Mutation (General microbiology and Life sciencs)

This presentation delves into the intricate world of mutations, exploring their biological significance, mechanisms, and implications across different organisms. Beginning with an overview of genetic mutations and their types—ranging from point mutations to chromosomal aberrations—it discusses the causes of mutations including environmental factors and DNA replication errors. Special emphasis is placed on the role of mutations in evolution, disease development, and genetic diversity. Additionally, the presentation highlights current research trends and technologies used in mutation analysis, providing insights into future directions in genetic research and potential therapeutic applications.

1. Mutation Presented by : Chirantan Sandip Saigaonkar Reg. no.: FTS/2020/41 Shramshakti College of Food Technology, Maldad

2. What Are Mutations? Changes in the nucleotide sequence of DNA May occur in somatic cells (aren’t passed to offspring) May occur in gametes (eggs & sperm) and be passed to offspring The term “mutation” was coined by Hugo de Vries , which is derived from Latin word meaning “to change” A mutation is a permanent alteration in the sequence of nitrogenous bases of a DNA molecule. Mutations can be spontaneous, or induced by a mutagen in the environment. The process of mutation is called mutagenesis and the agent inducing mutations is called mutagen .

3. Types of mutation

4. Mutagen

5. Types of mutation

6. Chromosomal mutation Changing the structure of a chromosome The loss or gain of part of a chromosome

7. Chromosome Mutation Animation

8. Deletion Due to breakage A piece of a chromosome is lost Inversion Chromosome segment breaks off Segment flips around backwards Segment reattaches

9. Duplication Occurs when a gene sequence is repeated Translocation Involves two non homologous chromosomes Part of one chromosome is transferred to another.

10. Nondisjunction Failure of chromosomes to separate during meiosis Causes gamete to have too many or too few chromosomes Disorders: Down Syndrome – three 21 st chromosomes Turner Syndrome – single X chromosome Klinefelter’s Syndrome – XXY chromosomes

11. Gene Mutations Change in the nucleotide sequence of a gene May only involve a single nucleotide May be due to copying errors, chemicals, viruses, etc.

12. Point Mutation Change of a single nucleotide Includes the deletion, insertion, or substitution of ONE nucleotide in a gene Sickle Cell disease is the result of one nucleotide substitution Occurs in the hemoglobin gene

13. Frameshift Mutation Inserting or deleting one or more nucleotides Changes the “reading frame” like changing a sentence Proteins built incorrectly

14. Substitution Mutation A  substitution  is a  mutation  that exchanges one base for another (i.e., a change in a single "chemical letter" such as switching an A to a G)

15. Insertion Mutation The addition of one or more nucleotide base pairs into a DNA sequence

16. Deletion Mutation A part of a chromosome or a sequence of DNA is lost during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome

17. Are Mutations Helpful or Harmful? Mutations happen regularly Almost all mutations are neutral Chemicals & UV radiation cause mutations Many mutations are repaired by enzymes Some type of skin cancers and leukemia result from somatic mutations Some mutations may improve an organism’s survival (beneficial)

18. Mutation repair Most cells possess four different categories of DNA repair system : Direct repair systems , as the name suggests, act directly on damaged nucleotides, converting each one back to its original structure. Excision repair involves excision of a segment of the polynucleotide containing a damaged site, followed by resynthesis of the correct nucleotide sequence by a DNA polymerase . Mismatch repair  corrects errors of replication, again by excising a stretch of single-stranded DNA containing the offending nucleotide and then repairing the resulting gap. Recombination repair is used to mend double-strand breaks. Inducible or SOS repair is process by which E. coli repairs large amount of DNA damage.

19. References https:// qr.ae/pGlhPF https:// en.wikipedia.org/wiki/Mutation Microbiology . Pelczar , Chan and Krieg.