PRE-METATARSAL SKELETAL DEVELOPMENT IN TISSUE-CULTURE AT UNITGRAVITY AND MICROGRAVITY

Explant organ culture was used to demonstrate that isolated embryonic mouse pre-metatarsal mesenchyme is capable of undergoing a series of d ifferentiative and morphogenetic developmental events. Mesenchyme diff erentiation into chondrocytes, and concurrent morphogenetic patterning of the cartilage tissue, and terminal chondrocyte differentiation wit h subsequent matrix mineralization show that cultured tissue closely p arallels in vivo development. Whole mount alizarin red staining of the cultured tissue demonstrates that the extracellular matrix around the hypertrophied chondrocytes is competent to support mineralization. In tensely stained mineralized bands are similar to those formed in pre-m etatarsals developing in vivo. We have adapted the culture strategy fo r experimentation in a reduced gravity environment on the Space Shuttl e. Spaceflight culture of pre-metatarsals, which have already initiate d chondrogenesis and morphogenetic patterning, results in an increase in cartilage rod size and maintenance of rod shape, compared to contro ls. Older pre-metatarsal tissue, already terminally differentiated to hypertrophied cartilage, maintained rod structure and cartilage phenot ype during spaceflight culture. (C) 1994 Wiley-Liss, Inc.