Abstract：Insulin induced gene 2 (INSIG2) plays an important role in regulating the biogenesis and metabolism of lipid, while the synthesis and metabolism of lipid in goat mammary gland is closely related to milk quality. In order to clarify the relationship between them and provide further scientific support to improve the goat dairy flavor, we used RT-PCR to clone INSIG2 from Xinong Saanen goat (Capra hircus) mammary gland total RNA and analyze its expression in ten tissues. The results showed that we got a sequence of 915 bp (GenBank accession No. JQ361767), including 678 bp of open reading frame, which encoded a protein of 225 amino acids with a predicted molecular weight of 24.8730 kD and pI 8.77. Nucleotides and amino acid (aa) sequences alignment showed that the nucleotides and aa of goat INSIG2 had the highest score similarity with bovine (Bos taurus) in GenBank. Protein structure analysis showed that INSIG2 contained six transmembrane helices; hydrophobicity analysis indicated that both N-terminal and C-terminal of the protein were hydrophilic; the genetic distance analysis showed that goat had the closest relationship with bovine, followed by pig(Sus scrofa). RT-qPCR was used to examine the mRNA expression of INSIG2 in ten tissues, and the result showed that INSIG2 was expressed in all 10 tissues, the lung had the highest expression of INSIG2, followed by muscle, there was moderate expression in mammary gland, and the minimal expression was in heart. The study of INSIG2 gene cloning and tissue expression analysis will provide a basis for function studies of the gene in goat mammary gland
