When do mutations occur?

[o4aclaireism]

I teach a higher level biology class and I'm thinking about having them come up with the mutations behind some of the wilder TV/cartoon characters.

When can mutations happen? I know they happen during Meiosis and mitosis and replication. I'm assuming they can also happen during transcription and translation; is this correct? I also know about environmental causes.

Can anyone tell me about mutations that occur during transcription and translation? What enzyme is to blame? Perhaps it's the ribosome.

Any input would be great!
Claire H

[mith]

what exactly is a higher level bio class, and why are you teaching it? It seems you don't have the biology background...

[o4aclaireism]

I teach a biotechnology class at a high school. My background is more along the lines of PCR and FISH, just not mutations.

CH

[jonmoulton]

A mutation is a change in the DNA. Errors in transcription and translation do occur, but these cause errors in RNA or protein respectively. I would not consider this sort of change a mutation.

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Mutation 1. the process by which a gene undergoes a structural change. 2. a modified gene resulting from mutation. 3. by extension, the individual manifesting the mutation.

From: A Dictionary of Genetics 7th Ed. King RC, Stansfield WD, and Mulligan PK. 2006. Oxford University Press, New York NY.
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I agree that in the absence of external insult, such structural changes in DNA are most likely to occur during meiosis, mitosis, and replication. Exposure to physical or chemical insults from the environment (e.g. short-wave UV irradiation, exposure to intercalating mutagens, etc.) and some biological insults, such as infection by papillomavirus, may either independently cause mutations or increase the probability that mutations will occur during meiosis, mitosis, or replication.

My favorite mutation is the zebrafish mutant, one-eyed pinhead (oep). See slide 62 in this presentation:
http://www.gene-tools.com/files/Philomath2008.ppt

Regards,

- Jon

[Darwin420]

HAHaha, Mith you are an ass!! Hahhaa. Yes mutations can occur during translation. Think about UV radiation which can cause lesions in DNA which block the RNA polymerase thus, no transcription which means absence in protein or complete loss of function in a cell. This is a mutation. So yes it can occur during translation.

[Darwin420]

Sorry, I meant transcription

[mith]

It seems strange, most instructors don't come asking for technical information, most look for creative ways to express scientific principles in interesting modes.

[MichaelXY]

Sounds like a very creative approach by a student needing an answer. With such creativity, maybe an art class would be more suitable.

[MrMistery]

This person is either a lab technician trying to be a biologist(a really bad lab technician), or, as Micheal said, a creative student. No biologist on this planet would learn to do PCR and FISH without first learning the fundamentals of DNA replication and mutation.

[jonmoulton]

"Yes mutations can occur during translation. Think about UV radiation which can cause lesions in DNA which block the RNA polymerase thus, no transcription which means absence in protein or complete loss of function in a cell. This is a mutation. So yes it can occur during translation."

Doesn't the mutation occur when the UV photon hits the bases and causes a rearrangement of covalent bonds (e.g. thimine dimerization)? The effect on transcription comes later, after the UV interaction, when the polymerase encounters the modified bases; at that point the change in the DNA has already occurred.

[Darwin420]

jonmoulton - yea yea you are correct. It is the UV radiation that causes the mutation BUT it is the lesions that disable the polymerase to continue transcription. But yea, I should of been more careful about what I was saying.

[o4aclaireism]

I am ACTUALLY a teacher.

I just wanted to know a little bit of information, that I didn't know. Amazingly enough teachers do not know everything, we do know when to ask questions to people who are hopefully smarter than ourselves. I am not a biogist and I never said I was one. DId I? I know and understand the basics of mutations (point mutations, insertions, frammeshifts etc); I meant to ask a more specific question. I wanted to know about the problems that can happen during transcription and translation and if they can be called a mutation.

I have not gone into the details about why I want this information. Frankly, I didn't think you would be that interested. It will be used in a creative way in my classroom.

I do think it is interesting that I got different answers from several of you. My question (which you seem to think is stupid) is whether or not a mutation can occur when working with RNA. Does this words just apply to DNA? Apparently you disagree.

I am sorry that I stepped into the a-holes department.
I just wanted a little bit of DETAILED information that I lack. I do indeed know all about the central dogma etc. Why do you have to make someone feel stupid when all I asked was a simple question?

I will never trouble you again with my stupid questions.

CH