Why finding genes in a genomic DNA sequence is difficult?

Question

[pablo escobar]

What's gene finding? I know that is the process of identifying the regions of genomic DNA that encode genes. But i have an incertitude: for finding genes it is not enough to look at the start and stop codons?

Answer 1

[Alex Reynolds]

There is more to a gene than what codes for a protein (or codes for the transcript that gets turned into a protein, which is where the start/stop codons partially come in).

Promoters, enhancers, intron-exon junctions, other regulatory regions, etc. are all parts of a gene that change how transcription and translation are done. Annotation of a genome with these regions requires more work, use of prediction tools, experimental validation, etc.

Part of this, as well, is that it is hard to get people to agree on what constitutes a gene. Some say functional elements that are hereditary are genes. Or are genes a subset of that, or some other set? Some reading:

1) https://genome.cshlp.org/content/genome/17/6/669.full.html

2) http://www.genetics.org/content/205/4/1353