Here is the question that comes to my mind when I cogitate about this recent paper … “Is the bacterial pan-genome open or closed?”
Authors suggest that on average, a bacterial genome is composed of the following three gene family pools:
1) extended core: basically essential genes
2) accessory genes: rare gene families seen in only a small subset of sampled bacterial genomes
3) character genes: everything in between. these genes are seen in a subset of sampled bacterial genomes
So what do you think? Is the accessory gene family pool open or closed? My opinion, closed. There, I said it.
