Abstract：This experiment is conducted to study the 3-hydroxy-3-methylglutaryl coenzyme A synthase gene (HMGCS1), to obtain the cDNA sequence， and to quest the correlation between HMGCS1 gene expression and cholesterol biosynthesis in the overfeeding goose liver. We selected landes goose(Anser anser) as experiment animal, which were needed for overfeeding 28 d. The experiments were designed to clone the whole cDNA of HMGCS1 gene by RT-PCR and RACE techniques and the expression of HMGCS1 in different tissues were analyzed by fluorescence quantitative RT-PCR. We choosed a cholesterol kit to detect the cholesterol level in goose liver. Finally we got nucleotide sequence of a full-length 2 947 bp cDNA for the HMG-CoA synthase, encoding a protein of 522 amino acids(GenBank accession No.KF425515). The results of RT-PCR showed that the gene expression in liver was extremely higher than that of other tissues(P＜0.05). After overfeeding for 28 d, the cholesterol in the liver decreased in the experiment group, but the decrease was not significant(P＞0.05). Nevertheless, there was a significant decrease in the level of HMGCS1 mRNA expression in experiment group(P＜0.05). The results of amino acid sequence analysis indicated that the gene maintained a high conservatism in evolution with ducks(Anas platyrhynchos), chickens(Gallus gallus) and pigeon(Columba livia). The gene was mainly expressed in the liver. There was a positive correlation between the cholesterol levels and the activity of the HMGCS1 in the cholesterol biosynthetic pathway. These results may provide the basic data for further research on the structure and functions of HMGCS1 gene.
