DISTRIBUTION OF VITRONECTIN MESSENGER-RNA DURING MURINE DEVELOPMENT

Vitronectin (Vn) is not only a major adhesive glycoprotein in plasma b ut also regulates cell-mediated proteolytic enzyme cascades, including the complement, coagulation, and fibrinolytic systems. This broad fun ctional activity suggests that Vn may also play a critical role in dev elopment. To bean to investigate this possibility, we studied Vn gene expression during murine embryogenesis, In situ hybridization analysis of embryonic tissues revealed Vn mRNA primarily in the liver and the central nervous system (CNS). In the liver, Vn mRNA was detected by da y 10, the level increasing at later developmental stages. In the CNS, Vn mRNA was also detected as early as day 10 and was confined to the f loor plate. However, as development proceeded, high levels of Vn trans cripts became prominent in the meninges of the cortex and spinal cord, and in close proximity to brain capillaries. The perikarya of most ne urons lacked Vn mRNA. Unexpectedly, high levels of Vn mRNA were associ ated with capillaries of the CNS, but not with blood vessels of periph eral organs. These results indicate that Vn is expressed in a spatiall y and temporally distinct pattern during murine embryogenesis, and sug gest that the Vn transcript may be a CNS-specific vascular marker. (C) 1995 Wiley-Liss, Inc.