Anyone know of any good biochem/genetics forums

paralysed

I'm in the process of going over my BSc's final yr project, with the view of getting my head around the issues that I never really understood! It's tricky, seeing as it was a year ago now, & because I'm not just going over the things that I already managed to conceptualise.

This was the one I used so far, but it didn't seem very good at all for getting responses. As is, it takes a while to articulate a question before posting, so I'd prefer the idea of getting some answers for my persistence and frustration.

As I always thought, it's only when you go through the theory & figure it out for yourself, that you realise how badly explained it was by the lecturers! No wonder (over the course of 4 years) lecturers find themselves constantly coming back to concepts like PCR and being met with a wall of silence from the class!

molecularbiology.forums.biotechniques.com

Thanks

josey_whale

Your issue is that biology can be broken down into a huge number of sub-subjects. Consequently, there are no real central forums. However, there are forums out there that target specific communities. For example, SEQanswers, is very good for people looking for information on next generation sequencing. Researchgate is another good resource - specifically aimed at researchers.

Without knowing what kind of information you are looking for, it is difficult to point you to a particular website(s). There are loads of websites out there that explain concepts - many of them owned by reagent/instrumentation companies. Google is your friend!

Maybe if you give us a some specifics about the types of information you are looking for, we could help more.

paralysed

josey_whale wrote: »

Your issue is that biology can be broken down into a huge number of sub-subjects. Consequently, there are no real central forums. However, there are forums out there that target specific communities. For example, SEQanswers, is very good for people looking for information on next generation sequencing. Researchgate is another good resource - specifically aimed at researchers.

Without knowing what kind of information you are looking for, it is difficult to point you to a particular website(s). There are loads of websites out there that explain concepts - many of them owned by reagent/instrumentation companies. Google is your friend!

Maybe if you give us a some specifics about the types of information you are looking for, we could help more.

Thanks Jose,

Actually I do remember seeing questions posted on research gate with answers. I should try that.

Here's one example of I've asked if you'd like to look:

http://molecularbiology.forums.biotechniques.com/viewtopic.php?f=8&t=44331

josey_whale

paralysed wrote: »

On a particular tomato GM strategy I came across, scientists aimed to reduce gene expression of a particular type of gene... belonging to the tomato. The idea here (which I'll assume you've heard) is to get the gene's mRNA transcribed twice, so that both mRNA strands will bind to each other.

For this I imagined a section od DNA, with an artificial promoter and terminator being inserted on the anti-sense strand (on the same part of the genome) to transcribe the extra mRNA. I would have then imagined two RNA inition complexes (from either end) travelling towards each other, resulting in two separate RNA strands that would bind to each other.

But the lecturer then went on to say that "the method involves inserting an exact same gene somewhere else on the genome, but turning it around. It'll therefore have promoter and terminator on wrong side." So how on Earth is that supposed to make the new RNA be complementary to the original gene's RNA? Also, when he said "turned around" did he mean that it'd be on the same strand?

So, this technique is called RNA interference (RNAi). It could also be described as gene silencing. There are many strategies used to accomplish RNAi. Google it!

I am unfamiliar with the technique that you describe. However.... here how this would work.

Gene A (hypothetical sequence below) is transcribed into what we will call mRNA+

5'-AGGCCCTTTTAAGGCA This is the sense strand
3'-TCCGGGAAAATTCCGT This is the negative sense

The above would be transcribed into

5'-AGGCCCUUUUAAGGCA. This is your mRNA+ (the mRNA you want to silence)

So what you would do is design a gene whereby the negative sense (3' sequence) strand is now the coding sequence (sense) - inserting the promoter and terminator accordingly - This is what your lecturer unconventionally referred to as turning the sequence around!

5'-TGCCTTAAAAGGGCCT
3'-ACGGAATTTTCCCGGA

The above is then transcribed into

5'-UGCCUUAAAAGGGCCU. Let's call this mRNA-

So taking your mRNA+ and mRNA- (remembering they will hybridize 5'-3')

5'-AGGCCCUUUUAAGGCA (mRNA+)
3'-UCCGGGAAAAUUCCGU (mRNA-)

Once hybridized, mRNA+ cannot be be translated (or at least is suppressed) - as a result of not being able to enter the ribosome or as a result of RNAse mediated degradation. Therefore the gene's expression is altered!

I hope the above makes sense!

JW

paralysed

josey_whale wrote: »

So, this technique is called RNA interference (RNAi). It could also be described as gene silencing. There are many strategies used to accomplish RNAi. Google it!

I am unfamiliar with the technique that you describe. However.... here how this would work.

Gene A (hypothetical sequence below) is transcribed into what we will call mRNA+

5'-AGGCCCTTTTAAGGCA This is the sense strand
3'-TCCGGGAAAATTCCGT This is the negative sense

The above would be transcribed into

5'-AGGCCCUUUUAAGGCA. This is your mRNA+ (the mRNA you want to silence)

So what you would do is design a gene whereby the negative sense (3' sequence) strand is now the coding sequence (sense) - inserting the promoter and terminator accordingly - This is what your lecturer unconventionally referred to as turning the sequence around!

5'-TGCCTTAAAAGGGCCT
3'-ACGGAATTTTCCCGGA

The above is then transcribed into

5'-UGCCUUAAAAGGGCCU. Let's call this mRNA-

So taking your mRNA+ and mRNA- (remembering they will hybridize 5'-3')

5'-AGGCCCUUUUAAGGCA (mRNA+)
3'-UCCGGGAAAAUUCCGU (mRNA-)

Once hybridized, mRNA+ cannot be be translated (or at least is suppressed) - as a result of not being able to enter the ribosome or as a result of RNAse mediated degradation. Therefore the gene's expression is altered!

I hope the above makes sense!

JW

That makes a lot of sense. Thank Josey.

I think I might have been thinking of the "gene" as only being one strand (as opposed to two), which might have led to my confusion.