What are the pathways of mRNA degradation?

There are two general pathways of mRNA degradation in eukaryotes. In both pathways, the first step involves deadenylation or the exonucleolytic removal of the poly (A) tail. In the first pathway, deadenylation is followed by the hydrolysis of the cap, after which the mRNA body is progressive degraded by a 5' exonuclease. In the second pathway, a complex of 3' exonucleases degrades the mRNA body. This is followed by the hydrolysis of the remaining cap structure.