Screening Of The Differentially Expressed Genes Related To The Formation Of Goose Fatty Liver By SSH

In present study, suppression subtractive hybridization (SSH) was used to detect differential expression of genes in the livers of overfeeding and normal feeding Landes geese. These differential expression bands were cloned, sequenced and aligned homology with known genes from the GenBank.And then, they were classified into functional categories and analyzed by Kyoto Encyclopaedia of Genes and Genomes (KEGG) automatic annotation server for ortholog assignment and pathway mapping, and the possible functions and schematic representation of the roles of the genes were predicted and drawn. Twelve genes that related to metabolism processes and cellular processes were confirmed using quantitative real time PCR (qRT-PCR). Four genes were selected and detected in different tissues and period of overfeeding. The serum biochemical parameters were measured during the period of overfeeding and tissue nutrient composition and histological changes in liver were also measured, results are as follows:(1) The concentration of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TG), total cholesterol (TC) and high density lipoprotein (HDL) in overfeeding Landes geese serum were significantly increased. Theγ-glutamyl transpeptidase (GGT) level was increased and then decreased during the overfeeding period. The tissue nutrient component analysis showed that fat was mainly deposited in liver, and the content of protein was increased in muscle and liver after overfeeding. Histology observation shown that liver cytoplasm was full of fat in overfeeding group. The results indicated that overfeeding has changed the liver lipid metabolism and serum component of geese. (2) One hundred and seven differential expression genes containing 16 unknown sequences and 26 hypothetical genes in the livers of overfeeding geese and normal feeding geese were detected by SSH, of which 83 were up-regulated and 24 were down-regulated. The functional categories showed that these genes were maily related to lipids metabolism process, ceculler process and signal transduction.(3) Tweleve different expression genes selected from SSH results confirmed by qRT-PCR, which indicated that SSH was an efficient way to screening different expression genes related to goose fatty liver.(4) KEGG analysis showed that most genes were associated with pathways related to metabolism or biosynthesis pathways, especially for the biosynthesis of fatty acids. The fatty acids and TG synthesis were enhanced and glycolysis was was reduced in response to overfeeding. Several genes such as stearoyl-CoA desaturase (delta-9-desaturase) (SCD), ELOVL family member 6 (Elovl-6), NADP+ dependent malic enzyme (NADP-ME) and long-chain acyl-CoA synthetase 1 (ACSL1) are involved in the biosynthesis of unsaturated fatty acids which play an important role in the formation of goose fatty liver.