cDNA Cloning of Vasoactice Intestinal Peptide Receptor-1 Gene (VIPR-1) and Its Expression Characteristics in Tissues of Black Muscovy Duck (Cairina moschata)
Abstract：Recent studies have already indicated that vasoactice intestinal peptide (VIP) is closely related to the habit of birds' nesting. In this study, we first cloned VIP receptor gene and analyzed its characteristics of expression in different tissues of muscovy duck. Reversed transcript PCR was used to clone vasoactice intestinal peptide receptor-1 (VIPR-1) gene from the hypothalamus of black muscovy ducks(Cairina moschata), the cDNA sequence of this gene consisted of 1 125 nucleotides, which coded 335 amino acids(GenBank accession No. JN625215). The sequence of VIPR-1 was highly conserved in avian species. The muscovy duck VIPR-1 shared 96% amino acid identity to that of chicken (Gallus gallus), turkey(Meleagris gallopavo), and quail(Coturnix japonica), while it shared only 70%~72% amino acid identing to that of some mammalians like human(Homo sapiens), mice(Mus musculus), pig(Sus scrofa) and cattle(Bos taurus). The significant differences were detected in levels of VIPR-1 expressed in the stage of egg-laying, incubating and out-of-lay (P<0.05) by Real-time PCR, and the highest expression level was in the stage of incubating, while the lowest was in out-of-lay. This finding indicated that expression level VIPR-1 was closely correlated with the reproduction stages. In addition, VIPR-1 mRNA was found to be expressed in the hypothalamus, pituitary and ovary of black muscovy ducks. The highest expression level of VIPR-1 was found in hypothalamus, while the lowest level was in ovaries (P<0.01). In summary, VIPR-1 gene is highly conservative, and its tissue-specific expression patterns imply that VIPR-1 gene is involved in the role of hypothalamus-pituitary-ovary axis in regulating the incubation of muscovy ducks.
