach illnesses and stomach illnesses and vary greatly in their and vary greatly in their degree of inteligence.degree of inteligence.

Chromosome MutationsChromosome Mutations

Cri-du-chatCri-du-chat Deletion of material on 5Deletion of material on 5thth

chromosomechromosome Characterized by the cat-like Characterized by the cat-like

cry made by cri-du-chat cry made by cri-du-chat babiesbabies

Varied levels of metal Varied levels of metal handicapshandicaps

Sex Chromosome Sex Chromosome AbnormalitiesAbnormalities KlinefelterKlinefelter’’s s

SyndromeSyndrome XXY, XXYY, XXXYXXY, XXYY, XXXY MaleMale SterilitySterility Small testiclesSmall testicles Breast enlargementBreast enlargement

Sex Chromosome Sex Chromosome MutationsMutations

XXXXXX Trisomy XTrisomy X FemaleFemale Little or no visible differencesLittle or no visible differences tall staturetall stature learning disabilitieslearning disabilities limited fertility limited fertility

Mutations and DiseaseMutations and Disease

Viruses mutate fast!Viruses mutate fast! H1N1H1N1 H5N1H5N1