Preliminary Findings of Structure and Expression of Opioid Receptor Genes in a Peregrine Falcon (Falco peregrinus), a Snowy Owl (Bubo scandiacus), and a Blue-fronted Amazon Parrot (Amazona aestiva)

Abstract To further knowledge of the physiology of opioid receptors in birds, the structure and expression of the μ-, δ-, and κ-opioid receptor genes were studied in a peregrine falcon (Falco peregrinus), a snowy owl (Bubo scandiacus), and a blue-fronted Amazon parrot (Amazona aestiva). Tissue samples were obtained from birds that had been euthanatized for poor release prognosis or medical reasons. Samples were taken from the brain (telencephalon, thalamus, pituitary gland, cerebellum, pons, medulla oblongata, mesencephalon), the spinal cord and dorsal root ganglions, and plantar foot skin. Messenger RNA was recovered, and reverse transcription polymerase chain reaction (RT-PCR) was performed to generate complementary DNA (cDNA) sequences. Gene structures were documented by directly comparing cDNA sequences with recently published genomic sequences for the peregrine falcon and the blue-fronted Amazon parrot or by comparisons with genomic sequences of related species for the snowy owl. Structurally, the av...