The human chromosome DNA data in Ensembl release 96, here is in FASTA format.
Reading the Wikipedia article on the FASTA format, I understand the first line, prefixed with >
, is variously referred to as a "comment" or "sequence headers". However, looking at FASTA files from different sources, it appears this first line is quite variable in actual content.
What are the colon separated fields in this FASTA header (as found above on the Ensemble FTP site)? Most fields are guessable, but an explanation of each field would be much appreciated. I believe the 46709983
is the number of base-pairs in the chromosome.
>21 dna:chromosome chromosome:GRCh38:21:1:46709983:1 REF
Finally, how should I have figured out the meaning of the header notation for myself? Is there a list of common or known header formats?