Transferrin concentration and location during formation of chick retina: developmental correlates

The amount of transferrin in chick retina was measured during development and compared to transferrin location seen immunocytochemically. Between embryonic day 6 (E6), and 5 days post hatching, two periods occur in which transferrin concentrations rise sharply and decline. During the first, transferrin concentration rises 5-fold between E6 and 10, then rapidly declines by E14. A second increase begins on E17 and peaks by E19-20. Immunocytochemical findings demonstrate that during the first rise in concentration, transferrin is located primarily in neuritic layers. Later in development, when levels again increase, newly forming photoreceptor outer segments are strongly transferrin positive. These findings are discussed in light of developmental events occurring during retinal maturation.