Hepatic Lipogenesis in Broiler Chickens with Different Fat Deposition during Embryonic Development

Abstract

In order to identify the genes involved in the fatness variability, we studied the expression of several genes implicated in the hepatic lipid metabolism of broiler chickens with different fat deposition patterns during embryonic development. The mRNA expression of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME) and apolipoprotein B100 (apoB100) genes were determined using reverse transcriptase-polymerase chain reaction (RT-PCR). Samples of livers were collected from Arbor Acres (AA) and Sanhuang (SH) chickens on day 9, 14 and 19 of embryonic development as well as at hatching. This study showed that hepatic triglyceride (TG) level was found to increase suddenly during day 14 of embryonic development, to gradually increase thereafter, and to remain relatively constant at hatching. FAS gene expression in AA and SH broilers occurred prior to hatching and at hatching. The gene was expressed more in the former breed. ACC gene expression was observed beginning at the earlier development stage of days 9. No breed difference was observed in ME and apoB gene expression. This study indicated that the expression of lipogenic enzyme genes of the liver in broiler chickens exhibited scheduling during embryogenesis. The ACC gene started to express earlier than the FAS gene during embryonic development. This suggested that embryonic liver synthesized fatty acid, and breed difference was noticed prior to hatching.

Effects of In Ovo Administration of DHEA on Lipid Metabolism and Hepatic Lipogenetic Genes Expression in Broiler Chickens During Embryonic Development

“…In our published study, we suggested that expression of the key gene (FAS) in the liver was responsible for de novo synthesis of fatty acid prior to hatching and at hatching [46]. The rate of hepatic lipogenesis was decreased by approximately 70% in DHEA-treated mice [47].…”

“…However, DHEA significantly reduced the expression of all three genes, SREBP-1c, ACC and FAS at hatching. Our previous studies indicated that embryonic liver synthesized fatty acid prior to hatching or at hatching [46]. This suggested that by decreasing the expression of transcriptional regulator, DHEA altered the expression levels of various downstream genes that are involved in the synthesis of TG.…”

The contributions of hepatic de novo lipogenesis to the difference in body fat mass of genetically lean and fat duck breeds

“…In the present study, we focused on the expression pattern of lipogenic genes (Acc, fas and Dgat2) and the levels of enzyme amount (ACC, ELVOL and FAS) in the hepatic tissues between the PK ducks and the HW ducks. These selected genes and enzymes have been shown to play roles in controlling the key lipogenesis processes and have been well established as good indicators of DNL (Daval et al 2000;Yen et al 2005;Zhao et al 2007;Rosebrough et al 2008;Herault et al 2010;Strable and Ntambi 2010). Our results demonstrated that the expression of these genes and enzyme activities (or concentrations) showed no obvious changes in the two duck breeds, indicating that hepatic DNL may participate less in the fat mass difference.…”

Use of Comparative Proteomics to Identify Key Proteins Related to Hepatic Lipid Metabolism in Broiler Chickens: Evidence Accounting for Differential Fat Deposition Between Strains

“…Spots 1,2,3,4,5,6,7,13,15,16,17,23,24,25,28,29,30,31,32,33,35 and 36 displayed down-regulation in SH broiler chicken embryo liver, among which, spots 6, 7, 13, 15, 16, 17, 23, 24, 25, 33 and 36 showed a greater than three-fold difference in volume. The remainder of the 40 spots displayed up-regulation in SH broiler chicken embryo liver, and spots 8,9,11,12,18,20,21,22,34 and 39 showed a greater than three-fold difference in volume.…”

“…Thus, these two species of broiler chickens provide good models for the study of hepatic lipid metabolism differences. Zhao et al [8,9] reported that genes related to lipid metabolism, such as fatty acid synthetase (FAS), ACC and apolipoprotein B100 (ApoB100), display different mRNA expression profiles during embryonic liver development in the two lines. However, little information is available relative to liver protein expression in the pathways and mechanisms that contribute to adiposity variability in both lean and fat lines, especially in chicken embryos.…”