biology

Orthopicobirnavirus

Orthopicobirnavirus is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Orthopicobirnavirus rather than just read about it. In short: Orthopicobirnavirus is a genus of double-stranded RNA viruses. It is the only genus in the family Picobirnaviridae.

Key takeaways

Orthopicobirnavirus belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Orthopicobirnavirus to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Orthopicobirnavirus from memory before moving on to harder problems.

Reference excerpt

Orthopicobirnavirus is a genus of double-stranded RNA viruses. It is the only genus in the family Picobirnaviridae. Although amniotes, especially mammals, were thought to serve as hosts, it has been recently suggested that these viruses might infect bacteria. If they do infect bacteria, then they are bacteriophages. There are three species in this genus. Associated symptoms include gastroenteritis in animals and humans, though the disease association is unclear.

Etymology Picobirnaviruses are a small (pico, Spanish for small), bisegmented (bi, Latin for two), double-stranded RNA virus. Picobirnaviruses were initially considered to be birna-like viruses, and the name was derived from birnavirus (bisegmented RNA), but the virions are much smaller (diameter 35 nm vs. 65 nm). Picobirnaviruses were first detected in humans and black-footed pigmy rice rats in 1988.

Structure Viruses in the genus are non-enveloped, with icosahedral geometries, and T=3 symmetry. The diameter is around 35–40 nm.

Genome

The genome is linear, bipartite, and composed of double-stranded RNA. It includes a segment 1 which is 2.2–2.7 kilobases (kb) in length and a segment 2 which is 1.2–1.9 kb in length. The genome codes for three to four proteins. The capsid protein gene is encoded by the second open reading frame of the larger genomic segment 1. Picobirnaviruses are divided into two genogroups on the basis of the sequence of segment 2. The RNA-dependent RNA polymerase (RdRp) is encoded by segment 2. The group viruses have been isolated from humans and other mammals, as well as birds and squamates.

Life cycle

Picobirnaviruses target intestine tissue. Entry into the host cell is achieved by penetration into the host cell. Once in the host cell, viral replication is cytoplasmic. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. The viruses are released from the cell by budding. Mammals serve as the natural host. Transmission routes are fecal-oral.

Taxonomy Picobirnaviruses were initially thought to belong to the family Birnaviridae, but later were confirmed to differ with respect to host, virion size, capsid, RNA-dependent RNA polymerase, genome size, and organization. The family Picobirnaviridae is now classified distinctly and composed of one genus Orthopicobirnavirus, which has three species:

Orthopicobirnavirus beihaiense (Beihai picobirnavirus) Orthopicobirnavirus equi (Equine picobirnavirus) Orthopicobirnavirus hominis (Human picobirnavirus)

References

External links Malik, YS (2014). "Epidemiology, phylogeny, and evolution of emerging enteric Picobirnaviruses of animal origin and their relationship to human strains". Biomed Res Int. 2014: 1–13. doi:10.1155/2014/780752. PMC 4124650. PMID 25136620. Chandra, R (1997). "Picobirnavirus, a novel group of undescribed viruses of mammals and birds: A minireview". Acta Virologica. 41 (1): 59–62. PMID 9199719. Rosen, B; Fang, ZY; Glass, RI; Monroe, SS (2000). "Cloning of Human Picobirnavirus Genomic Segments and Development of an RT-PCR Detection Assay". Virology. 277 (2): 316–29. doi:10.1006/viro.2000.0594. PMID 11080479. Taxonomic proposal for picobirnaviridae at the ICTV Viralzone: Picobirnavirus ICTV Report: Picobirnaviridae

Illustrations

Worked examples

Example 1 — a first encounter with Orthopicobirnavirus

Start with the simplest possible case. Write down what Orthopicobirnavirus claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Orthopicobirnavirus before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Orthopicobirnavirus ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Orthopicobirnavirus

In research: Orthopicobirnavirus appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Orthopicobirnavirus in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Orthopicobirnavirus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Double-stranded RNA viruses, Riboviria, Virus genera, so understanding it makes those chapters shorter.
In everyday life: Look for Orthopicobirnavirus outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Orthopicobirnavirus” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Orthopicobirnavirus in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Orthopicobirnavirus means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Orthopicobirnavirus out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Orthopicobirnavirus in simple terms?

Orthopicobirnavirus is a genus of double-stranded RNA viruses. It is the only genus in the family Picobirnaviridae.

Why does Orthopicobirnavirus matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Orthopicobirnavirus?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Orthopicobirnavirus.