Transgênicos (Biotecnologia) - Aula 21 - Módulo II: Genética | Prof. Gui

Understanding Transgenic Organisms

Introduction to Transgenics

• The speaker, Guilherme, introduces the topic of transgenic organisms and their implications for human health.

• A genetically modified organism (GMO) is defined as one whose genetic material has been artificially altered. This includes organisms from which DNA has been removed or to which foreign DNA has been added.

Key Concepts in Genetic Modification

• Transgenic organisms carry genes from other species; for example, inserting bacterial DNA into a plant creates a transgenic plant.

• Not all genetically modified organisms are considered transgenic. For instance, removing a cancer-causing gene from an organism does not classify it as transgenic since no foreign gene is introduced.

Mechanisms of Genetic Engineering

• Bacteria contain plasmids—small circular DNA molecules that serve as vectors in genetic engineering by transporting desired genes into other cells.

• Plasmids are effective because they have minimal genes and can direct cellular machinery on how to read the inserted genetic information.

Identifying Genes of Interest

• To find useful genes, various bacterial strains are exposed to herbicides until a resistant strain is identified. This strain likely contains a gene conferring resistance.

• Once the resistant bacterium is found, scientists isolate its genes to determine which specific gene provides herbicide resistance.

Gene Insertion Techniques

• Restriction enzymes act like biological scissors that cut DNA at specific sites, allowing scientists to isolate and insert desired genes into plasmids.

• After cutting both the target gene and plasmid with restriction enzymes, ligase enzymes are used to join them together, creating a recombinant plasmid containing the gene of interest.

Creating Transgenic Plants

• The newly formed plasmid with the transgene is introduced into plant cells. These cells then become transgenic once they incorporate the new genetic material.

• Using plant hormones like cytokinins promotes cell division and growth in vitro, leading to the development of whole plants from these modified cells.

Conclusion: From Cells to Plants

• The process culminates in producing small clusters of cells that differentiate into roots and shoots, ultimately forming new transgenic plants ready for further study or cultivation.

Understanding Recombinant DNA and Transgenic Cells

Origin of Transgenic Cells

• All cells originate from a single cell through mitotic processes, carrying the transgene, which is recombinant DNA.

• Recombinant DNA refers to artificially separated and recombined DNA, crucial for genetic engineering.

Techniques in Genetic Engineering

• The process may involve multiple genes being inserted into a cell to increase the chances of successful procedures.

• Large-scale multiplication of genes and plasmids occurs in laboratories, utilizing techniques like PCR (Polymerase Chain Reaction).

Importance of Community Support

• The speaker encourages viewers to support the project by subscribing, liking, and sharing the video to spread awareness about transgenic topics.