Could you tell me the steps on how to do this?
1 answer
You create the file yourself for your own data.
Kevin
Creating metadata for your data is one thing that you will have to do time and time again (i.e., a lot) in your career. It can technically be created within the coding environment itself, but is more commonly stored as an external TXT, CSV, TSV, or other file. In the worst case scenario, a collaborator will send you a 'crazy' Excel spreadsheet that has a wide range of colours, formulae, and is inconsistent (in its formatting).
In your specific case, your best option is to study the WGCNA-provided clinical trait metadata file, and then use that as a template. Here is a portion of the WGCNA-provided file (available through your link):
Mice Number Mouse_ID Strain sex DOB parents Western_Diet Sac_Date weight_g length_cm
1 F2_290 290 306-4 BxH ApoE-/-, F2 2 2002-03-22 229232 2002-05-14 2002-09-11 36,9 9,9
2 F2_291 291 307-1 BxH ApoE-/-, F2 2 2002-03-22 232 2002-05-14 2002-09-11 48,5 10,7
3 F2_292 292 307-2 BxH ApoE-/-, F2 1 2002-03-22 232 2002-05-14 2002-09-11 45,7 10,4
4 F2_293 293 307-3 BxH ApoE-/-, F2 1 2002-03-22 232 2002-05-14 2002-09-11 50,3 10,9
5 F2_294 294 307-4 BxH ApoE-/-, F2 1 2002-03-22 232 2002-05-14 2002-09-11 44,8 9,8
6 F2_295 295 308-1 BxH ApoE-/-, F2 1 2002-03-22 232 2002-05-14 2002-09-11 39,2 10,2
7 F2_296 296 308-2 BxH ApoE-/-, F2 2 2002-03-22 232 2002-05-14 2002-09-11 38,8 10,2
8 F2_297 297 308-3 BxH ApoE-/-, F2 2 2002-03-22 232 2002-05-14 2002-09-11 31,2 10,1
9 F2_298 298 308-4 BxH ApoE-/-, F2 2 2002-03-22 232 2002-05-14 2002-09-11 33,4 10
10 F2_299 299 338-1 BxH ApoE-/-, F2 2 2002-03-22 109 2002-05-14 2002-09-11 40 9,9
11 F2_300 300 338-2 BxH ApoE-/-, F2 2 2002-03-22 109 2002-05-14 2002-09-11 41,1 9,8
12 F2_301 301 338-3 BxH ApoE-/-, F2 2 2002-03-22 109 2002-05-14 2002-09-11 33,8 9,9
13 F2_302 302 338-4 BxH ApoE-/-, F2 2 2002-03-22 109 2002-05-14 2002-09-11 44 10,5
14 F2_303 303 373-1 BxH ApoE-/-, F2 2 2002-04-11 NA 2002-07-24 2002-09-11 41,9 10,1
15 F2_304 304 373-2 BxH ApoE-/-, F2 2 2002-04-11 NA 2002-07-24 2002-09-11 37,6 10,1
16 F2_305 305 373-3 BxH ApoE-/-, F2 2 2002-04-11 NA 2002-07-24 2002-09-11 34,1 10,1
17 F2_306 306 374-1 BxH ApoE-/-, F2 2 2002-04-11 NA 2002-07-24 2002-09-11 42,9 10,2
18 F2_307 307 374-2 BxH ApoE-/-, F2 2 2002-04-11 NA 2002-07-24 2002-09-11 35,3 9,8
19 F2_308 308 374-3 BxH ApoE-/-, F2 1 2002-04-14 NA 2002-07-24 2002-09-11 40,5 10
20 F2_309 309 327-1 BxH ApoE-/-, F2 2 2002-04-11 230 2002-07-24 2002-11-13 40,7 10,9
So, each row relates to a single sample. There will usually be an identifier that matches the sample names in your core / main data to this metadata, but it's not always that easy. NEVER expect that the rows in the metadata file will be ordered as per the columns in your main data.
There can be any number of traits / columns in this metadata file.
Surely you can work from here and create your own file. For other related issues, like reading a CSV file into R, the answer to those can be easily found via a search in your search engine of choice.
Yes, I understand the metadata column. What I need is (1) a file to start with i.e. a human annotation file and (2) which column(s) of this file is necessary for creating the metadata.
My expression file includes gene name as an identifier.
My apologies for it is not entirely clear what you need. You need sample (e.g. clinical traits) or gene annotation (e.g. gene biotype, position, chromosome, GO term, KEGG pathway, etc)?
Are you not referring to this part of the tutorial: https://horvath.genetics.ucla.edu/html/CoexpressionNetwork/Rpackages/WGCNA/Tutorials/Consensus-RelateModsToTraits.pdf ?
No, I am referring to this turorial. My concern is how to make the GeneAnnotation.csv file for human data. Otherwise which human annotation file (a link) should I use.
I see... You can generate your own gene annotation via biomaRt. There are quite a few examples on the online forums.
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