The expression of the gene asebia in the laboratory mouse: I. Epidermis and dermis

Abstract

SUMMARYMice homozygous for the asebia mutation (ab/ab), which have defective sebaceous glands, display abnormalities in several other aspects of the integument. Histological sections showed that hyperplasia of the cellular layers and the stratum corneum of the epidermis is apparent at birth and increases markedly with age. Enlarged intercellular spaces are also noted in the epidermis. The thicker dermal layer of the asebic mice is characterized by increased vascularity, increased cellularity and the abnormal morphology of a large proportion of the ‘fibroblast’ population. Electron microscopy demonstrated the many abnormalities in the dermal fibroblasts as well as large amounts of cellular debris in the surrounding matrix. Collagen and elastin show alterations at the light microscopic and ultrastructural levels. Many features of the asebic dermis resemble those found with mild inflammation and with the lysosomal storage diseases. Changes in the dermis of asebic foetuses were noted prior to epidermal alterations and may mediate the latter.