Mutagenesis power point presentation.pptx

Mutagenesis

1. MUTAGENESIS Dr. Bukenya Ali

2. Introduction Types of mutagenesis Application of mutagenesis. Contents..... . 2

3. MUTAGENESIS Mutagenesis  :- is a process by which the genetic information of an  organism is changed, resulting in a  mutation . It may occur spontaneously in nature, or as a result of exposure to  mutagens. It can also be achieved experimentally using laboratory procedures. In nature mutagenesis can lead to cancer and various  heritable diseases, but it is also a driving force of evolution.

4. Types of mutagenesis Directed mutagenesis Site-directed mutagenesis PCR mutagenesis Insertional mutagenesis Signature tagged mutagenesis Transposon mutagenesis Sequence saturation mutagenesis

5. Directed mutagenesis Directed mutagenesis , also known as  directed mutation , was a hypothesis proposing that organisms can respond to environmental stresses by orthogenetically directing mutations to certain genes or areas of the genome. Different types of directed mutagenesis are a ) oligonucleotide directed mutagenesis with M13 DNA b) oligonucleotide directed mutagenesis with plasmid DNA c) PCR Amplified oligonucleotide directed mutagenesis. advantages :- Mutation rates is high All mutations can be induced Systematic and detailed Investigation of the targeted mutation can be made

6. Site-directed mutagenesis Site-directed mutagenesis  is a molecular biology method that is used to make specific and intentional changes to the DNA sequence of a gene and any gene products. Also called  site-specific mutagenesis  or  oligonucleotide -directed mutagenesis , it is used for investigating the structure and biological activity of DNA, RNA, and protein molecules, and for protein engineering

7. Conti… In molecular biology, insertional mutagenesis is the creation of mutations of DNA by the addition of one or more base pairs. Such insertional mutations can occur naturally, mediated by viruses or transposons , or can be artificially created for research purposes in the lag. Signature-tagged mutagenesis  ( STM ) is a genetic technique used to study gene function. Recent advances in genome sequencing have allowed us to catalogue a large variety of organisms' genomes, but the function of the genes they contain is still largely unknown. Using STM, the function of the product of a particular gene can be inferred by disabling it and observing the effect on the organism. The original and most common use of STM is to discover which genes in a pathogen are involved in virulence in its host, to aid the development of new medical therapies/drugs.

8. Transposon mutagenesis Transposon mutagenesis , or  transposition mutagenesis , is a biological process that allows genes to be transferred to a host organism's chromosome, interrupting or modifying the function of an extant gene on the chromosome and causing mutation.

9. APPLICATION Site directed mutagenesis is used to study changes in protein activity that occurs as a result of the DNA manipulation. It is used to assess the activity of proteins containing known amino acid substitutions. It is used to select or screen for mutations (at the DNA, RNA or protein level) that have a desired property; and which can be manipulated further for enhance biological activity. It is used to change specific amino acid in an enzyme. In this case, the modified enzyme molecule is assayed and compared to the wild-type enzyme molecule. It is used to introduce or remove restriction endonuclease sites or tags. Site-directed mutagenesis helps scientists to study the mechanism of action behind biological reactions catalyzed by enzymes  in vivo .

10. APPLICATION Recombinant DNA technology and the use of synthetic DNA molecules make it possible for molecular biology scientists to induce specific mutations in specific genes.   In vitro  mutagenesis is used to purposefully change genetic information. The analysis of the subsequent changes in gene expression and gene products helps elucidate the functional effect of the mutation. There are various types of mutagenesis. Site-directed mutagenesis, cassette mutagenesis and random mutagenesis are some examples of mutagenesis. It is noteworthy that the particular mutagenesis method you choose to use will depend on the goal of the project and the information you have about the target gene sequence to be altered