Pde6b-MU1 Mice

Catalog Number: C001277

Reproduction: Homozygote x Homozygote

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 turned on (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-MU1 mice are a model of autosomal recessive retinitis pigmentosa (RP) caused by a spontaneous mutation in exon 7 of the Pde6b gene that leads to the accumulation of intracellular cyclic guanosine monophosphate (cGMP), which causes massive apoptosis of optic rod cells within a few weeks of birth. This type of mutation causes blindness in mice at the stage of lactation and the homozygous Pde6b-MU1 mice are viable and fertile. Pde6b-MU1 mice have undergone multiple strain crosses and rounds of hybridization during breeding and preservation, resulting in three different coat colors: white, brown, and black. Internal data shows that Pde6b-MU1 mice of the three different coat colors exhibit similar pathological features, including rapid apoptosis of rod photoreceptor cells and outer nuclear layer loss, which are typical phenotypes of retinal pigment degeneration. Due to the pigment synthesis disorder in white mice, the retinal pigment epithelium lacks black pigment granules, making it unsuitable for observing fundus lesions. Therefore, Cyagen will prioritize the supply of Pde6b-MU1 mice with black coat color.

Application

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

Coat Color

Figure 1. Pde6b-MU1 mice exhibit different coat colors. Due to multiple strain crosses, this mouse strain displays three different coat colors: white, brown, and black.

Validation Data

1. Fundus morphology & OCT

Figure 2. Fundus morphology and OCT results of WT and Pde6b-MU1 mice with different fur colors. No matter if the fur is black or white, Pde6b-MU1 mice have an early onset severe retinal degeneration, but mice with black fur are easier to observe.

2. Electroretinogram (ERG)

Figure 3. Electroretinogram (ERG) detection results of WT and Pde6b-MU1 mice. Compared with WT, the amplitudes of both a- and b-waves in the scotopic and photopic ERGs of 3-week-old Pde6b-MU1 mice were significantly reduced, almost reaching the level of no amplitude, and the ERGs showed a waveform extinction.

Summary

Pde6b-MU1 mice with loss of optic rod cell photoreceptors and loss of the outer nuclear layer are usable animal models of retinitis pigmentosa.