>51919 58471 IL1_beta
51919 51980 exon
52703 52764 exon
53297 53345 exon
54890 55091 exon
55638 55808 exon
56958 57088 exon
57810 58471 exon

>113076 123438 IL1_alpha
113076 113127 exon
113939 113993 exon
115117 115165 exon
116356 116584 exon
118202 118375 exon
120051 120175 exon
122149 123438 exon

This is an example of an annotation file. Like a sequence file, it should always be saved in text-only format.

All of the numbers refer to the nucleotides of the mouse Il1a genomic fragment. Because the reverse complement of the sequence displayed on the UCSC Genome Browser was used, the coding sequences of both Il1a and Il1b are on the "plus" strand of the genomic DNA. The entry for each locus starts with < or >, depending on the direction of transcription, > in this case. This is immediately followed by the range of nucleotides covered by the transcript, including introns. These numbers are the same as those on either end of the Spidey exon/intron diagram. The last entry on the line is the name of the gene in one word. Again, underscores can be used to concatenate multiple terms into a single "word".

Subsequent lines document the range of nucleotides covered by each exon followed by the word "exon". These values are taken from the "Genomic coordinates" column of the Spidey output.