Genome-wide analysis of 4-day old (P4) Tdrd7 null mouse lens

Analysis of Tdrd7 deficiency in mouse lens epithelial-derived cell line at gene expression level. The hypothesis tested was that Tdrd7 is involved in post-transcriptional control of gene expression in the lens. Results provide evidence for differential regulation of genes involved in lens homeostasis and cataract formation in the absence of Tdrd7. In eukaryotic cells, cytoplasmic RNA granules (RGs) function in the post-transcriptional control of gene expression. However, the involvement of RGs and their component proteins in vertebrate organogenesis is unknown. We report two independent cases of pediatric cataract with loss-of-function mutations in TDRD7, which encodes a Tudor domain RNA binding protein. TDRD7 deficiency in chick lens produces cataracts, and Tdrd7 null mouse mutants develop cataracts, as well as features of glaucoma and male sterility due to azoospermia. In lens fiber cells, TDRD7 is necessary for the RG-mediated post-transcriptional control of critical lens mRNAs, while in the testis it functions as a component of a specialized RG, the chromatoid body. These findings define a new role for RGs in vertebrate organogenesis, and a novel mechanism for cataractogenesis. Total RNA obtained from P4 Lens from Tdrd7 null mice compared to that of Tdrd7 heterozygous mice.