biology

Metavirus

Metavirus 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 Metavirus rather than just read about it. In short: Metavirus is a genus of viruses in the family Metaviridae. They are retrotransposons that invade a eukaryotic host genome and may only replicate once the virus has infected the host.

Key takeaways

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

Reference excerpt

Metavirus is a genus of viruses in the family Metaviridae. They are retrotransposons that invade a eukaryotic host genome and may only replicate once the virus has infected the host. Metavirus may use several different hosts for transmission, and has been found to be transmissible through ovule and pollen of some plants. Metavirus contains five families of the Ty3/Gypsy element with either one or two open-reading frames (gag3 and/or pol3); these families are mdg1, mdg3, blastopia, 412, and micropia. There is evidence to support that amino acid deprivation in the elements of the host genome has frequently caused a frameshift towards the Ty3 element. Metavirus corresponds with the Ogre/Tat gene lineage.

Morphology Species of Metavirus are single-stranded RNA retrotransposons. They have an icosahedral and linear conformation and are not enclosed in an envelope. Their diameter is approximately 50 nm and they are usually between 42 and 52 nm in length.

Species The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species:

Evolution Because of their high mutation and recombination rate and their ability to conduct horizontal gene transfer, the evolutionary history of many retroelements may be challenging to trace (Benachenhou et al., 2013). Multiple taxa of Metavirus have genomic sequence that are homologous to other genera of Metaviridae and a suggest common ancestor and/or coevolution. Scientists often look at capsid proteins for evidence of Metavirus evolution.

Studies Mascagni et al. (2017) conducted researched to find homologs and identify strands in sunflower species. In the experiment, DNA was extracted from various helianthus species and the genomes of retrotransposons were identified using BLASTX analysis. Phylogenetic trees were constructed using neighbor-joining clustering method and a bioinformatic pipeline was constructed to allow genomic analysis. Two elements, SURE and Helicopia, were identified and placed into the Gypsy and Copia superfamilies, respectively. Thus, the SURE element belongs to the Gypsy group, of the Ogre/Tat lineage, of the genus Metavirus. Further analysis led Mascagni et al. (2017) to identify mutations and conclude that the Metavirus lineage evolved before Sirevirus. Mascagni et al. (2017) also found evidence that the SURE elements and Helicopia elements had hybridized, potential for new lineages. Nefedova and Kim (2009), conducted a study on Drosophila melanogaster to further identify lineages of Metavirus. Homologs were identified from previously extracted DNA of retrotransposons and Drosophila melanogaster and phylogenetic trees were constructed. Metaviruses possess the env gene, allowing them to be infective, which Nefedova and Kim (2009) concluded was obtained from horizontal gene transfer from baculoviruses. Metavirus contains the roo element which is thought to have been obtained from gene transfer from Errantivirus, or more likely, the two genera share a common ancestor.

References

External links ICTV Report: Metaviridae "Metaviridae". NCBI Taxonomy Browser. 186665. Descriptions of Plant Viruses Archived 2019-11-20 at the Wayback Machine

Worked examples

Example 1 — a first encounter with Metavirus

Start with the simplest possible case. Write down what Metavirus 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 Metavirus 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 Metavirus 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 Metavirus

In research: Metavirus 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 Metavirus 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: Metavirus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Metaviridae, RNA reverse-transcribing viruses, Virus genera, so understanding it makes those chapters shorter.
In everyday life: Look for Metavirus 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.

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How to study Metavirus in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Metavirus 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 Metavirus out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Metavirus in simple terms?

Metavirus is a genus of viruses in the family Metaviridae. They are retrotransposons that invade a eukaryotic host genome and may only replicate once the virus has infected the host.

Why does Metavirus 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 Metavirus?

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 Metavirus.