Abstract：Suppression subtractive hybridization was used to compare gene expression of middle versus late lactation of Xinong Saanen Goat mammary gland, and the goat butyrophilin(gBTN1A1) gene was screened form subtracted cDNA library of difference expressed genes. After electrical spilicing, The gBTN1A1 gene was amplified and cloned from total RNA of goat mammary gland by RT-PCR , and Registered in Genbank. Sequence analysis indicated that the gBTN1A1 complementary DNA that contained an open reading frame of 1581 nucleotides encoding a putative protein of 526 amino acids was identified. The whole DNA sequence includes 7 exons and 6 introns and amino acids through 1-26 constitute the signal peptide domain. The homologies of nucleotide and peptide sequence of the butyrophilin with bovine (NM_174508), human (NM_001732) and mouse’s (AK145168) are 97%, 88%, 84%，96%, 84% and 70%, respectively. The predicted structure of gBTN1A1 was similar to that of bovine and human, although some differences exist in transmembrane domain and hydrophilicity among them. Our results suggested that the goat mammary gland mRNA level of gBTN1A1 was not only responsible for milk fat globule secretion, but also for milk yield.
