Abstract
The kidneys of six slaughtered Japanese black cattle that were homozygotic with Claudin-16 (CL-16) deficiency were examined pathologically. Three cases showed signs of growth retardation and emaciation, while the other three cases showed no significant clinical signs. All cases had renal lesions showing similar morphological features. Their bilateral kidneys were small with a granulated surface. Histopathologically, in all cases, streaky, focal lesions were scattered from the cortex to the outer zone of the medulla, and the degree of renal lesions were characterized by individual variations. There were small renal tubules and irregularly shaped renal tubules with hypertrophic basement membrane in the lesions. The tubulointerstitium was widened and mesenchymal cells existed in the lesions. The renal abnormality was histopathologically diagnosed as renal tubular dysplasia. In the six cases, the renal lesions and clinical signs were diverse, and it was considered that the symptomsrelated to homozygote for CL-16 deficiency were irregular.
