Association between Single Nucleotide Polymorphisms of Fatty Acid Synthase and Fat Deposition in the Liver of the Overfed Goose.

Goose fatty liver is one of the most delicious and popular foods in the world, but there is no reliable genetic marker for the early selection and breeding of geese with good liver-producing potential. In our study, one hundred and twenty-four 78-day-old Landes geese bred in Shunda Landes goose breeding farm, Jiutai, Jilin, China were selected randomly. The fatty livers were sampled each week after overfeeding during a three week period. Polymerase chain reaction-single strand conformation polymorphism and DNA sequencing were used to identify single nucleotide polymorphisms (SNPs) of fatty acid synthase (FAS), which is an important enzyme involved in the synthesis of fat under both physiological and pathological conditions. Least-squares correlation was established between these SNPs and fatty liver weight, abdominal fat weight, and intestinal fat weight of the overfed Landes geese, respectively. The results showed that fatty liver weight of geese with EF and FF genotypes (amplified by primer P1) was significantly higher than that of the EE genotype (p<0.05), and liver weight of CD and DD genotypes (amplified by primer P2) was significantly higher than that of the CC genotype (p<0.05). Different genotype combinations showed different liver weights, and from highest to lowest were ABDD, DDEF, DDFF, DDEE, ABEF, ABFF, AADD, and CDEF. Further analysis of DNA sequencing showed that there were two SNPs within the 5' promoter region the FAS gene. The geese of EF and FF genotypes carried a change of T to C, and the geese of CD and DD genotypes carried a change of A to G. The changes of the bases could potentially influence the binding of some transcription factors to this region as to regulate FAS gene. To our knowledge, this is the first report of SNPs found within the 5' promoter region of the Landes goose FAS gene, and our data will provide an insight for early selection of geese for liver production.