# If v3v4 is annotated according to GG database, is there a fixed range of OTU table rows

**URL:** https://forum.qiime2.org/t/if-v3v4-is-annotated-according-to-gg-database-is-there-a-fixed-range-of-otu-table-rows/18181
**Category:** User Support
**Created:** [January 22, 2021, 2:18pm UTC](https://forum.qiime2.org/t/if-v3v4-is-annotated-according-to-gg-database-is-there-a-fixed-range-of-otu-table-rows/18181 "2021-01-22T14:18:11Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![zhangyun](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/z/f6c823/32.png) [@zhangyun](https://forum.qiime2.org/u/zhangyun)
#### Post date: [January 22, 2021, 2:18pm UTC](https://forum.qiime2.org/t/if-v3v4-is-annotated-according-to-gg-database-is-there-a-fixed-range-of-otu-table-rows/18181/1 "2021-01-22T14:18:11Z")

</div>

Hi,Is there a fixed range of OTU table rows obtained by species annotation in GG database? A thousand samples run 120000 lines, and a hundred samples run 10000 lines.The same bacteria in OTU can find 850 lines. Is this normal？Thank you very much for your reply！

---

<div class="post-metadata">

### Author: ![Nicholas\_Bokulich](https://forum.qiime2.org/user_avatar/forum.qiime2.org/nicholas_bokulich/32/19937_2.png) [@Nicholas\_Bokulich](https://forum.qiime2.org/u/Nicholas_Bokulich)
#### Post date: [January 26, 2021, 7:16am UTC](https://forum.qiime2.org/t/if-v3v4-is-annotated-according-to-gg-database-is-there-a-fixed-range-of-otu-table-rows/18181/2 "2021-01-26T07:16:28Z")

</div>

Hi @zhangyun,

> [@zhangyun](#):
>
> Is there a fixed range of OTU table rows obtained by species annotation in GG database?

No. It depends on the number of query sequences that you have

> [@zhangyun](#):
>
> A thousand samples run 120000 lines, and a hundred samples run 10000 lines.

Probably because you have different numbers of query sequences associated with those different samples.

> [@zhangyun](#):
>
> The same bacteria in OTU can find 850 lines.

Multiple query sequences can be classified to the same taxonomic lineage, and this commonly occurs. Just because OTUs represent unique sequence clusters does not imply that these map to unique taxonomic lineages.

Good luck!

---

<div class="post-metadata">

### Author: ![system](https://forum-qiime2-org.s3.dualstack.us-west-2.amazonaws.com/original/3X/2/1/21af5fe23cb6f4579467c66a9ed94e55274ca7bd.svg) [@system](https://forum.qiime2.org/u/system)
#### Post date: [February 26, 2021, 1:16pm UTC](https://forum.qiime2.org/t/if-v3v4-is-annotated-according-to-gg-database-is-there-a-fixed-range-of-otu-table-rows/18181/3 "2021-02-26T13:16:31Z")

</div>

This topic was automatically closed 31 days after the last reply. New replies are no longer allowed.