Download, print and study this document offline |
Page 1 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 1 NME-Zoology Subject: Genetics and Genomics Lesson: Uses of Transposons & Eukaryotic Viruses Lesson Developer: Dr. Shailly Anand 1 Dr. Jaya Malhotra 2 College/Dept: Deen Dayal Upadhyaya College 1 , Hansraj College 2 Page 2 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 1 NME-Zoology Subject: Genetics and Genomics Lesson: Uses of Transposons & Eukaryotic Viruses Lesson Developer: Dr. Shailly Anand 1 Dr. Jaya Malhotra 2 College/Dept: Deen Dayal Upadhyaya College 1 , Hansraj College 2 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 2 Table of Contents ? Uses of Transposons ? IS elements mediates recombination ? Formation of conjugative R plasmids ? Insertion mutations ? Chromosome breakage and rearrangement ? Genetic transformation ? Eukaryotic Viruses: An introduction ? Classification of Eukaryotic Viruses ? DNA & RNA viruses ? Icosahedral & Helical Viruses ? Naked & Enveloped Viruses ? Life Cycle of Eukaryotic Viruses ? Retroviruses: Special RNA Viruses ? Gene Composition ? Growth Cycle of Retroviruses ? Retroviruses & Oncogenes ? Summary ? Glossary ? Practice Questions ? Answer to the Questions ? References Page 3 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 1 NME-Zoology Subject: Genetics and Genomics Lesson: Uses of Transposons & Eukaryotic Viruses Lesson Developer: Dr. Shailly Anand 1 Dr. Jaya Malhotra 2 College/Dept: Deen Dayal Upadhyaya College 1 , Hansraj College 2 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 2 Table of Contents ? Uses of Transposons ? IS elements mediates recombination ? Formation of conjugative R plasmids ? Insertion mutations ? Chromosome breakage and rearrangement ? Genetic transformation ? Eukaryotic Viruses: An introduction ? Classification of Eukaryotic Viruses ? DNA & RNA viruses ? Icosahedral & Helical Viruses ? Naked & Enveloped Viruses ? Life Cycle of Eukaryotic Viruses ? Retroviruses: Special RNA Viruses ? Gene Composition ? Growth Cycle of Retroviruses ? Retroviruses & Oncogenes ? Summary ? Glossary ? Practice Questions ? Answer to the Questions ? References Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 3 Uses of Transposons For many years scientists could not answer the reason behind the presence of transposons in the genome. Without any significant contribution in the genome they should have been eliminated during the course of evolution. On the contrary, transposons are prevalent in almost all kinds of living organisms. They have served as nature’s genetic tool for manipulating and modifying the genomic organization of a particular genome. Some of the uses of transposons in the light of evolution have been listed below. IS elements mediates recombination Several copies of single type of IS elements can be present in a bacterial genome. These can be distributed in plasmid as well as the chromosome. When similar type of IS elements are present both in the plasmid and the chromosome they can undergo recombination to form a single bigger molecule by the integration of the plasmid in the chromosome. This Page 4 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 1 NME-Zoology Subject: Genetics and Genomics Lesson: Uses of Transposons & Eukaryotic Viruses Lesson Developer: Dr. Shailly Anand 1 Dr. Jaya Malhotra 2 College/Dept: Deen Dayal Upadhyaya College 1 , Hansraj College 2 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 2 Table of Contents ? Uses of Transposons ? IS elements mediates recombination ? Formation of conjugative R plasmids ? Insertion mutations ? Chromosome breakage and rearrangement ? Genetic transformation ? Eukaryotic Viruses: An introduction ? Classification of Eukaryotic Viruses ? DNA & RNA viruses ? Icosahedral & Helical Viruses ? Naked & Enveloped Viruses ? Life Cycle of Eukaryotic Viruses ? Retroviruses: Special RNA Viruses ? Gene Composition ? Growth Cycle of Retroviruses ? Retroviruses & Oncogenes ? Summary ? Glossary ? Practice Questions ? Answer to the Questions ? References Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 3 Uses of Transposons For many years scientists could not answer the reason behind the presence of transposons in the genome. Without any significant contribution in the genome they should have been eliminated during the course of evolution. On the contrary, transposons are prevalent in almost all kinds of living organisms. They have served as nature’s genetic tool for manipulating and modifying the genomic organization of a particular genome. Some of the uses of transposons in the light of evolution have been listed below. IS elements mediates recombination Several copies of single type of IS elements can be present in a bacterial genome. These can be distributed in plasmid as well as the chromosome. When similar type of IS elements are present both in the plasmid and the chromosome they can undergo recombination to form a single bigger molecule by the integration of the plasmid in the chromosome. This Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 4 Figure 1. Integration of F factor into the bacterial chromosome is mediated by transposon recombination. Source: Author (Malhotra, J.) bacterium becomes an Hfr bacterial strain and its genome can be transferred to other bacterial strains during conjugation. Hence the genes present on the plasmid can be transferred to other bacterial strains with the help of IS elements (Fig. 1). Formation of conjugative R plasmids Another important characteristic of the IS elements that are present on the plasmids is the formation of conjugative R plasmids from the non conjugative types (Fig. 2). The basic structure of a conjugative R plasmid has two components, one is the RTF (resistance transfer factor) that helps in transfer of the other component; R determinant. The R determinant contains genes that confer resistance to antibiotics or other antibacterial drugs; therefore such plasmids are termed as R plasmids. The RTF region of different plasmids bears similarity while the R determinant is more diverse in nature and can be flanked by IS elements. As already explained in the above paragraph the homologous IS elements can mediate transposition of the R determinant from one plasmid to another. Transposition can occur irrespective of their orientation. Page 5 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 1 NME-Zoology Subject: Genetics and Genomics Lesson: Uses of Transposons & Eukaryotic Viruses Lesson Developer: Dr. Shailly Anand 1 Dr. Jaya Malhotra 2 College/Dept: Deen Dayal Upadhyaya College 1 , Hansraj College 2 Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 2 Table of Contents ? Uses of Transposons ? IS elements mediates recombination ? Formation of conjugative R plasmids ? Insertion mutations ? Chromosome breakage and rearrangement ? Genetic transformation ? Eukaryotic Viruses: An introduction ? Classification of Eukaryotic Viruses ? DNA & RNA viruses ? Icosahedral & Helical Viruses ? Naked & Enveloped Viruses ? Life Cycle of Eukaryotic Viruses ? Retroviruses: Special RNA Viruses ? Gene Composition ? Growth Cycle of Retroviruses ? Retroviruses & Oncogenes ? Summary ? Glossary ? Practice Questions ? Answer to the Questions ? References Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 3 Uses of Transposons For many years scientists could not answer the reason behind the presence of transposons in the genome. Without any significant contribution in the genome they should have been eliminated during the course of evolution. On the contrary, transposons are prevalent in almost all kinds of living organisms. They have served as nature’s genetic tool for manipulating and modifying the genomic organization of a particular genome. Some of the uses of transposons in the light of evolution have been listed below. IS elements mediates recombination Several copies of single type of IS elements can be present in a bacterial genome. These can be distributed in plasmid as well as the chromosome. When similar type of IS elements are present both in the plasmid and the chromosome they can undergo recombination to form a single bigger molecule by the integration of the plasmid in the chromosome. This Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 4 Figure 1. Integration of F factor into the bacterial chromosome is mediated by transposon recombination. Source: Author (Malhotra, J.) bacterium becomes an Hfr bacterial strain and its genome can be transferred to other bacterial strains during conjugation. Hence the genes present on the plasmid can be transferred to other bacterial strains with the help of IS elements (Fig. 1). Formation of conjugative R plasmids Another important characteristic of the IS elements that are present on the plasmids is the formation of conjugative R plasmids from the non conjugative types (Fig. 2). The basic structure of a conjugative R plasmid has two components, one is the RTF (resistance transfer factor) that helps in transfer of the other component; R determinant. The R determinant contains genes that confer resistance to antibiotics or other antibacterial drugs; therefore such plasmids are termed as R plasmids. The RTF region of different plasmids bears similarity while the R determinant is more diverse in nature and can be flanked by IS elements. As already explained in the above paragraph the homologous IS elements can mediate transposition of the R determinant from one plasmid to another. Transposition can occur irrespective of their orientation. Uses of Transposable Elements & Eukaryotic Viruses Institute of Lifelong Learning, University of Delhi Page 5 Figure 2. A conjugative plasmid can be transformed into conjugative R plasmid by recombination with a non-conjugative R plasmid. Source: Author (Malhotra, J) This way of transfer of the resistance genes to other strains of bacteria have been a fast vehicle for evolution. It is of great concern in medical science as drug resistant bacterial strains are rapidly evolving and making the less virulent bacterial strains gain resistance. For instance, E. coli R plasmids have been transferred to different genera like Salmonella, Hemophilus to name a few. Because of the above reason, antibiotics should only be administered for serious bacterial infections and not for slight infections.Read More
1. What are transposons and how are they used in biotechnology engineering? |
2. How do transposons contribute to genetic diversity? |
3. What are the potential applications of transposons in biotechnology? |
4. How are eukaryotic viruses used in biotechnology engineering? |
5. What are the risks associated with the use of transposons and eukaryotic viruses in biotechnology engineering? |
|
Explore Courses for Biotechnology Engineering (BT) exam
|