<p>If an inversion were just reversed then there would be 3' -> 3' bonds and 5' -> 5' bonds. That's why inversions are reverse complemented, you then maintain the normal 5'->3' direction. This is nicely covered <a href="https://biology.stackexchange.com/questions/44550/how-to-read-this-dna-inversion-diagram">over on our biology sister site</a>, which also includes this image:</p>

<p><img src="https://i.sstatic.net/ijaLQ.png" alt="DNA inversion"></p>

CC BY-SA 3.0
2017-10-21T20:55:26.510Z
Thanks for the link. The image you posted made it clear for me. The key is to look at both strands at the same time.
Paghillect
CC BY-SA 3.0
2017-10-21T13:42:45.293Z
2017-10-21T13:42:45.293Z
Devon Ryan
<p>I can’t quite understand the way inversions are defined. In particular I expect an inversion to be only a reversed version of the reference and not its reverse complement. Most sources use diagrams such as below which totally obscure the fact that it is also complemented.</p>

<p><a href="https://i.sstatic.net/l6xbU.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/l6xbU.jpg" alt="enter image description here"></a></p>

<p>Could someone provide an explanation on what causes an inversion and why it is defined the way it is?</p>

<ngs><structural-variation>
Why are inversions defined as the reverse complement and not just the reverse of the reference?
# Why are inversions defined as the reverse complement and not just the reverse of the reference?

(Asked by: username_0 on 2017-10-20)

I can’t quite understand the way inversions are defined. In particular I expect an inversion to be only a reversed version of the reference and not its reverse complement. Most sources use diagrams such as below which totally obscure the fact that it is also complemented.

[![enter image description here](https://i.sstatic.net/l6xbU.jpg)](https://i.sstatic.net/l6xbU.jpg)

Could someone provide an explanation on what causes an inversion and why it is defined the way it is?

**Tags:** ngs, structural-variation

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## 1 answers

### Answer by username_1 on 2017-10-21. Score: 6 | Accepted answer

If an inversion were just reversed then there would be 3' -> 3' bonds and 5' -> 5' bonds. That's why inversions are reverse complemented, you then maintain the normal 5'->3' direction. This is nicely covered [over on our biology sister site](https://biology.stackexchange.com/questions/44550/how-to-read-this-dna-inversion-diagram), which also includes this image:

![DNA inversion](https://i.sstatic.net/ijaLQ.png)

> **Comments:**
> **username_0**: Thanks for the link. The image you posted made it clear for me. The key is to look at both strands at the same time.  

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