Lens aplasia: a new mutation producing lens abnormality in the mouse

One female with bilaterally closed eyelids was observed in a breeding colony of BALB/c mice in our laboratories. This eye abnormality was considered to be heritable because offspring with the same abnormality were produced from the mating of this female with a normal male littermate. From the results of various crosses made to determine the mode of inheritance, this abnormality is considered to be attributable to a mutation on a single autosomal recessive gene. Histologic observations of 30-day-old and adult mutant mice revealed various eye abnormalities such as microphthalmia, aphakia, absence of the anterior chamber, dystrophy of the cornea and vitreous body, and retinal disorganization. Observations of fetal eye development from days 9 to 17 of gestation, indicated that the eye developed normally until the start of invagination of the lens placode at day 10. However, formation of the lens vesicle progressed abnormally to form a mass of cells without a cavity at day 11; this mass was reduced in size at day 12 and had vanished by day 13 or 14 of gestation. Also abnormal development was observed in the cornea, vitreous body, or retina after day 12 of gestation. Complementary mating between mice homozygous for this mutation and homozygous aphakia mice, which have similar modes of inheritance and lens development, produced no F1 newborns with abnormal eyes. From these results, the present mutation is considered to be a new one. Because lens development in this mutant is disrupted at an early stage and the anlage vanishes soon after, we propose the name lens aplasia, with the suggested symbol "lap."(ABSTRACT TRUNCATED AT 250 WORDS)