Mutation and
Chromosomal Aberration
Dr. R. K. Vandre
Associate Professor
Animal Genetics and Breeding
,• Mutation is any heritable change in DNA sequence
• This may, or may not, affect the phenotype of the organism
• The term “mutation” was coined by Hugo de Vries, which is derived from La
meaning “to change”
• Mutation is a process that produces a gene or chromosome that differs from the w
• Mutation may result due to changes either on the gene or the chromosome itself
• Thus, broadly mutation maybe:
1. Gene mutation where the allele of a gene changes.
2. Chromosome mutation where segments of chromosomes, whole chromosomes,
sets of chromosomes change
, Types of Mutations
A. Type of Cell Involved
B. Mode of Origin
C. Direction of Mutation
D. Size and Quality
E. Phenotypic Effects
F. Magnitude of Phenotypic Effect
G. Loss of Function or Gain of Function
H. Type of Chromosome Involved
I. Chromosomal Mutation and Types
, A. Type of Cell Involved
1. Somatic mutations
• Mutations that are in the somatic cells of the body
• Mutations are not transmitted to progeny
• The extent of the phenotypic effect depends upon whether the mutatio
dominant or recessive (dominant mutations generally have a greater eff
• The extent of the phenotypic effect depends upon whether it occurs ea
or late in development (early arising mutations have a greater effect)
Chromosomal Aberration
Dr. R. K. Vandre
Associate Professor
Animal Genetics and Breeding
,• Mutation is any heritable change in DNA sequence
• This may, or may not, affect the phenotype of the organism
• The term “mutation” was coined by Hugo de Vries, which is derived from La
meaning “to change”
• Mutation is a process that produces a gene or chromosome that differs from the w
• Mutation may result due to changes either on the gene or the chromosome itself
• Thus, broadly mutation maybe:
1. Gene mutation where the allele of a gene changes.
2. Chromosome mutation where segments of chromosomes, whole chromosomes,
sets of chromosomes change
, Types of Mutations
A. Type of Cell Involved
B. Mode of Origin
C. Direction of Mutation
D. Size and Quality
E. Phenotypic Effects
F. Magnitude of Phenotypic Effect
G. Loss of Function or Gain of Function
H. Type of Chromosome Involved
I. Chromosomal Mutation and Types
, A. Type of Cell Involved
1. Somatic mutations
• Mutations that are in the somatic cells of the body
• Mutations are not transmitted to progeny
• The extent of the phenotypic effect depends upon whether the mutatio
dominant or recessive (dominant mutations generally have a greater eff
• The extent of the phenotypic effect depends upon whether it occurs ea
or late in development (early arising mutations have a greater effect)
