Pde6b-MU2 Mice

Catalog Number: C001276

Genetic Background: C57BL/6JCya

Reproduction: Homozygote x Homozygote

Tip: Ophthalmic phenotype screening is recommended due to the individual variability.

Strain Description

The PDE6B gene provides instructions to make a protein part of a protein complex called cGMP-PDE (beta sub-unit). This complex is found in specialized photoreceptor cells called optic rods. As part of the light-sensitive tissue at the back of the eye (retina), the optic rod transmits visual signals from the eye to the brain under low-light conditions. When light enters the eye, rod cell proteins are activated, including cGMP-PDE. When cGMP-PDE is activated, molecules within the rods called GMP are broken down, which triggers the closure of channels in the cell membrane. The closure of these channels leads to signal transmission to the brain, which is interpreted as vision.

Pde6b-MU2 mice are a model of autosomal recessive retinitis pigmentosa (RP) caused by a spontaneous missense point mutation in the Pde6b gene. It was shown that homozygous Pde6b-MU2 mice exhibit sclerotic retinal vessels at 4 weeks of age, progressive outer retinal nucleus degeneration beginning at 16 days of age, and progressive decreases in a- and b-waves of the electroretinogram (ERG) of the optic rods and cones. Although the phenotype is similar to that of the Rd1 model, the Pde6b-MU2 model has a later onset and less severe retinal degeneration, which may provide a better model for experimental drug treatment of retinitis pigmentosa. The homozygous Pde6b-MU2 mice are viable and fertile. The actual onset of the model may vary due to individual variability, and ophthalmic phenotypic screening is recommended before conducting formal experiments.

Application

• Retinitis Pigmentosa (RP) Research.
• Other Eye Disease Research.
  
  

Validation Data

1. Fundus morphology & OCT

Figure 1. Fundus morphology and OCT results of Pde6b-MU2 mice at different ages. Pde6b-MU2 mice have an early onset severe retinal degeneration. As Pde6b-MU2 mice aged from 6 to 96 weeks, the retinal thickness decreased, and the retinal structure became increasingly disordered.

2. Electroretinogram (ERG)

Figure 2. Electroretinogram (ERG) detection results of WT and Pde6b-MU2 mice. Compared with WT, the amplitudes of both a- and b-waves in the scotopic and photopic ERGs of 6-week-old Pde6b-MU2 mice were significantly reduced, almost reaching the level of no amplitude, and the ERGs showed a waveform extinction.

Summary

Pde6b-MU2 mice with loss of optic rod cell photoreceptors and loss of the outer nuclear layer are usable animal models of retinitis pigmentosa.