Lack of DNase I mRNA sequences in murine lenses.

Clarity of the mammalian lens is due in part to the complete lack of internal organelles, including nuclei, within the lens fiber cells that compose the bulk of the lens. Experimental evidence shows that as the differentiation of lens fiber cells progresses, nuclei and nuclear DNA are actively degraded. Prior characterization of chick lens development suggests that DNase I could be involved in lens DNA degredation. However, recent data suggest that DNase I is unlikely to be the nuclease responsible for DNA degredation in the differentiating lens. In this report, we find that in the murine lens, mRNA for DNase I is undetectable by northern blotting or PCR. We conclude that mRNA for DNase I is either not present or present in very low levels in murine lens. Our results are consistent with the hypothesis that DNase I is not involved in lens DNA degredation.