1

Immagini e concetti della biologia Sylvia S. Mader Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

B5 - Biotechnology and genomics Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Restriction enzymes Enzymes that cleave and repair DNA are used to manipulate and recombine DNA. Restriction enzymes, naturally used by bacteria as defense against bacteriophages, cut DNA into smaller pieces. Restriction enzymes cut DNA at specific base sequences called restriction site. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Recombinant DNA DNA fragments can be rejoined, by DNA ligase in bacterial plasmids, to form a new molecule of recombinant DNA (rDNA). Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Recombinant DNA rDNA can be used either to clone genes or to make a specific protein. Bacteria takes the recombinant plasmid Gene cloning Protein production The altered host cell is called transgenic or genetically modified organism (GMO). Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

PCR Using the Polymerase Chain Reaction (PCR) it is possible to obtain copies of a specific sequence of DNA. PCR uses: DNA-polymerase, an enzyme that makes copies of the DNA strand; Free Nucleotides, to create the new strand. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

PCR PCR is the basis for many important DNA analysis as DNA fingerprint and evolutionary studies. PCR-base DNA fingerprint use to determine paternity. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Animal cloning Animals can be cloned using a donor diploid nucleus. The aim of a reproductive cloning is to obtain a new organism, genetically identical to the original. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Animal cloning Desire of a therapeutic cloning is to obtain mature cells of various types for medical purposes. Either embryonic stem cells or adult stem cells may be used in therapeutic cloning. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Animal cloning Benefits Reproductive cloning can help save endangered species. Therapeutic cloning can provide valuable medical products and fight cancer. Drawbacks Donor mitochondrial DNA is not transmitted and the clone may undergo premature aging. In clones, mutation rate is higher and anomalies in gene regulation occur. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Genetically Modified Organisms Recombinant DNA technologies produce genetically modified bacteria to manufacture medical and commercial products (as insulin) and perform specific services (as water treatment). Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Genetically modified plants Future objective for genetically modified crops Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Genetically modified plants Genetic engineering is also used to increase plant resistance to harsh environments (drought, frost, acid, salt). Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Genetically modified plants Genetically modified plants, as Solanum tuberosum, are also developed to improve pest resistance to the potato bug (Leptinotarsa decemlineata). Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Are GM foods safe? Countries have different regulations for GMO and the derived food commerce and cultivation. Long-term problems related to GMO could be: Environmental risks Ecological impact Health and allergies risks Impact on biodiversity Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Genetically modified animals Animals are genetically engineered to exalt specific traits or obtain useful products: GM animals can produce pharmaceuticals GM mice are bred for human disease research Xenotransplantation (animals as organs donor in transplantation) Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Genetically modified animals Genetically engineered animals are often used to obtain female mammal clones able to produce a specific product as the human growth hormone. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Human Genome Project Human genome has been sequenced in “Human Genome Project” (HGP). The order of about 3x109 bases contained in the human DNA has been determined. Genome sizes of humans and other sequenced species Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Human gene therapy Gene therapy is used to modify abnormal genes and can be done in two ways. ex vivo - anomalous cells are removed, treated and reinserted into the body. in vivo - the gene is delivered directly into the body. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Future genetics Because of the HGP, new and safer medicines will be available and genetic disorders may be corrected. Based on the genetic profile of a single person, personalized therapies will be more available. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Proteomics and bioinformatics Proteomics is the study of the structure, function and interaction of cell proteins. The human proteome is the complete collection of proteins that humans synthesize. Bioinformatics is the application of computer technologies to the study of the genome. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

Functional and comparative genomics One aim of functional genomics is to discover how genes work in order to produce differentiated cells and tissues. Comparative genomics focuses on determining how species are related and the function of genes and noncoding regions. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018