Day 221 has 95 protein-coding genes (browser view) and has an interesting case of a “read-through” or “conjoined” gene: ZFP91-CNTF.
These genes individually are transcribed and encode functional proteins, but sometimes get transcribed as a single RNA together – the polymerase keeps going past the end of ZFP91 and reads into CNTF, but then stops before the end. This transcript gets destroyed by the NMD pathway before it is ever read.
Click here to see all 8442914 letters of Day 221 with ZFP91-CNTF underlined.