Genetic RNA:

 

Introduction:

 

Those RNAs that have the ability to replicate, mutate, undergo recombination and perform protein synthesis using its encoded information; virtually behaving like a DNA are called Genetic RNAs.  Most of the genetic RNAs are found in viruses, viroids and virusoids.

 

A list of few RNA Viruses, Viroids and Virusoids:

 

 

Virus

Shape

Nature

Size and number of genome

Single stranded; +/- sense

TMV (Tobacco mosaic virus)

Rod

Naked

Single, 6395 ntds

Single stranded, (+) sense

RSV (Rous sarcoma Virus)

Isometric

Enveloped

2n, 8000 ntds

Single stranded, (+) sense

Picorna virus

Isometric

Naked

Single, 7433 ntds

Single stranded, (+) sense

Rhabdo virus

Bullet

Enveloped

Single, 11,000 ntds

Single stranded, (-) sense

Influenza virus

Spherical

Enveloped

Eight, size vary

All single stranded, (-) sense

Reo Virus

Isometric

Naked

Ten, size vary

All double stranded, (+/_) sense

MS2, Qbeta, phages

Isometric

Naked

4400 ntds, One,

Single stranded, (+) sense

HTLV-I and II

Isometric

Enveloped

Two, ~8.2 Kb each

Single stranded, (+) sense

HIV-I and II

Isometric

Enveloped

Two, ~8  to 9 kb

Single stranded, (+) sense

Viroids

 

 

 

 

Virusoids

 

 

 

 

 

 

 

General Features:

 

 

 

 

 

 

 

 

 

 

 

 

Those RNAs, that have the ability to replicate, mutate, undergo recombination and perform protein synthesis using its encoded information; virtually behaving like a DNA, are called Genetic RNAs.  Most of the genetic RNAs are found in viruses, viroids and virusoids. No such RNAs are observed or detected in plants or animals

 

RNAs, those, endowed with all potentialities to replicate, mutate, recombine and perform function, are called genetic RNAs, for they act and behave like any DNAs that act as genetic materials.  Almost all genetic RNA are found in few classes of viruses and viroids and virusoids.