Chondrogenesis and cell proliferation in limb bud cell cultures treated with cytosine arabinoside and vitamin A

Mesenchyme cells derived from limb buds of day 10 mouse embryos were plated out at confluent and sub-confluent cell densities. Cells in confluent cultures multiplied and differentiated into chondrocytes. The addition of vitamin A to the culture medium inhibited both cell proliferation and chondrogenesis. However, cytosine arabinoside, which also inhibited growth, did not block chondrogenesis. This indicates that the inhibition of growth in the vitamin A-treated cultures did not necessarily contribute to the inhibition of chondrogenesis. Cells in sub-confluent cultures multiplied but did not differentiate into chondrocytes. In contrast to confluent cultures, vitamin A did not inhibit growth in sub-confluent cultures. This observation suggests that vitamin A may inhibit growth by causing contact inhibition.