Recombinant DNA Technology

Chapter 15

In the 1950s, the basic structure of DNA had been revealed, however, no one could figure out how to reveal the order of the genes within the sequence.

Hamilton Smith accidentally discovered that Haemophilus influenza, a bacterium, could chop DNA.

It holds restriction enzymes that restrict activity to certain sites on the DNA.

In several years, hundreds of bacterial strains were found to hold these enzymes.

The enzymes recognize and can cut DNA into readable strands.

These strands help scientists study the genome, which is the entire DNA in a haploid number for each species.

For the human, it is about 3.2 billion base pairs long.

No two people have the same sequence of DNA (except identical twins).

Each human has a unique DNA fingerprint, which can be used to identify that person from any other.

They are unique arrays of DNA patterns that were inherited from each parent.

These patterns are so accurate that they can be used for paternity tests and to determine one sibling from another.

A test called gel electrophoresis is used to sequence the DNA.

It uses an electric field to move molecules through a gel.

Possible Uses

1. Identify suspects from DNA evidence2. Identify victims who do not have

identification

Laboratory mice were the first mammals used in genetic experiments. Human genes are being inserted into mouse embryos to study several disorders. Some of these disorders include: Alzheimer’s and Dwarfism.

In 1997, the first case of cloning was reported.

They took the nucleus of an ewe’s mammary cell and inserted it into the egg of a different ewe.

The embryo was implanted and the offspring named Dolly resulted.

Two reasons an adult clone has advantages:1. An adult already displays the

trait that is sought2. Cloning might maintain its

genotype infidelity

The first clone gave rise to the possibility of cloning other barnyard animals, and the fear that eventually human cloning is on the way.

The United States government has placed a ban on cloning of humans.

Researchers are, however, looking at ways to insert human genes into animal cells to cure or treat disease.Using cow cells to produce human

albumin (which is used to treat high blood pressure)

Since 1990, the Human Genome Initiative (Project) has been an ongoing process to map out the entire sequence of DNA in the human being.

Benefits

1) Cure genetic disorders2) Combat diseases