Established cell lines from different groups of vertebrates undergo metabolic cooperation with one another.

The prelabeled-donor technique was used to study metabolic cooperation in the established cell lines, RTG-2, FHM, and IgH-2, which are respectively from rainbow trout, fathead minnow, and green iguana. The donors were grown with [3H]hypoxanthine for 3 h after which the radioactive medium was removed and the recipients, marked by the presence of latex beads, were added. Cells from each of these lines were capable of cooperating with themselves and with one another because after 5.5 h the recipients in contact with donors were more significantly labeled than those that were not in contact. Cells FHM and IgH-2 were grown with HGPRT-Chinese hamster fibroblasts, CHW-1102, in the presence of [3H]hypoxanthine. In all cases the CHW-1102 cells that were in contact with the nonmammalian cells were more heavily labeled than those that were not in contact. Thus cells from a fish and a reptile undergo metabolic cooperation with cells from a mammal.