par-5 mRNA isoform selection seemed constant in worms of the same stage but varied considerably during development: total
par-5 mRNA abundance decreased during embryogenesis, but the relative amounts of
par-5::utr.1 and
par-5::utr.2 increased significantly, peaking at the first larval stage. During postembryonic development,
par-5 mRNA isoform selection shifted progressively toward the short 3' UTR isoform,
par-5::utr.3, in line with the general tendency for C. elegans 3' UTRs (Mangone et al., 2010). This elaborates the results of Wang and Shakes (1997), indicating that both
par-5 isoform selection and mRNA expression change during development.A progressive increase in PAR-5 protein levels could also be observed during embryogenesis, coincident with an increased contribution of
par-5::utr.2.