Genetic Engineering

Chapter 13-3

Standard 5c

5c: Students know how genetic engineering (biotechnology) is used to produce novel biomedical and agricultural products.

Genetic Engineering

Through recent technologies and really, really, ridiculously, really smart scientists, we now have techniques where we can control and change (to some extent) an organism’s DNA.

Genetic engineering: altering the structure of a DNA molecule by substituting genes from another DNA molecule

Genetic Engineering

So here’s the problem: I WANT TO EAT STRAWBERRIES ALL YEAR LONG!

But, strawberries can’t grow in the winter. The cold weather (ice & snow) prevents strawberries from growing.

Solution: I’ll take a gene from a cold-water fish and put it in a strawberry. Why?

Here’s the basic process…

DNA Recombination

DNA recombination is the process where a DNA fragment (gene) from an organism is inserted in a bacteria’s DNA. The bacteria replicates the DNA, causing mass production of the desired gene. Here are the steps…

1. You can’t just cut DNA anywhere (could cause damage), there are special DNA sequences called restriction sites where restriction enzymes cut the DNA into the desired fragment.

DNA recombination

2. Once you have cut genes, place the genes in specific bacterial DNA called plasmids.

3. Because of bacteria’s nature, the bacteria will replicate… A LOT!

4. The bacteria will turn the DNA into a protein.

5. Markers will be used to determine if the process was successful (glow, RA, etc…)

Example: Human growth hormone gene is transformed (put into) into a plasmid. Bacteria then mass produces HGH for human consumption.

DNA Recombination

Transgenic Plants

If you can take genes and put them in bacteria, why can’t you do that with plants?

WE ALREADY HAVE! Remember the strawberry problem? The bacterial DNA can be inserted in

embryonic plant cells. If they take up the DNA, they will produce the gene.

Other examples: Soil + corn = insect-resistant crops Tangerine + grapefruit = tangelo firefly + tobacco = glowing tobacco

Recombinant plasmid

Gene to be transferred

Agrobacterium tumefaciens

Cellular DNA

Transformed bacteria introduce plasmids into plant cells

Plant cell colonies

Complete plant is generated from transformed cell

Inside plant cell, Agrobacterium inserts part of its DNA into host cell chromosome

Section 13-3

Figure 13-10 Plant Cell Transformation

Plant Cell Transformation

Magic Tobacco Transgenic plants began in

1986 when a scientist named Steven Howell took a firefly’s luciferase gene (glowing) and inserted it in tobacco cells.

Where did Dr. Howell do his research?

Hint: it’s where all the good looking people go to college…

UCSD was named the “hottest” institution in the nation for students to study science by Newsweek and the 2006 Kaplan/Newsweek College Guide.

UCSD ranks 7th in the nation in National Academy of Sciences membership. (The top universities, in rank order, are: Harvard, Stanford, UC Berkeley, MIT, Princeton , Caltech, UCSD, Yale, Univ. of Wisconsin-Madison , Univ. of Chicago and Univ. of Washington.)

U.S. News and World Report ranks UCSD as 7th best public university in the nation, and 32nd among the nation’s top 50 universities.

UCSD was ranked the 4th best university in the nation by the Washington Monthly’s 2007 College Guide, based on the positive impact the university has had on the country.

The journal Foreign Policy ranked UCSD 9th in the nation for international relations studies and 10th for international public policy studies.

The National Research Council ranks UCSD 10th in the nation in the quality of its faculty and graduate programs. The NRC ranks oceanography and neurosciences 1st in the nation.

Transgenic animals

Growth hormone + trout = bigger fish Growth hormone + cattle = STEAK! AIDS virus + mouse = AIDS research