Day 149 has 26 protein-coding genes (browser view) and is home to the T cell receptor gamma (TCRG) locus.
In order to recognize a broad range of foreign invaders, T cells shuffle the receptors that they use. This locus has a set of genes that are mixed and matched to make many possible different receptors; this particular locus is used by gamma/delta T cells.
Click here to see all 8386630 letters of Day 149 with one of the T cell gamma receptor subunits underlined.