Differences Between Viroids and Prions
In this article we will discuss about Differences Between Viroids and Prions.
Viroid:
Viroids are known as the smallest infectious pathogens which are made up solely of a short strand of circular, single-stranded self-replicating RNA that has no protein coating.
Prions:
Prion is an abnormal or misfolded protein that causes fatal disease in animals and humans by transmitting their misfolded shape onto normal variants of the same protein.
Differences Between Viroids and Prions
| Topic | Viroids | Prions |
| Nature | It is an infectious RNA particle | It is an infectious protein particle. |
| Composition | It is composed of only small single stranded circular RNA. | It is only composed of Protein. |
| Nucleic acid | Present | Absent |
| Protein coat | Absent | Not known |
| Inactivation | Viroids are inactivated by ribonuclease digestion. | Prions are inactivated by proteinase K and trypsin digestion. |
| Resistant | Resistant to proteinase K and trypsin digestion | Resistant to ribonuclease treatment. |
| Size | Viroids are smaller than virus | Smaller than viroids. |
| Host | Viroid infects only higher plants (Exception: hepatitis D virus in humans is similar to viroid) | Prions infect animals causing neurological degenerative diseases |
| Disease Name | Common plant diseases include Potato Spindle tuber disease, Chrysanthemum stunt disease. | ‘Mad cow disease’ (Bovine spongiform encephalopathy) in cow and Scrapie disease in sheep and goat, Creutzfeldt-Jakob Disease (CJD), Kuru, and Gerstmann-Strausler-Sheinker syndrome in humans. |
