A Population Study of Common Ocular Abnormalities in C57BL/6Nrd8Mice

Abstract

PurposeThe purpose of this study was to quantify the frequency and severity of ocular abnormalities affecting wild-type C57BL/6N mice, the most common strain used worldwide for the creation of single-gene knockouts.MethodsA total of 2773 animals (5546 eyes) were examined at one colony at UC Davis and in three more colonies at the Institut Clinique de la Souris in Strasbourg, France. Mice were examined at 15 to 16 weeks postnatal age by performing anterior segment biomicroscopy, posterior segment examination by indirect ophthalmoscopy, intraocular pressure measurement, and optical coherence tomography of anterior and posterior segment structures.ResultsCommon ocular findings in the C57BL/6N strain included corneal deposits (3%), increased optical density of the anterior lens capsule (67%), punctate nuclear cataracts (98%), vitreous crystalline deposits (61%), hyaloid vascular remnant (6%), and retinal dysplasia attributed to the rd8 mutation (58%). Interestingly, retinal dysplasia was more common in male mice in all four breeding colonies evaluated in this study. The thickness of ocular tissues and compartments were measured by spectral-domain optical coherence tomography, including the central cornea, anterior chamber, vitreous, and retinal layers. Intraocular pressure was measured by rebound tonometry.ConclusionsOcular abnormalities are common in anterior and posterior segments of the C57BL/6N mouse, the most common background on which single-gene knockout mice have been made. It is important that vision scientists understand the extent and variability of ocular findings associated with this particular genetic background of mice.

An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface

“…280 In contrast, naturally acquired ocular surface pathology is much less common in rabbits 281,282 and is rare in mice and rats. [283][284][285]…”

Cohen Syndrome-Associated Cataract Is Explained by VPS13B Functions in Lens Homeostasis and Is Modified by Additional Genetic Factors

“…During our study, the creation and behavioral analysis of another mouse model for CS ( Vps13b 2 – / – ) was reported by Kim et al 48 Interestingly, they reported having found no sign of retinal dystrophy and did not mention the presence of cataract in their model, in spite of its being on the C57Bl/6N background, which is susceptible to both retinal and lens alterations. 27 , 49 However, no information on the ophthalmic examinations they performed is provided in the article. A more thorough report of their investigation would be necessary to comprehend the differences between our models.…”

Endogenous Apelin Is Protective Against Age-Associated Loss of Retinal Ganglion Cells in Mice

“…In the present study, we used apelin-KO mice and their WT controls mice maintained on a C57BL/6N background. C57BL/6N mice are a common strain used worldwide for the creation of single-gene KOs, but the mice carry an rd8 mutation and several ocular abnormalities (Mattapallil et al, 2012;Moore et al, 2018). We examined the rd8 mutation in our mice and observed the presence of the rd8 mutation in homozygous form in both WT mice and apelin-KO mice (Supplementary Figure S1).…”