title: Pathway based analysis of genes and interactions influencing porcine testis samples from boars with divergent androstenone content in back fat.
abstract: One of the primary factors contributing to boar taint is the level of androstenone in porcine adipose tissues. A majority of the studies performed to identify candidate biomarkers for the synthesis of androstenone in testis tissues follow a reductionist approach, identifying and studying the effect of biomarkers individually. Although these studies provide detailed information on individual biomarkers, a global picture of changes in metabolic pathways that lead to the difference in androstenone synthesis is still missing. The aim of this work was to identify major pathways and interactions influencing steroid hormone synthesis and androstenone biosynthesis using an integrative approach to provide a bird's eye view of the factors causing difference in steroidogenesis and androstenone biosynthesis. For this purpose, we followed an analysis procedure merging together gene expression data from boars with divergent levels of androstenone and pathway mapping and interaction network retrieved from KEGG database. The interaction networks were weighted with Pearson correlation coefficients calculated from gene expression data and significant interactions and enriched pathways were identified based on these networks. The results show that 1,023 interactions were significant for high and low androstenone animals and that a total of 92 pathways were enriched for significant interactions. Although published articles show that a number of these enriched pathways were activated as a result of downstream signaling of steroid hormones, we speculate that the significant interactions in pathways such as glutathione metabolism, sphingolipid metabolism, fatty acid metabolism and significant interactions in cAMP-PKA/PKC signaling might be the key factors determining the difference in steroidogenesis and androstenone biosynthesis between boars with divergent androstenone levels in our study. The results and assumptions presented in this study are from an in-silico analysis done at the gene expression level and further laboratory experiments at genomic, proteomic or metabolomic level are necessary to validate these findings.
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany; Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Schloss Birlinghoven, Sankt Augustin, Germany.
authors.forename: Sudeep
authors.initials: S
authors.lastname: Sahadevan
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany; Department of Animal Production and Technology, Faculty of Animal Science, Bogor Agricultural University, Bogor, Indonesia.
authors.forename: Asep
authors.initials: A
authors.lastname: Gunawan
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany.
authors.forename: Ernst
authors.initials: E
authors.lastname: Tholen
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Große-Brinkhaus
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany.
authors.forename: Dawit
authors.initials: D
authors.lastname: Tesfaye
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Schellander
authors.affiliation: Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Schloss Birlinghoven, Sankt Augustin, Germany; Bonn-Aachen International Center for Information Technology (B-IT), Bonn, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hofmann-Apitius
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Erciyes University, Kayseri, Turkey.
authors.forename: Mehmet Ulas
authors.initials: MU
authors.lastname: Cinar
authors.affiliation: Institute of Animal Science, University of Bonn, Bonn, Germany.
authors.forename: Muhammad Jasim
authors.initials: MJ
authors.lastname: Uddin
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D050154:Adiposity; D000736:Androstenes / Q000378:metabolism*; D000818:Animals; D053898:Biosynthetic Pathways / Q000235:genetics; D053263:Gene Regulatory Networks; D008297:Male; D015398:Signal Transduction / Q000235:genetics*; D013552:Swine; D013737:Testis / Q000378:metabolism*
chemical_list: D000736:Androstenes