Related Experiment Video
Updated: Aug 7, 2025
09:50
Single Cell Micro-aspiration as an Alternative Strategy to Fluorescence-activated Cell Sorting for Giant Virus Mixture Separation
Published on: October 27, 2019
7.1K
ICTV Virus Taxonomy Profile: Sphaerolipoviridae 2023
Tatiana A Demina1, Mike Dyall-Smith2,3, Matti Jalasvuori4
1Department of Microbiology, Faculty of Agriculture and Forestry, and Helsinki Institute of Sustainability Science (HELSUS), University of Helsinki, Helsinki, Finland.
The Journal of General Virology
|March 14, 2023
Summary
Sphaerolipoviridae are viruses with double-stranded DNA genomes that infect haloarchaea. These non-enveloped viruses possess unique icosahedral structures with spike complexes, and a narrow host range, exhibiting a lytic life cycle.
Area of Science:
- Virology
- Microbiology
- Structural Biology
Background:
- The family Sphaerolipoviridae comprises viruses with unique structural and genomic features.
- These viruses infect haloarchaea, a group of archaea thriving in saline environments.
Purpose of the Study:
- To summarize the key characteristics of the Sphaerolipoviridae family.
- To provide an overview of their morphology, genome, and host interactions.
Main Methods:
- Review and synthesis of data from the International Committee on Taxonomy of Viruses (ICTV) report.
- Analysis of viral structure, genome composition, and life cycle.
Main Results:
- Sphaerolipoviridae possess non-enveloped, tailless icosahedral virions with an internal lipid membrane.
- Their genome is a linear double-stranded DNA (~30 kbp) with inverted terminal repeats and terminal proteins.
- Capsids exhibit T=28 dextro symmetry, composed of two major capsid proteins, with spike complexes at fivefold vertices.
Conclusions:
- Sphaerolipoviruses have a narrow host range, infecting Halobacteria.
- They exhibit a lytic life cycle, essential for understanding archaeal virus-host dynamics.
Related Concept Videos
01:29Viruses of Archaea
46
Archaeal viruses play a crucial role in the ecosystems of extremophilic archaea, particularly those belonging to the phyla Euryarchaeota and Crenarchaeota. By shaping host evolution and facilitating gene transfer, these viruses influence microbial communities and contribute to genetic diversity in extreme environments. The archaea they infect thrive in acidic hot springs and hydrothermal vents characterized by high temperatures and low pH. Archaeal viruses exhibit remarkable structural...
46
01:29Viruses with RNA Genomes
66
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
66
01:29Subviral Agents
59
Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely...
59
01:30Bacterial Phylum Spirochaetes
50
Spirochetes, unique bacteria in the phylum Spirochaetes, are gram-negative, motile, tightly coiled, slender, and flexible. They inhabit aquatic sediments and animals, with some causing diseases like syphilis. Spirochetes are classified into eight genera based on habitat, pathogenicity, phylogeny, and characteristics.Their distinctive motility arises from endoflagella, located within the cell’s periplasm. These endoflagella anchor at the cell poles and extend along the cell length, encased...
50
01:26Bacterial Phylum Bacteroidota
61
The phylum Bacteroidota includes over 700 species classified into four primary orders: Bacteroidales, Cytophagales, Flavobacteriales, and Sphingobacteriales. These gram-negative, non-sporulating rods exhibit saccharolytic capabilities and can be aerobic or fermentative, encompassing obligate aerobes, facultative aerobes, and obligate anaerobes. Many species display gliding motility, though some are nonmotile or use flagella. The genus Bacteroides is well-studied due to its significant role in...
61
01:30Lytic Cycle of Bacteriophages
71.3K
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
71.3K