Types of Chromosome Mutations Chromosome Mutations Changes in

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Types of Chromosome Mutations

Types of Chromosome Mutations

Chromosome Mutations: Changes in Chromosome Structure Deletion/Deficiency Duplication Inversion A B C D E

Chromosome Mutations: Changes in Chromosome Structure Deletion/Deficiency Duplication Inversion A B C D E F A B B C A B C D E F A E D C B F A B C D E F A B C D J K G H E F D E F Translocation I I

Origins of Chromosomal Rearrangements Nonallelic Homologous Recombination (NAHR)

Origins of Chromosomal Rearrangements Nonallelic Homologous Recombination (NAHR)

Chromosome Mutations Deletion/Deficiency Duplication Inversion A B C D E F A B B

Chromosome Mutations Deletion/Deficiency Duplication Inversion A B C D E F A B B C A B C D E F A E D C B F A B C D E F A B C D J K G H E F D E F Translocation I I

Deletions can be terminal or interstitial. An intragenic deletion inactivates a gene; multigenic deletions

Deletions can be terminal or interstitial. An intragenic deletion inactivates a gene; multigenic deletions affect several genes. Homozygous condition for chromosomal deletion is often lethal. Chromosome deletion cannot revert. a a normal chromosome deletion chromosome Recessive alleles covered by a deletion are unmasked and are expressed phenotypically. This effect is known as pseudodominance. Synapsis of a normal chromosome and a deletion chromosome produces a deletion loop during meiosis. In heterozygous deletions, recombination frequencies between genes outside the deletion are lower than normal.

Deletions Cancer cells often harbor chromosome mutations. Cells of a tumor do not always

Deletions Cancer cells often harbor chromosome mutations. Cells of a tumor do not always show the same chromosome mutation. Chromosome-specific deletions are associated with certain tumors.

Chromosome Mutations Deletion/Deficiency Duplication Inversion A B C D E F A B B

Chromosome Mutations Deletion/Deficiency Duplication Inversion A B C D E F A B B C A B C D E F A E D C B F A B C D E F A B C D J K G H E F D E F Translocation I I

Duplications Arrangement of a duplication can be in tandem or reverse order. Several pairing

Duplications Arrangement of a duplication can be in tandem or reverse order. Several pairing possibilities exist in heterozygotes of a normal chromosome and a sideby-side duplication. Heterozygous condition results in a loop structure during meiosis. Duplications (and higher order duplications) can occur by unequal crossing-over after asymmetric synapsis of chromosomes.

Chromosome Mutations Deletion/Deficiency Duplication Inversion A B C D E F A B B

Chromosome Mutations Deletion/Deficiency Duplication Inversion A B C D E F A B B C A B C D E F A E D C B F A B C D E F A B C D J K G H E F D E F Translocation I I

Inversions A B C D E F G H A B F E D

Inversions A B C D E F G H A B F E D C G H pericentric inversion A B C D E F G H A B C D E G F H paracentric inversion A heterozygote for a normal chromosome and an inversion will form an inversion loop during meiosis. The number of recombinant products is reduced in inversion heterozygotes by: 1) elimination of crossing over products within the inversion loop, and 2) inhibition of pairing between homologues in the region of the inversion.

Pairing in paracentric inversion heterozygotes and resulting meiotic products. Anaphase bridge results in random

Pairing in paracentric inversion heterozygotes and resulting meiotic products. Anaphase bridge results in random breakage of chromosomal material. 2 of 4 meiotic products are not genetically balanced and will not produce viable gametes.

Pairing in pericentric inversion heterozygotes and resulting meiotic products.

Pairing in pericentric inversion heterozygotes and resulting meiotic products.

Possible effects of inversion at the molecular level No disruption of any gene. Chromosomal

Possible effects of inversion at the molecular level No disruption of any gene. Chromosomal rearrangement is the only result. Disruption of one gene by chromosomal breakage. Disruption of two genes and fusion of those two genes.

Types of Chromosome Mutations Chromosome Mutations Deletion DeficiencyTypes of Chromosome Mutations Chromosome Mutations Deletion Deficiency
Types of Chromosome Mutations Chromosome Mutations Deletion DeficiencyTypes of Chromosome Mutations Chromosome Mutations Deletion Deficiency
Types of Chromosome Mutations Chromosome Mutations Deletion DeficiencyTypes of Chromosome Mutations Chromosome Mutations Deletion Deficiency
Mutations Mutations Types of Mutations Point Mutations occursMutations Mutations Types of Mutations Point Mutations occurs
Chromosome Structure and Mutations Genetics Chromosome Mutations IncludeChromosome Structure and Mutations Genetics Chromosome Mutations Include
MUTATION SPONTANEOUS MUTATIONS INDUCED MUTATIONS MUTATIONS Mutations areMUTATION SPONTANEOUS MUTATIONS INDUCED MUTATIONS MUTATIONS Mutations are
Mutations Mutations overview Smallscale mutations Missense mutations NonsenseMutations Mutations overview Smallscale mutations Missense mutations Nonsense
Types of Chromosome Mutations Mammalian X Chromosome InactivationTypes of Chromosome Mutations Mammalian X Chromosome Inactivation
Mutations in DNA Mutations Mutations changes in theMutations in DNA Mutations Mutations changes in the
MUTATIONS Mutations Changes to DNA are called mutationsMUTATIONS Mutations Changes to DNA are called mutations
NOTES 13 3 MUTATIONS 1 MUTATIONS MUTATIONS changesNOTES 13 3 MUTATIONS 1 MUTATIONS MUTATIONS changes
NOTES 13 3 MUTATIONS 1 MUTATIONS MUTATIONS changesNOTES 13 3 MUTATIONS 1 MUTATIONS MUTATIONS changes