Among the AS-NMD genes related to metabolism are the S-adenosyl-L-methionine (SAM) synthetase (sams) genes sams-3 and sams-4. 

SAM synthetase activity autoregulates sams gene expression through AS-NMD in a negative feedback loop. We furthermore find that METT-10, the orthologue of human U6 snRNA methyltransferase METTL16, is required for the splicing regulation in vivo, and specifically methylates the invariant AG dinucleotide at the distal 3' splice site (3'SS) in vitro. Direct RNA sequencing coupled with machine learning confirms m⁶A modification of endogenous sams mRNAs. 

Overall, these results indicate that homeostasis of SAM synthetase in C. elegans is maintained by alternative splicing regulation through m⁶A modification at the 3'SS of the sams genes.