Some histochemical and biochemical observations on the lymphatic tissues of highly inbred white Leghorns

Lymphatic tissues of inbred lines of White Leghorn chickens and 20‐day embryos (inbreeding coefficient exceeds 95%) were used in the experiments, e.g. line 6 was susceptible, line 7 was resistant, and line 15 I was intermediate in response to the virus. Enzyme reactions were studied in cryostat‐cut sections of tissues and in tissue minces by colorimetric procedures. Numbers of isozymes and proteins of lymphatic tissues were resolved by disc gel electrophoresis. Colorimetric tests showed that intensities of lactate, malate, isocitrate and succinic dehydrogenase catalyzed reactions were higher in the bursae of 15 I 20‐day embryos than they were in bursae of either line 6 or 7 embryos. Intensity of dehydrogenase reactions of the spleen (15 I embryos) exceeded that found in line 6 and 7 embryos. Intensity of diaphorase reactions in the spleen and thymus was fairly uniform in all lines of embryos. Intensity of DPN diaphorase reactions in the bursae of line 15 I embryos exceeds that found in either line 6 or 7 embryos. Intensity of enzyme reactions leveled off to become fairly uniform in lymphatic tissues of chickens 3–4 weeks post hatching with the exception that dehydrogenase reactions were less intense in the thymus of 15 I chickens. Photodensitometer scans of acrylamide gel columns showed that proteins of line 6 lymphatic tissues combined with less Amido black 10B than lymphatic proteins of either line 15 I or 7 embryos. There was fairly good agreement between concentrations of strong mobility (components 1–9) and weak mobility (components 10–16) in lymphatic tissues of all lines of embryos with the exception that strong mobility proteins were about twice as concentrated in line 15 I bursae. Variable numbers of lactate isozymes were found in the lymphatic tissues of 20‐day embryos.