MORPHOLOGICAL AND BIOCHEMICAL STUDIES ON THE DEVELOPMENT OF FOETAL MOUSE SKIN

SUMMARY.— It has been noted that biochemical and morphological changes occurred simultaneously during the embryogenesis of mouse skin. The onset of histological maturation of collagen fibres coincided with a change in the pattern of the in vitro incorporation of both ³⁵SO₄ into the sulphated mucopoly-saccharide and ¹⁴C-proline into the collagen of whole skin. Simultaneously, an increase in thickness and differentiation of the epidermis and changes in the basement membrane were observed. Thus, by applying a variety of techniques it has been demonstrated that a critical period of skin maturation involving dermis and epidermis is reached on the eighteenth day of embryogenesis in the mouse.