Variation of the response to the optokinetic drum among various strains of mice.

The optokinetic drum has become an appropriate tool to examine visual properties of mice. We performed baseline measurements using mice of the inbred strains C3H, C57BL/6, BALB/c, JF1, 129 and DBA/2 at the age of 8-15 weeks. Each individual C57BL/6, 129 and JF1 mouse was reliably identified as non-affected in vision by determining head-tracking responses. C3H mice were used as negative control because of their inherited retinal degeneration; as expected, they did not respond to the moving stripe pattern. Surprisingly, BALB/c and DBA/2 mice showed the same result. Electroretinography, funduscopy and histology of BALB/c mice did not reveal any abnormality concerning the structure or function of the retina and the remaining eye. Therefore, it might be assumed that BALB/c mice suffer from disturbances of the central visual system. Preliminary results from linkage analysis of the non-responding phenotype in the BALB/c mice indicate a recessive, monogenic mode of inheritance; the causative gene is located on chromosome 7, but significantly different from the albino locus. In conclusion, C57BL/6, 129 and JF1 represent appropriate inbred strains for high throughput screenings with the optokinetic drum.