Abstract: The acetyl-CoA and malonyl-CoA transacylases region encoded exon 9-15 of goat FAS gene plays a central role in synthesis of short- and medium- chain fatty acids in goat milk. In the research, the mRNA from Xinong Saanen goat mammary gland on 28th day of lactation was isolated, and exon 9-15 of FAS gene in xinong saanen goat mammary gland and partial cDNA of 3’ end of exon 8 and 5’ end of exon 16 were amplified with RT-PCR using the mammary gland cDNA as the template by reverse transcription(GenBank accession no. DQ 915966), after sequencing we analyzed homology of sequence among species and speculated its function by bioinformatics. Sequencing of the fragments showed that the cDNA consisted of 1449 bp, and it contained 1338 bp exon 9-15 and 9 bp 3’ end of exon 8 and 52 bp 5’ end of exon 16, which encoded 483 amino acid including the 951 bp (454 nt-1404 nt) AT/MT domain；The homologies of nucleotide and amino acid sequence of exon 9-15 of Xinong Saanen goat mammary gland FAS gene with those of bovine (NM_001012669), human (NM_004104), rattus (NM_017332) and chicken (NM_205155) were 95%、85.7%、82.7%、73.2% and 92.9%、77.7%、82.3%、64.7% respectively; Compared with the other four species, an amino acid in exon 10 of goat FAS gene was absent.

Key words: Goat, Mammary gland, Fatty acid synthase gene, Exon 9-15