Distinct Nuclear Architecture of Photoreceptors and Light-Induced Behaviors in Different Strains of Mice.

PURPOSE: The mouse retina is considered a remarkable model for studying gene functions. However, variations in genetic background influence phenotypes in the mammalian retina. Therefore this study aimed to investigate the effects of the genetic background on the nuclear architecture of photoreceptor cells and the light-induced behavior in C57BL/6, 129 × 1/svj, and ICR mice.

METHODS

The nuclear architecture of photoreceptor cells was investigated using various staining methods on postnatal day 21 (P21). Murine behavior was observed using a light-dark compartment test.

RESULTS

The outer nuclear layer and retina were significantly thicker in C57BL/6 mice than in 129 × 1/svj mice. The percentage of photoreceptors with one chromocenter was significantly higher in C57BL/6 mice than in 129 × 1/svj and ICR mice on P21. The numbers of photoreceptor cells in C57BL/6 and ICR mice were significantly higher than those in 129 × 1/svj mice. The behavior test revealed that the walking distance and velocity in the light compartment were increased in C57BL/6 and ICR mice compared to 129 × 1/svj mice.

CONCLUSIONS

Different mouse strains had a distinct nuclear architecture of photoreceptors on P21, and C57BL/6 and ICR mice were more active than 129 × 1/svj mice in response to light-induced stress.

TRANSLATIONAL RELEVANCE: This study demonstrates a technique for assessing retinal structures and nuclear architecture in various strains of mice, which are often used to model human retinal disease. Hence, this study may help to elucidate the effect of genetic or disease-induced variance in retinal architecture and the organization of photoreceptor nuclear content on visual function in humans.