Gene mutation and its types

Gene mutation, types, significance & its effect in agriculture and allied sciences.

1. GENE MUTATION & ITS
TYPES
Presented by: CS KAZIPYO
15MSCGPB001 III Semester
M.Sc (Ag) Genetics & Plant
Breeding

3. HOW DO MUTATION OCCURHOW DO MUTATION OCCUR
•Mutations may be natural or induced
and may be occur at chromosome level
or at gene or molecular level
•Spontaneous mutation is due to natural
causes like errors in DNA application.
•Induced mutation is caused by artificial
agents called mutagens (Physical
radiation or Chemical compound).

4. TYPES OF GENE
MUTATION

Point Mutation
 Substitution
 Insertion
 Deletion
 Frameshift

6. Point Mutation
•Missense Mutation:
DNA → RNA → Protein
(Change) (Change) (Change)
•Same/Silent Mutation:
DNA → RNA → Protein
(Change) (Change) (No Change)
•Non-Sense Mutation:
DNA → RNA → Protein
(Change) (Change) ( Stop)

7. •Missense Mutation:
Change in nucleotide sequence brings
different types of protein.
•Same/Silent Mutation:
Change in nucleotide sequence brings no
change in protein type. It is due to
degeneracy of genetic.
•Non-Sense Mutation:
Change in nucleotide sequence brings
non-sense codon (UAA, UAG, UGA) at a
new position in the mRNA as a result, protein
synthesis adversely stops.

8. 2. Base Substitution
•Replacement of one base pair by
another pair in the DNA is known as
base substitution.
i) Transition:
Purine Purine Purine Purine
→ or →
→ or →
Pyrimidine Pyrimidine Pyrimidine Pyrimidine
A
C
G
T
G A
C
T

9. •ii) Transversion:
Purine Pyrimidine Pyrimidine Purine
→ or →
→ or →
Pyrimidine Purine Purine Pyrimidine
A
T
T
C
G
G
C
A

10. 3. Insertion
•Insertions are mutations in which
extra base pairs are inserted into a
new place in the DNA.

11. 4. Deletion
•Deletions are mutations in which a
section of DNA is lost, or deleted.

12. •If it occurs in coding sequences and
involves one, two or more
nucleotides which are not a multiple
of three, it will disrupt the reading
frame.

13. 5. Frameshift Mutation
• Mutation caused by the addition or deletion of a
base pair or base pairs in the DNA of a gene
resulting in the translation of the genetic code in
an unnatural reading frame from the position of
the mutation to the end of the gene