The issue is you’re going to get massive mutations building up in anything that doesn’t have the significant error correcting capability of DNA. So while the co

The issue is you’re going to get massive mutations building up in anything that doesn’t have the significant error correcting capability of DNA. So while the coding is not direct, it still has to somehow be in DNA so that the trait will be conserved over the generations. Shorter term changes could conceivably be stored in other molecular structures, though. (Think patterns of methylation in epigenetics or even the fringe idea of RNA memory.) I would suspect really basic things like replication would be stored somehow in DNA (nuclear DNA, mitochondrial DNA, etc) as they must be highly conserved and mutation resistant in order for organisms to survive and reproduce.