HISTOGENESIS BY CELLS FROM EMBRYONIC AND HATCHED CHICKS IN GIANT, PLATE-LIKE AGGREGATES CULTURED ON A POROUS MATRIX

¹ Department of Biology and Department of Chemical Engineering, Rice University, Houston, Texas

Tissue plate cultures on a sponge matrix were prepared from kidney or lung cells of 14- or 18-day chick embryos, of newly hatched clucks, and of chicks 2 or 4 days old. Two types of suspension were prepared from these cells and used for the cultures: suspension 1 contained single cells and cell clumps of varying size and degree of compactness, but free from organized histological structures; suspension 2 contained single cells and 2-cell clumps exclusively. In the tissue plate cultures on the three-dimensional substrate both kidney and lung cells at both embryonic stages formed giant, plate-like aggregates from either type of suspension; histogenesis in these aggregates was excellent. Kidney cells of newly hatched chicks were also able to reaggregate into extensive tissue plates from either type of suspension; reconstructed tubules were still present in these cultures although considerably less abundant. Lung cells from newly hatched chicks formed large tissue plates only from suspension 1; occasionally a bronchial tubule, a cartilage nodule or a capillary-like structure was found in the plates. Suspension 2 of lung cells from newly hatched chicks resulted in formation of small aggregates with rare indications of a histogenetic process. The same result was true for both kidney and lung cells in suspension 2 from 2- and 4-day-old chicks. The possibility is discussed that in these experiments technical reasons involved in preparation of the cultures were largely responsible for the apparent decline in aggregation and histogenesis of post-embryonic cells. In control experiments embryonic cells cultivated on Millipore filters ("two-dimensional." porous matrices) did not form extensive tissue plates or develop histological organization.