2.2 years ago by
That is implicit, the start codon should be at the first 5' CDS position, the stop codon at the 3' postion of the last CDS. Mind strand and eventual phase. Genome browsers normally don't require the start and stop codon information. Also, there is possibly a reason to not annotate the start and stop codons.
Current gene models are notoriously error prone and often based on automatic prediction only, stating an exact start codon f.e. implies a possibly undue confidence. Experimental techniques such as ribosome profiling have often delivered surprising result with respect to unexpected translation initiation sites (I'll find you a citation for that...).
(If CDS are not annotated, you have to subtract the 5'/3'Utr's from the terminal exons.)