Influence of a quantitative trait locus on mouse chromosome 19 to the light-adapted electroretinogram.

Purpose: Both implicit time and amplitude of the cone-mediated electroretinographic (ERG) b-wave differ significantly between the C57BL/6JOlaHsd and 129S2/SvHsd inbred mouse strains. The purpose of this work was to undertake a quantitative genetics study to localize the gene or genes involved.

Methods: Implicit time and amplitude of the a- and b-waves of the single-flash and flicker cone-mediated ERG were recorded as the quantitative traits in reciprocal backcrossed populations. A genome-wide scan was performed with 106 polymorphic markers. Map Manager (release QTXb20) was used to analyze the data and make phenotype-genotype correlations.

Results: A quantitative trait locus (QTL) of major effect in controlling variation in both implicit time and amplitude of the cone-mediated ERG localized to the middle of chromosome 19.

Conclusions: Mapping of a QTL influencing both implicit time and b-wave amplitude of the light-adapted ERG represents an initial step toward identifying the gene(s) responsible for this phenotypic variation.