RNA as genetic material

[Lumi]

DNA has taken over RNA as genetic material during evolution majorly due to its structural stability....my question is why some viruses still have RNA as the genetic material? Why they take the extra burden of genes coding for Reverse transcriptase when they can have DNA directly as the genetic material which can be incorporated into the host genome?

[MrMistery]

What don't bacteria suddently all develop a nucleus and organelles so their methabolism will be better? becuase they are primitive. Same thing with RNA viruses. They are primitive, the fact they have RNA as genetic material is one of the characteristics of their state.

[victor]

Yup..as Andrew (Mr.Mistery) said, there're 3 types of viruses gruped based on their genetic substances. It's already their speciality to be known as RNA viruses or DNA viruses.
PS: if you feel uncomfortable with this fact, just complain to the RNA viruses and.....please send them a regards from me..

[Daniel Tillett]

An RNA genome can be an advantage as it can speed up the process of getting your genes translated into proteins. By having an RNA genome these viruses can avoid the initial DNA to RNA transcription step.

Daniel

Improved automated DNA sequencing

[Dr.Stein]

It should be understood that some organism does not evolve, thus they still keep in primitive level but they are survive with the primitiveness (---> is it the correct term? ), while another organism evolves to be an advance one.

[Jelanen]

Also, having RNA as the mode of information transportation allows for mutations to have a quicker effect (or detriment) so that the virus can avoid those pesky antivirals.

-Jelanen

oh, btw...check out http://www.thinkgeek.com/cubegoodies/toys/6708/ if you are a true bacteria/virus nerd (I have adenovirus and H. pylori)

[rambobala]

hi friend,
viruses got still their genetic material as rna since
1.human evolved from monkeys but still monkeys are here in this world
2.likewise dna is from rna but both are here coexixting
3.rna viruses are having still rna because they are like monkeys living among humans
4.they dont carry RT inborn they picked it from some other organism during evolution(of course viruses are co evolved)

[protozoan]

Or natural selection still doesnt delete them from the face of the earth. They re still succesfull so many years.

[lockers]

Many viruses make use of an RNA genome because it allows variation, mainly due to its primitive system of replication. unlike DNA genomes which have something called a 'proof reading' system which allows exonuclease activity, things like viruses dont, which means mistakes happen alot more frequently and are not corrected. this is why we cannot get vaccinated against the common cold, because its an RNA beased virus which is constantly changing its genetic make-up, making it unrecogniable to antibodies. hope this helps.

[bellyjelly]

RNA and DNA are both nucleic acids, but differ in three main ways. First, unlike DNA, which is, in general, double-stranded, RNA is a single-stranded molecule in many of its biological roles and has a much shorter chain of nucleotides. Second, while DNA contains deoxyribose, RNA contains ribose (in deoxyribose there is no hydroxyl group attached to the pentose ring in the 2' position). These hydroxyl groups make RNA less stable than DNA because it is more prone to hydrolysis. Third, the complementary base to adenine is not thymine, as it is in DNA, but rather uracil, which is an unmethylated form of thymine.

Like DNA, most biologically active RNAs, including mRNA, tRNA, rRNA, snRNAs, and other non-coding RNAs, contain self-complementary sequences that allow parts of the RNA to fold and pair with itself to form double helices. Analysis of these RNAs has revealed that they are highly structured. Unlike DNA, their structures do not consist of long double helices but rather collections of short helices packed together into structures akin to proteins. In this fashion, RNAs can achieve chemical catalysis, like enzymes. For instance, determination of the structure of the ribosome—an enzyme that catalyzes peptide bond formation—revealed that its active site is composed entirely of RNA.[