Evidence for age-dependent impairment of ovalbumin heterogeneous nuclear RNA (HnRNA) processing in hen oviduct

The expression of the ovalbumin gene in hen oviduct decreases during ageing. Northern transfer of electrophoretically fractionated total RNA from oviducts of mature egg-laying and old non-egg-laying hens, and hybridization to nick-translated plasmid pOV230 (ovalbumin complementary DNA cloned into pMB9) revealed with age increasing concentrations of distinct high-molecular-weight ovalbumin pre-mRNA species as compared with that of functional 18S ovalbumin mRNA. The accumulation of ovalbumin sequence-containing processing intermediates in old hen oviducts indicates lowered rates of RNA splicing and/or altered steady state concentrations of splicing intermediates during post-transcriptional maturation of heterogeneous nuclear RNA in old animals.