Selective degradation of nonsense beta-phosphodiesterase mRNA in the heterozygous rd mouse

Invest Ophthalmol Vis Sci. 1998 Dec;39(13):2529-36.


Purpose: To investigate the molecular mechanism relating phenotype and genotype in the rd mouse, mRNA and pre-mRNA levels derived from the wild-type and position-347 nonsense mutant beta-phosphodiesterase (beta-PDE) genes were determined and compared with the corresponding gene copy ratios.

Methods: Total RNA and genomic DNA was isolated from the retinas of three heterozygous rd/+ mouse strains. For each, quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the ratio of wild-type and rd beta-phosphodiesterase pre-mRNA and mature mRNA. The gene copy ratio between wild-type and rd beta-PDE was also determined by quantitative PCR.

Results: The pre-mRNA ratio of wild-type versus nonsense mutant was close to 1:1, whereas the corresponding mRNA ratio was greater than 3:1, even though the gene copy ratio was confirmed to be 1:1.

Conclusions: The equivalence of pre-mRNA ratio level for wild-type and nonsense mutant in the rd/+ retina indicates that both genes were transcribed at similar levels. Thus, neither the nonsense mutation at position 347 nor the intron 1 retroviral insertion also present in the rd gene seem to have affected gene transcription. In contrast, the strain-independent bias favoring wild-type mature mRNA in vivo suggests a specific degradation of mutant transcript during or after pre-mRNA splicing. This allele-specific degradation serves to decrease mutant transcript levels dramatically in all rd strains, and suggests that photoreceptor cells have the capacity to reduce the level of an mRNA containing a nonsense mutation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3',5'-Cyclic-GMP Phosphodiesterases / genetics
  • 3',5'-Cyclic-GMP Phosphodiesterases / metabolism*
  • Animals
  • Cyclic Nucleotide Phosphodiesterases, Type 6
  • DNA / analysis
  • DNA Primers / chemistry
  • Eye Proteins / genetics
  • Eye Proteins / metabolism*
  • Female
  • Gene Dosage
  • Mice
  • Mice, Mutant Strains
  • RNA / analysis
  • RNA, Messenger / metabolism*
  • Retina / enzymology*
  • Retinal Degeneration / enzymology*
  • Retinal Degeneration / genetics
  • Reverse Transcriptase Polymerase Chain Reaction


  • DNA Primers
  • Eye Proteins
  • RNA, Messenger
  • RNA
  • DNA
  • 3',5'-Cyclic-GMP Phosphodiesterases
  • Cyclic Nucleotide Phosphodiesterases, Type 6
  • Pde6b protein, mouse