Login

Join for Free!
112526 members


synonymous vs conservative missense mutation

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderator: BioTeam

synonymous vs conservative missense mutation

Postby hiro » Sat Aug 25, 2007 3:07 am

i don't know the differences between these 2 mutation... look the same to me...
and how do we know which mutation will be synonymous/ missense by looking at the change of codon?
User avatar
hiro
Garter
Garter
 
Posts: 47
Joined: Tue Apr 19, 2005 3:12 pm
Location: hk-->australia

Postby Katy_Bobbles » Sat Aug 25, 2007 4:50 pm

Hi hiro.

Synonymous (or silent) mutation is when there is substitution of 1 base for another. However this type causes no change in the resultant protein because the codon encodes the same amino acid

e.g. If CAU is changed to CAC it does not matter as both encode histidine.

Missense (or non-synonymous) mutations cause base substitution resulting in a codon which encodes a different amino acid

e.g. Sickle cell disease is caused by a GAG (which encodes glutamate) to GTG mutation resulting in the formation of valine instead. As a result Haemoglobin S is formed instead of the normal haemoglobin A/A2

Hope that makes sense :? :lol:
User avatar
Katy_Bobbles
Garter
Garter
 
Posts: 42
Joined: Tue May 22, 2007 4:23 pm
Location: Glasgow

Postby kotoreru » Sat Aug 25, 2007 10:47 pm

Good explanation, I like it :)
"What are humans if they don't learn at University? Animals, yes."

^^One of my ex-girlfriends said that. I stress the ex part.
User avatar
kotoreru
Coral
Coral
 
Posts: 400
Joined: Thu Apr 12, 2007 9:25 pm
Location: London


Postby Darby » Sat Sep 01, 2007 2:01 pm

Recent data suggest that silents may not be silent - codon changes, even from one to another that "on paper" produce the same amino acid, still change things like methylation sites and may have distinct effects on the expression rates of the alleles.

Isn't it fun when "basic knowledge" just won't sit still?
Darby
Viper
Viper
 
Posts: 1262
Joined: Thu Mar 02, 2006 5:29 pm
Location: New York, USA

Postby hiro » Wed Sep 12, 2007 5:02 pm

icic...more clear now thx~~
User avatar
hiro
Garter
Garter
 
Posts: 47
Joined: Tue Apr 19, 2005 3:12 pm
Location: hk-->australia

Postby MrMistery » Thu Sep 13, 2007 5:49 am

also note codon bias, which seems to be much more important that we originally thought
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)

Postby ramya » Mon Sep 24, 2007 6:29 am

hi hiro!
synonymous mutations are those that donot change the amino acid even if there is a substitution of one base in the place of other(degeneracy of genetic code) and it doesnt make any change in the protein structure or funtion or watever u say.but non-synonymous mutations change the aminoacid even with a single substitution of a base.jus like in sickle cell anaemia.
To know how far that non-synonymous mutation is harmful we have to check the percentage of conserveness of that particular sequence where v found that mutation.This would probably help the researchers to understand the affect of that particular mutation in the gene expression....
:D hope i didnot confuse u
ramya
Garter
Garter
 
Posts: 2
Joined: Mon Sep 24, 2007 5:57 am
Location: INDIA - Andhra Pradesh


Return to Genetics

Who is online

Users browsing this forum: No registered users and 2 guests

cron