Progesterone-independent avidin in chick oviduct fibroblast culture

The production of avidin was studied in chick oviduct cell cultures derived from immature chicks or from chicks with 4, 8, or 14 days of estrogen priming in vivo. Cells were grown for 5--7 weeks, and the monolayers formed were composed of collagen-producing fibroblasts. In some cultures, epithelial cells were also found, but only in the original explants. Two-day avidin production of cultures was measured in the media weekly. Cultures produced avidin spontaneously, the amount being fairly stable during the 7-week culture period. No difference was found in avidin production or cell morphology when estrogen-containing medium was used. Cultures from 4- to 8-day-estrogen-primed chick oviducts produced the same amount of avidin as cultures from immature oviducts, whereas further estrogen pretreatment seemed to reduce avidin production. Progesterone did not enhance avidin production with or without estrogen priming but, due to its inhibition of growth, clearly inhibited avidin when it was continuously in the culture medium. It is concluded that chick oviductal fibroblasts have an inherent capacity for avidin production and that this is independent of progesterone.