TAG: GS 3: SCIENCE AND TECHNOLOGY
THE CONTEXT: A groundbreaking discovery at Stanford University has revealed the existence of microscopic entities named “obelisks” within the human mouth and gut.
EXPLANATION:
- These obelisks, described in a preprint study, exhibit unique characteristics, blurring the lines between viruses and viroids.
- As the scientific community delves into this intriguing world, a closer look is essential.
The Realm of Microscopic Entities
- Viruses and Viroids:
- Viruses, perched on the boundary of life, manipulate hosts for replication.
- Viroids, tiny RNA fragments, lack protective shells and protein-coding capabilities but can cause diseases in plants.
- Obelisks: A New Frontier:
- The term “obelisks” is coined for these entities due to their rod-like shape, self-organizing abilities, and circular single-stranded RNA genome.
- Positioned between viruses and viroids, obelisks possess genes predicting protein coding, distinguishing them from traditional viroids.
Key Characteristics of Obelisks
- Genetic Makeup:
- Obelisks feature a circular single-stranded RNA genome akin to viroids but lack a protein coat, resembling viruses.
- Their genomes encode proteins, with the major protein known as “obulin,” presenting an evolutionary mystery regarding its function.
- Abundance and Diversity:
- Analyses from human gut and mouth microbiomes reveal nearly 30,000 distinct obelisk types, challenging previous assumptions about their scarcity.
- Diverse niches globally house obelisks, with varying types in different body sites and donors.
- Host Relationships:
- Obelisks likely rely on microbial host cells, potentially bacteria or fungi, for replication.
- The specific hosts remain unidentified, but Streptococcus sanguinis in dental plaque is a promising candidate.
Implications and Unanswered Questions
- Potential Impact on Microbiome:
- The effects of obelisks on the human microbiome remain uncertain—whether they act as parasites, bring benefits, or exist as neutral passengers.
- Understanding their ecological and evolutionary significance is crucial for deciphering their potential impact on human health.
- Research Directions:
- Laboratory experiments on Streptococcus sanguinis offer a promising model to unravel fundamental aspects of obelisk biology.
- Long-term implications on human health, therapeutic potential, and the broader ecological role of obelisks warrant further exploration.
- Evolutionary Dynamics:
- The evolutionary trajectory of obelisks, their interaction with hosts, and the role they play in microbiome dynamics are areas ripe for investigation.
Conclusion
- The discovery of obelisks introduces a new dimension to the microscopic world, challenging conventional classifications.
- As research unfolds, the peculiarities of obelisks and their intricate relationships with microbial hosts promise to unravel mysteries and contribute to our understanding of the intricate web of life at the smallest scales.
