gene extraction - (Apr/03/2006 )

Hi

Could someone please help me out with these questions?

1)Once the DNA has been extracted from an organism (i.e. a plant) why is it neccessary to use the polymerase chain reaction (PCR) before you can detect the gene on an electrophoresis gel?

2)Describe the pattern of DNA fragments on an electrophoresis gel that you would expect from plants without the Bt gene (wild type)?

3)Describe the pattern of DNA fragments on an electrophoresis gel that you would expect from plants which are hybird between wild type and MON810 plants?

Thanks alot
biology_06er

wow, LDYOH

So, in order for us to help you, we need to know where you have tried to look and what you think the answers might be?

Do you understand what is the nature of PCR?

Questions 2 and 3 need more background info before we can begin to answer them. What do you already know about the situation? What can you tell me about the Bt gene? I am assuming you are discussing transgenesis....and what do you know about cell line MON810?

We can help you figure out your answers, but we will not do the work for you.

Once the DNA has been extracted from an organism (i.e. a plant) why is it neccessary to use the polymerase chain reaction (PCR) before you can detect the gene on an electrophoresis gel?

PCR amplifies stuff.
If you only have one gene, you won't be able to see it on a gel. What you have to do, is make a lot of copies of it so you can see it.

no idea what a Bt gene is, and don't have the time to look it up at the moment.
Have you tried searching pubmed? they've got journal atricles etc that could be helpful.
try searching through "google scholar".

vetticus

Ps. don't get so testy with us, oh mere mortal you. give a little respect, get a little back. and don't yell, as you might sound a little angry and ingrateful.

Q2 &3 require you to tell us the primers you are using, the sizes of the products that you would expect, the number of primers etc, as well as the aim of the expt, so that we can determine what a result might be.

As well as that it helps if you suggest some answers to the questions you posed so that we can see if you are actually along the right track, otherwise people who are here precisely because they have done the work themselves, think you are just trying to freeload on our experience/knowledge. Also the questions you asked look exactly like the sort of questions I would expect for homework/lab report writeup which makes people suspicious.

Hello

Thank you for your comment vetticus3/bob1...first off I'd like to say sorryish, I did not have the intention of sounding ungrateful but was merely stating the fact that I asked for help not answers....2ndly-bob1, these was not homework/lab report questions but were questions we were advised to do before the real lab which had to do with gene extraction as it would be helpful...

So.....next time I post a question I will write what I think is a possible answer as to not look as though I am trying to "freeload" of your knowledge-as if!!!

biology_06er

p.s..as for the "give a little respect bit"...what did I say in my first post that looked disrespectful??? as my second post just related to what I said above

this is one of the funny correspondence i read... i understand the veterans here... they have a good point....

very good point.....

we are here to learn and confirm stuffs,we seek help to understand after our searching are futile... and therefore next time, dont make yourself too obvious by lifting the exact question from your manual or something...

i am a newbie myself and trust me, it pays to be respectful.....

ummm not to get sidetracked,

put you PCR your gene of interest because even in you digest the gene from the maize (I suspect it is maize as you are discussing the Bt gene) which can be tetraploid or more, you still only have approx 4 copies of the gene such a small amount of DNA will not bind a sufficient amount of EtBr to all visualisation, thus we PCR the gene of interest so that we can visualise it presence.

as for your second question, if you are just randomly digesting a wild-type maize genome, and want to compare that to a Bt maize genome, an agarose gel will not be able to give you such resolution, thus under random digestion both genomes would appear the same.

lastly as for hybridisation, this is a random procedure amonst plants, thus the resulting genome of the hybrid will vary from cross-pollination to cross-pollinaiton. that is the reason why plant breeders, cross plants then select those with the desired characteristic and use those plants to to back pollinate to remove the undesired traits that have accumulated.

your last 2 questions are rather vague, so I have tried to answer them as best as i can