Nystagmus in the B6(CG)Tyr(c-2J)/J Albino Mouse: A Functional and RNAseq Analysis

PURPOSE: Infantile nystagmus syndrome (INS) is a gaze-holding disorder characterized by conjugate, uncontrolled eye oscillations that can result in significant visual acuity loss. INS is often associated with albinism, but the mechanism is unclear. Albino mice have nystagmus; however, a pigmented mouse with a tyr mutation making it phenotypically albino, the B6(CG)-Tyr(c-2J)/J (B6 albino), had not been tested. We tested optokinetic nystagmus reflexes (OKN) in B6 albino and control mice. RNA-Seq was performed on extraocular muscles (EOM), tibialis anterior muscle (TA), abducens (CN6), and oculomotor (CN3) neurons to uncover molecular differences that could account for nystagmus. Two genotypes of mice used are B6(CG)Tyr(c-2J)/J and C57BL/6. The B6(CG)Tyr(c-2J)/J is an albino mouse, C57BL/6 is a pigmented mouse. For each genotype there were four replicated of four types of tissues taken, these tissues were the extraocular muscles, the tibialis anterior, the oculormoter neuron, and the abducen motor neuron.