CLONAL ANALYSIS IN THE CHICKEN RETINA REVEALS TANGENTIAL DISPERSION OF CLONALLY RELATED CELLS

Development of the chicken retina was investigated through clonal anal ysis using retroviral vectors. Replication-incompetent retroviral vect ors encoding either human placental alkaline phosphatase, beta-galacto sidase, or a viral core protein were used in paired combinations to in fect retinal progenitor cells from Embryonic Days 2.5-7.0. Labeled clo nes were analyzed late in embryonic development after retinal histogen esis was complete,The early accessibility of the chicken retina, combi ned with its large final size, resulted in the labeling of much larger clones than had been reported previously in other species. The clones were composed of many cell types, supporting previous conclusions fro m other vertebrates that the progenitor cells of developing retina are multipotent. The majority of clones derived from early infections con sisted of multiple tightly clustered arrays of cells accompanied by di spersed individual cells. Clonal complexity and tangential dispersion were greater in peripheral than central retina and decreased considera bly with increasing age of infection. These observations suggest that early during retinal development, shortly after optic cup formation, t here is considerable mixing of progenitor cells. (C) 1994 Academic Pre ss, Inc.