Melopsittacus undulatus strain:not collected | isolate:green base color and yellow-green body feathers,black or dark brown stripes on the head, neck and back, Medium body size Raw sequence reads

Blood glucose is essential for energy demand and overall health, primarily regulated by the glucagon receptor (GCGR) family, which is highly conserved among vertebrates. Compared to other vertebrates, birds exhibit relatively high blood glucose levels, but the underlying mechanisms remain unclear. Our study reveals that avian GCGR has evolved distinctively, displaying persistent constitutive Gs signaling activity. In Melopsittacus undulatus (budgerigar), GCGR is highly expressed in the liver and demonstrates pronounced constitutive activity.To investigate the regulatory mechanisms of hyperglycemia in birds, we used AAV-sh(muGCGR) to silence endogenous GCGR expression in the livers of adult male budgerigars (mu) via intravenous injection and performed single-nucleus RNA sequencing. We identified hepatocytes as the key cell type responsible for GCGR synthesis in budgerigars by comparing GCGR expression levels across species.Our findings demonstrate that avian GCGR plays a critical role in coordinating glucose metabolism in liver tissues, and its elevated expression may be a contributing factor to the high blood glucose levels observed in birds.