Agouti signalling protein ( ASIP ) gene: molecular cloning, sequence characterisation and tissue distribution in domestic goose.

Agouti signalling protein (ASIP) is an endogenous antagonist of melanocortin-1 receptor (MC1R) and is involved in the regulation of pigmentation in mammals. The objective of this study was to identify and characterise the ASIP gene in domestic goose.The goose ASIP cDNA consisted of a 44-nucleotide 5ʹ-terminal untranslated region (UTR), a 390-nucleotide open-reading frame (ORF) and a 45-nucleotide 3ʹ-UTR. The length of goose ASIP genomic DNA was 6176 bp, including three coding exons and two introns.Bioinformatic analysis indicated that the ORF encodes a protein of 130 amino-acid residues with a molecular weight of 14.88 kDa and an isoelectric point of 9.73.Multiple sequence alignments and phylogenetic analysis showed that the amino-acid sequence of ASIP was conserved in vertebrates, especially in the avian species.RT-qPCR showed that the goose ASIP mRNA was differentially expressed in the pigment deposition tissues, including eye, foot, feather follicle, skin of the back, as well as in skin of the abdomen. The expression level of the ASIP gene in skin of the abdomen was higher than that in skin of the back.Those findings will contribute to further understanding the functions of the ASIP gene in geese plumage colouring. [ABSTRACT FROM AUTHOR]