Skip to main content
. 2020 Aug 1;21(15):5532. doi: 10.3390/ijms21155532

Table 1.

Developments in sequencing technologies and their impact on viroid research.

Year Milestones
Sequencing Technology Viroid Biology
1960s RNA fingerprinting -  Chemical characterization of the first viroid
1970s Detection of radiolabelled partial-digestion fragments by two-dimensional fractionation -  Sequencing of the first viroid RNA and secondary structure elucidation
1980s Sanger’s chain-termination technique
Maxam and Gilbert’s chemical degradation technique
  • -

    Determination of the structural/functional domains, central conserved region (CCR), and hammerhead self-cleavage

  • -

    Viroid classification

  • -

    Viroid isolates
1990s–to date Automated sequencers
  • -

    Mutagenic studies

  • -

    Structure of viroids

  • -

    Quasi-species
2005–to date Next-generation sequencers
  • -

    Characterization of viroid derived small RNAs (vd-sRNA)

  • -

    Quasi-species: Large scale mutation rates and population dynamics

  • -

    Effect of viroid infection host genome: Transcriptome analysis and degradation studies