E-GEOD-11073 - Gene expression profiles in liver of pigs with extreme high and low levels of androstenone.
Released on 17 August 2008, last updated on 1 May 2014
ABSTRACT: BACKGROUND: Boar taint is the unpleasant odour and flavour of the meat of uncastrated male pigs that is primarily caused by high levels of androstenone and skatole in adipose tissue. Androstenone is a steroid and its levels are mainly genetically determined. Studies on androstenone metabolism have, however, focused on a limited number of genes. Identification of additional genes influencing levels of androstenone may facilitate implementation of marker assisted breeding practices. In this study, microarrays were used to identify differentially expressed genes and pathways related to androstenone metabolism in the liver from boars with extreme levels of androstenone in adipose tissue. RESULTS: Liver tissue samples from 58 boars of the two breeds Duroc and Norwegian Landrace, 29 with extreme high and 29 with extreme low levels of androstenone, were selected from more than 2500 individuals. The samples were hybridised to porcine cDNA microarrays and the 1 % most significant differentially expressed genes were considered significant. Among the differentially expressed genes were metabolic phase I related genes belonging to the cytochrome P450 family and the flavin-containing monooxygenase FMO1. Additionally, phase II conjugation genes including UDP-glucuronosyltransferases UGT1A5, UGT2A1 and UGT2B15, sulfotransferase STE, N-acetyltransferase NAT12 and glutathione S-transferase were identified. Phase I and phase II metabolic reactions increase the water solubility of steroids and play a key role in their elimination. Differential expression was also found for genes encoding 17beta-hydroxysteroid dehydrogenases (HSD17B2, HSD17B4, HSD17B11 and HSD17B13) and plasma proteins alpha-1-acid glycoprotein (AGP) and orosomucoid (ORM1). 17beta-hydroxysteroid dehydrogenases and plasma proteins regulate the availability of steroids by controlling the amount of active steroids accessible to receptors and available for metabolism. Differences in the expression of FMO1, NAT12, HSD17B2 and HSD17B13 were verified by quantitative real competitive PCR. CONCLUSIONS: A number of genes and pathways related to metabolism of androstenone in liver were identified, including new candidate genes involved in phase I oxidation metabolism, phase II conjugation metabolism, and regulation of steroid availability. The study is a first step towards a deeper understanding of enzymes and regulators involved in pathways of androstenone metabolism and may ultimately lead to the discovery of markers to reduce boar taint. Liver samples from 116 animals with extreme androstenone values, 29 high and 29 low from each of the two breeds Norwegian Landrace and Duroc, were used for this experiment. Each sample was hybridised together with a common refrence resulting in a total of 116 microarrays.
transcription profiling by array
Jakob Hedegaard <Jakob.Hedegaard@ki.au.dk>, Christian Bendixen, Eli Grindflek, Henrik Hornshøj, Ingunn Berget, Maren Moe, Sigbjørn Lien, Theo Meuwissen
Gene expression profiles in liver of pigs with extreme high and low levels of androstenone. Moe M, Lien S, Bendixen C, Hedegaard J, Hornshøj H, Berget I, Meuwissen TH, Grindflek E. , Europe PMC 18684314