Skin Morphology of the Mutant Hairless USP Mouse

The study investigated the skin morphology of mutant hairless USP mice compared to BALB/c mice, revealing that hrUSP mice developed cystic formations, such as utricles and dermal cysts, which increased in size and number with age, leading to significant skin thickening by 8 months. Despite these changes, no qualitative differences were found in structural components like collagen and elastic fibers between the two groups. The hrUSP mutation resulted in a unique pattern of hair loss and skin morphology, characterized by enlarged cysts, but did not affect other skin components. The mice became completely hairless by 16 days, developed wrinkled skin, and had long curved nails, with a thin epidermis and a dermis rich in cysts originating from hair follicles. The study noted that hairless skin lesions began when the dermal papilla became isolated, with cysts filling the dermis, although all normal skin components were present despite altered distribution.