Developmental Changes of Duckling Liver and Isolation of Primary Hepatocytes

SIMPLE SUMMARY: The liver is the main site of fat synthesis in poultry, which participates in metabolic regulation. Although ducks are important poultry with high economic value, studies showing the liver development and isolation of primary hepatocytes of ducklings is still limited. Based on this, we observed morphological changes in duckling livers from the embryonic period to the first week after hatching, and hepatocytes were isolated from 21-day-old duck embryos. These results showed that the weight of duckling livers increased with age from the embryonic period to the first week after hatching, and the hepatocytes that were cultured grew well. These were not only helpful to improving the understanding of liver development in vivo and hepatic cell cultures in vitro, but they also might further contribute to investigating lipid metabolism in ducks. ABSTRACT: The liver is the main site of fat synthesis and plays an important role in the study of fat deposition in poultry. In this study, we investigated the developmental changes of duckling livers and isolated primary duck hepatocytes. Firstly, we observed morphological changes in duckling livers from the embryonic period to the first week after hatching. Liver weight increased with age. Hematoxylin-eosin and Oil Red O staining analyses showed that hepatic lipids increased gradually during the embryonic period and declined post-hatching. Liver samples were collected from 21-day-old duck embryos for hepatocyte isolation. The hepatocytes showed limited self-renewal and proliferative ability and were maintained in culture for up to 7 days. Typical parenchymal morphology, with a characteristic polygonal shape, appeared after two days of culture. Periodic acid-Schiff (PAS) staining analysis confirmed the characteristics of duck embryo hepatocytes. PCR analysis showed that these cells from duck embryos expressed the liver cell markers ALB and CD36. Immunohistochemical staining and immunofluorescence analysis also confirmed ALB and CK18 expression. Our findings provide a novel insight regarding in vitro cell culture and the characteristics of hepatocytes from avian species, which could enable further studies concerning specific research on duck lipid metabolism.