Genetic modification

[Persephone]

Hey everyone, I'm a new member. My teacher gave us some exercises, and theyre due tomorrow.
I'm stuck and can't seem to find the answer in the book.

In gene manupilation we transfer a gen (Bt-gene) from a bacteria to soyaplants and corn, consequently the plants produce a protein, cry9C or Bt-toxin, both poisonous to many insects. Explain how the cells can "read" the gene, and result in the producing of Cry9C by the soyaplants?

Thanks in advance!

[mith]

Protein translation, read up on it.

[canalon]

finding something on the universality/conservation of the genetic code between species/genera/orders could be interesting too...

[Darby]

There is an interesting question here that I don't know the answer to - just having a gene isn't the same as expressing it. How is a cell with a transplanted gene compelled to express it?

[blcr11]

I don't know what book you're using or what type of course this is supposed to be, but see if there isn't a section or discussion about heterologous gene expression somewhere.

Most of the mechanics of gene expression are the same whether in a bacterium or eucaryotic cell: DNA is transcribed into mRNA which is translated into protein on the ribosomes. To get a bacterial gene to express in a plant cell, though--unless you happen to be very lucky--you have to put the gene under the control of a promoter that is active in plant cells. And then you probably have to have some sort of selectable marker that is also under the control of a plant-active promoter.

[Persephone]

Thank you all , yes it turnes out all I have to do is write about protein synthesis.
I've two more questions, first:

There have been warnings against placing plants with this gene (Bt-gene), because scientists don't know what could happen to the ecosystem and the food chain. What problems can you think of, based on what you know about biology.

I listed the following points:

-Humans or animal farms that eat GM plants might be harmed by the bacterial DNA in it, or by the Bt toxin.
-Insects that are not pests could be killed. Maize pollen with the toxin is blown onto wild plants growing near the maize. Insects feeding on the wild plants are therefore affected even if they do no feed on the maize.
-Populations of wild plants might be changed.
Cross pollination will spread the Bt gene into some wild plants but not others. These plants would then produce the Bt toxin and have an advantage over other wild plants in the struggle for survival.

Anything else I should add?

Second Q:
Farmers in Scandinavia use insecticides against fungus on plants. Explain the harmful effects and benefits of insecticides.

This is my reply:

Effects:
-Less damage caused by the insects, therefor higher crop yields to help reduce food shortages.
-Less land needed for crop production, so some could become areas for wildlife conservation.

Benefits:
-Insecticides are expensive, and can be harmful to farmworkers and to wildlife.

(couldn't think of anything else, if any of you have something to add I'd be greatful)


Thanks

[canalon]

Second Q:
Farmers in Scandinavia use insecticides against fungus on plants. Explain the harmful effects and benefits of insecticides.

This is my reply:

Effects:
-Less damage caused by the insects, therefor higher crop yields to help reduce food shortages.
-Less land needed for crop production, so some could become areas for wildlife conservation.

Benefits:
-Insecticides are expensive, and can be harmful to farmworkers and to wildlife.

Your answer is not good, because they ask for "harmful effects" and "benefits", not effects and benefits. In fact what you listed as effects could be listed under the benfits section. So you have to think about the drawbacks of insecticide use. I guess that anything about organic crop would easily list quite a lot of those. Although that should be taken with a grain of salt...

[Persephone]

Thanks alot for the help.