Reproduction：Homozygote x Homozygote
Phosphodiesterase 6B (PDE6B) is a protein-coding gene that encodes a protein that is part of the cGMP phosphodiesterase (cGMP-PDE) protein complex, a peripheral membrane isomerase consisting of α, β, and γ subunits, and PDE6B encodes the β subunit of this protein. cGMP-PDE complexes are present in optic rod photoreceptor cells as part of the photoreceptor tissue at the back of the eye (retina), and the optic rod is specifically responsible for transmitting visual signals from the eye to the brain under low light conditions. When light enters the eye, photon absorption can trigger a signaling cascade in the optic rod photoreceptors that activate cGMP-PDE, leading to rapid cGMP hydrolysis, closure of cGMP-gated cation channels, and cellular hyperpolarization; these changes trigger the closure of channels in the cell membrane, resulting in the transmission of signals to the brain that is referred to as vision. In humans, mutations in the PDE6B gene lead to Retinitis pigmentosa (RP) and congenital stationary night blindness (CSNB).
This strain is a mouse Pde6b knockout model that uses gene editing technology to knock out the homolog of the human PDE6B gene in mice. The deletion of Pde6b gene expression in mice leads to dysfunction of the cGMP-PDE complex and rapid apoptosis of optic rod cell photoreceptors, causing severe retinal degeneration (RD), and the progression of ocular retinal disease in this model is similar to that of mice carrying the RD1 spontaneous mutations in the mouse Pde6b gene, which is a class of animal models of early-onset retinal degeneration.
The mouse Pde6b gene is located on chromosome 5, and exon 2-21 of this gene was knocked out using gene editing techniques.
● Retinitis Pigmentosa (RP) Research;
● Congenital Stationary Night Blindness (CSNB) Research;
● Other Eye Disease Research.
1.Electroretinogram (ERG) testing
Figure 1. Electroretinogram (ERG) results of 3-week-old RD1 mice (Ped6b-KO) and wild-type mice (C57BL/6J). Compared with wild-type mice, the amplitudes of both a- and b-waves in the scotopic and photopic ERGs of 3-week-old RD1 mice were significantly reduced, almost reaching the level of no amplitude, and the ERGs showed a waveform extinction.
2.Optical coherence tomography (OCT) of the retina
Figure 2. Optical coherence tomography (OCT) results of 11-week-old RD1 mice (Pde6b-KO) and wild-type mice (C57BL/6J). Pathological phenotypes of apoptotic optic rod cells (photoreceptor cells) and loss of the outer nuclear layer were present in the retina of RD1 mice compared with wild-type mice.
Retinal pathological evaluation of RD1 mice and wild-type mice by electroretinography (ERG) and optical coherence tomography (OCT) showed that RD1 mice exhibited rapid apoptosis of optic rod cells and loss of the outer nuclear layer compared with wild-type mice, while RD1 mice at 3 weeks of age showed a severe phenotype of almost complete extinction of the ERG waveform, the early onset of retinal degeneration in this model is sufficient considering that the mice normally start to open their eyes only at about 14 days.
In conclusion, RD1 mice are a model of early-onset and severe retinal degeneration that can be used for subsequent studies of retinitis pigmentosa (RP) and other retinal diseases, providing a useful tool for the study of human diseases.