Lesson 2 – Recombinant DNA (Inquiry into Life pg. 500-507) Cell Biology: DNA Lesson 2 – Recombinant DNA (Inquiry into Life pg. 500-507)

Describe Recombinant DNA, including: Today’s Objectives Describe Recombinant DNA, including: Define recombinant DNA Describe a minimum of 3 uses for recombinant DNA

Recombinant DNA Definition: DNA having genes from 2 different organisms, often produced in the laboratory by introducing foreign genes into a bacterial plasmid A vector is used to introduce recombinant DNA into a cell A plasmid is the most common vector They are small rings of DNA found in bacteria The plasmid has to be removed from the bacteria and has to have a foreign gene inserted into it

Insertion of Foreign Genes An enzyme (restriction enzyme) breaks the plasmid DNA ring The new foreign DNA can now be attached to the plasmid The enzyme ligase acts like glue which sticks the foreign DNA to the plasmid and recreates the ring

Insertion of Foreign Genes

Recombinant DNA The plasmid DNA is then put back into the bacteria This bacteria will now replicate every cell the same as the one just put in Eventually there are many copies of the foreign gene

Applications of Recombinant DNA Recombinant human insulin Human insulin gene inserted into bacteria E. Coli, used to treat diabetes Recombinant human growth hormone (HGH) Treats patients with pituitary gland deficiencies to support normal growth and development Inserted into livestock to produce larger specimens Recombinant blood clotting factor VIII Blood clotting protein administered to patients with bleeding disorders Recombinant hepatitis B vaccine Control of hepatitis B virus Diagnosis of HIV infection Methods for diagnosing HIV have been developed using recombinant DNA Herbicide and Insect resistant crops Used in agriculture to reproduce genes that help crops resist attack by insects and protect crops from herbicides

Applications of Recombinant DNA Generate DNA libraries which will catalogue all the base sequences of known genes Identify specific genes In 1998, the gene that mutates to cause prostate cancer was identified Produce synthetic copies of genes Insert genetic material into chromosomes that will help regulate cell function to make organisms genetically “better”

Viral DNA Viral DNA (DNA from a virus) can also be used as a vector to carry recombinant DNA into a cell When a virus containing recombinant DNA infects a cell, the viral DNA enters Here it can direct the reproduction of many more viruses Each virus derived from a viral vector contains a copy of the foreign gene, therefore viral vectors allow cloning of a particular gene

Viral Vectors Viral vectors are also used to create genomic libraries A genomic library, or gene bank, is a collection of engineered viruses that carry all the genes of a species Purpose: Break up DNA into manageable chunks for research Can analyze specific strands of DNA/amino acid sequences to determine their function, which can then be inserted into other cells Stores all of the DNA for a species It takes about 10 million viruses to carry all the genes of a mouse

Summary Segments of DNA (particular genes) can be inserted into bacteria and the bacteria will produce these genes If desired genes are used – like those that produce certain chemicals (vaccines, antibodies, etc.) then these proteins become much more available Protein hormones like insulin (regulates blood-sugar levels) can be made using yeast cells Interferon, a protein used in cancer treatments to help the immune system is now mass-produced in this way

Antibiotic Resistance More and more bacteria are becoming resistant to our common antibiotics, and to make matters worse, more and more are becoming resistant to all known antibiotics The problem is known as multi-resistance, and is generally described as one of the most significant future threats to public health Antibiotic resistance can arise in bacteria in our environment and in our bodies Antibiotic resistance can then be transferred to the bacteria that cause human diseases, even if the bacteria are not related to each other

Antibiotic Resistance Antibiotic resistance-carrying plasmids from different bacteria can meet and exchange genetic material The result is plasmids consisting of genes that have each been adapted to different bacterial species

Antibiotic Resistance This facilitates further adaptation and mobility, and consequently the spread of antibiotic resistance between different bacterial species

Antibiotic Resistance Widespread abuse of antibiotics, particularly in agriculture, is rapidly increasing the proliferation of multi-resistant bacteria

Antibiotic Resistance Left unchecked, multi-resistant bacteria represent one of the greatest future health concerns in the world and could see the return of previously controlled diseases that affected humans in the past…… WITHOUT THE ABILITY TO STOP THEM Currently, bacteria are developing multi-resistance faster than scientists can develop new antibiotics to control them

Are you scared yet?!