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Sigbjørn Lien - One of the best experts on this subject based on the ideXlab platform.
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exploiting whole genome sequence data to fine map and characterize candidate genes within a quantitative trait loci region affecting Androstenone on porcine chromosome 5
Animal Genetics, 2017Co-Authors: M Van Son, Eli Grindflek, Matthew Peter Kent, Rahul Agarwal, Harald Grove, Sigbjørn LienAbstract:Summary Male piglets are routinely castrated to eliminate boar taint. However, this treatment is undesirable, and alternative approaches, including genetic strategies to reduce boar taint, are demanded. Androstenone is one of the causative agents of boar taint, and a QTL region affecting this pheromone has previously been reported on SSC5: 22.6–24.8 Mb in Duroc. The QTL region is one of the few reported for Androstenone that does not simultaneously affect levels of other sex steroids. The main objective of this study was to fine map this QTL. Whole genome sequence data from 23 Norwegian Duroc boars were analyzed to detect new polymorphisms within the QTL region. A subset of 161 SNPs was genotyped in 834 Duroc sires and analyzed for association with Androstenone in adipose tissue and testosterone, estrone sulphate and 17β-estradiol in blood plasma. Our results revealed 100 SNPs significantly associated with Androstenone levels in fat (P < 0.001) with 94 of the SNPs being in strong linkage disequilibrium in the region 23.03–24.27 Mb. This haplotype block contains at least four positional candidate genes (HSD17B6, SDR9C7, RDH16 and STAT6) involved in Androstenone biosynthesis. No significant associations were found between any of the SNPs and levels of testosterone and estrogens, confirming previous findings. The amount of phenotypic variance explained by single SNPs within the haplotype block was as high as 5.4%. As the SNPs in this region significantly affect levels of Androstenone without affecting levels of other sex steroids, they are especially interesting as genetic markers for selection against boar taint.
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large scale genome wide association and ldla mapping study identifies qtls for boar taint and related sex steroids
BMC Genomics, 2011Co-Authors: Eli Grindflek, Sigbjørn Lien, Matthew Peter Kent, Hanne Hamland, Marianne H S Hansen, Maren Van Son, Theo He MeuwissenAbstract:Boar taint is observed in a high proportion of uncastrated male pigs and is characterized by an unpleasant odor/flavor in cooked meat, primarily caused by elevated levels of Androstenone and skatole. Androstenone is a steroid produced in the testis in parallel with biosynthesis of other sex steroids like testosterone and estrogens. This represents a challenge when performing selection against Androstenone in breeding programs, without simultaneously decreasing levels of other steroids. The aim of this study was to use high-density genome wide association (GWA) in combination with linkage disequilibrium-linkage analysis (LDLA) to identify quantitative trait loci (QTL) associated with boar taint compounds and related sex steroids in commercial Landrace (n = 1,251) and Duroc (n = 918) breeds. Altogether, 14 genome wide significant (GWS) QTL regions for Androstenone in subcutaneous fat were obtained from the LDLA study in Landrace and 14 GWS QTL regions in Duroc. LDLA analysis revealed that 7 of these QTL regions, located on SSC 1, 2, 3, 7 and 15, were obtained in both breeds. All 14 GWS Androstenone QTLs in Landrace are also affecting the estrogens at chromosome wise significance (CWS) or GWS levels, while in Duroc, 3 of the 14 QTLs affect Androstenone without affecting any of the estrogens. For skatole, 10 and 4 QTLs were GWS in the LDLA analysis for Landrace and Duroc respectively, with 4 of these detected in both breeds. The GWS QTLs for skatole obtained by LDLA are located at SSC 1, 5, 6, 7, 10, 11, 13 and 14. This is the first report applying the Porcine 60 K SNP array for simultaneous analysis of boar taint compounds and related sex hormones, using both GWA and LDLA approaches. Several QTLs are involved in regulation of Androstenone and skatole, and most of the QTLs for Androstenone are also affecting the levels of estrogens. Seven QTLs for Androstenone were detected in one breed and confirmed in the other, i.e. in an independent sample, although the majority of QTLs are breed specific. Most QTLs for skatole do not negatively affect other sex hormones and should be easier to implement into the breeding scheme.
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Revealing genetic relationships between compounds affecting boar taint and reproduction in pigs
Journal of animal science, 2011Co-Authors: Eli Grindflek, Matthew Peter Kent, Theodorus Meuwissen, T. Aasmundstad, Hanne Hamland, Marianne H S Hansen, Torfinn Nome, P. Torjesen, Sigbjørn LienAbstract:Boar taint is characterized by an unpleasant taste or odor in intact male pigs and is primarily attributed to increased concentrations of Androstenone and skatole and to a lesser extent by increased indole. The boar taint compounds skatole and indole are produced by gut bacteria, metabolized in the liver, and stored in the fat tissue. Androstenone, on the other hand, is synthesized in the testis along with testosterone and estrogens, which are known to be important factors affecting fertility. The main goal of this study was to investigate the relationship between genetic factors involved in the primary boar taint compounds in an attempt to discover ways to reduce boar taint without decreasing fertility-related compounds. Heritabilities and genetic correlations between traits were estimated for compounds related to boar taint (Androstenone, skatole, indole) and reproduction (testosterone, 17β-estradiol, and estrone sulfate). Heritabilities in the range of 0.47 to 0.67 were detected for Androstenone concentrations in both fat and plasma, whereas those for skatole and indole were slightly less (0.27 to 0.41). The genetic correlations between Androstenone in plasma and fat were extremely high (0.91 to 0.98) in Duroc and Landrace. In addition, genetic correlations between Androstenone (both plasma and fat) and the other sex steroids (estrone sulfate, 17β-estradiol, and testosterone) were very high, in the range of 0.80 to 0.95. Furthermore, a genome-wide association study (GWA) and a combined linkage disequilibrium and linkage analysis (LDLA) were conducted on 1,533 purebred Landrace and 1,027 purebred Duroc to find genome regions involved in genetic control of the boar taint compounds Androstenone, skatole, and indole, and sex hormones related to fertility traits. Up to 3,297 informative SNP markers were included for both breeds, including SNP from several boar taint candidate genes. From the GWA study, we found that altogether 27 regions were significant at a genome-wide level (P < 0.05) and an additional 7 regions were significant at a chromosomal level. From the LDLA study, 7 regions were significant on a genome-wide level and an additional 7 regions were significant at a chromosomal level. The most convincing associations were obtained in 6 regions affecting skatole and indole in fat on chromosomes 1, 2, 3, 7, 13, and 14, 1 region on chromosome 6 affecting Androstenone in plasma only, and 5 regions on chromosomes 3, 4, 13, and 15 affecting Androstenone, testosterone, and estrogens.
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Transcript profiling of candidate genes in testis of pigs exhibiting large differences in Androstenone levels
BMC Genetics, 2010Co-Authors: Eli Grindflek, Ingunn Berget, Maren Moe, Paul Oeth, Sigbjørn LienAbstract:Background Boar taint is an unpleasant odor and flavor of the meat and occurs in a high proportion of uncastrated male pigs. Androstenone, a steroid produced in testis and acting as a sex pheromone regulating reproductive function in female pigs, is one of the main compounds responsible for boar taint. The primary goal of the present investigation was to determine the differential gene expression of selected candidate genes related to levels of Androstenone in pigs. Results Altogether 2560 boars from the Norwegian Landrace and Duroc populations were included in this study. Testicle samples from the 192 boars with most extreme high or low levels of Androstenone in fat were used for RNA extraction, and 15 candidate genes were selected and analyzed by real-competitive PCR analysis. The genes Cytochrome P450 c17 ( CYP17A1 ), Steroidogenic acute regulatory protein ( STAR ), Aldo-keto reductase family 1 member C4 ( AKR1C4 ), Short-chain dehydrogenase/reductase family member 4 ( DHRS4 ), Ferritin light polypeptide ( FTL ), Sulfotransferase family 2A, dehydroepiandrosterone-preferring member 1 ( SULT2A1 ), Cytochrome P450 subfamily XIA polypeptide 1 ( CYP11A1 ), Cytochrome b5 ( CYB5A ), and 17-beta-Hydroxysteroid dehydrogenase IV ( HSD17B4 ) were all found to be significantly (P < 0.05) up-regulated in high Androstenone boars in both Duroc and Landrace. Furthermore, Cytochrome P450 c19A2 ( CYP19A2 ) was down-regulated and progesterone receptor membrane component 1 ( PGRMC1 ) was up-regulated in high-Androstenone Duroc boars only, while CYP21 was significantly down-regulated (2.5) in high-Androstenone Landrace only. The genes Nuclear Receptor co-activator 4 ( NCOA4 ), Sphingomyrlin phosphodiesterase 1 ( SMPD1 ) and 3β-hydroxysteroid dehydrogenase ( HSD3B ) were not significantly differentially expressed in any breeds. Additionally, association studies were performed for the genes with one or more detected SNPs. Association between SNP and Androstenone level was observed in CYB5A only, suggesting cis-regulation of the differential transcription in this gene. Conclusion A large pig material of highly extreme Androstenone levels is investigated. The current study contributes to the knowledge about which genes that is differentially expressed regard to the levels of Androstenone in pigs. Results in this paper suggest that several genes are important in the regulation of Androstenone level in boars and warrant further evaluation of the above mentioned candidate genes, including analyses in different breeds, identification of causal mutations and possible gene interactions.
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transcript profiling of candidate genes in testis of pigs exhibiting large differences in Androstenone levels
BMC Genetics, 2010Co-Authors: Eli Grindflek, Ingunn Berget, Maren Moe, Paul Oeth, Sigbjørn LienAbstract:Boar taint is an unpleasant odor and flavor of the meat and occurs in a high proportion of uncastrated male pigs. Androstenone, a steroid produced in testis and acting as a sex pheromone regulating reproductive function in female pigs, is one of the main compounds responsible for boar taint. The primary goal of the present investigation was to determine the differential gene expression of selected candidate genes related to levels of Androstenone in pigs. Altogether 2560 boars from the Norwegian Landrace and Duroc populations were included in this study. Testicle samples from the 192 boars with most extreme high or low levels of Androstenone in fat were used for RNA extraction, and 15 candidate genes were selected and analyzed by real-competitive PCR analysis. The genes Cytochrome P450 c17 (CYP17A1), Steroidogenic acute regulatory protein (STAR), Aldo-keto reductase family 1 member C4 (AKR1C4), Short-chain dehydrogenase/reductase family member 4 (DHRS4), Ferritin light polypeptide (FTL), Sulfotransferase family 2A, dehydroepiandrosterone-preferring member 1 (SULT2A1), Cytochrome P450 subfamily XIA polypeptide 1 (CYP11A1), Cytochrome b5 (CYB5A), and 17-beta-Hydroxysteroid dehydrogenase IV (HSD17B4) were all found to be significantly (P < 0.05) up-regulated in high Androstenone boars in both Duroc and Landrace. Furthermore, Cytochrome P450 c19A2 (CYP19A2) was down-regulated and progesterone receptor membrane component 1 (PGRMC1) was up-regulated in high-Androstenone Duroc boars only, while CYP21 was significantly down-regulated (2.5) in high-Androstenone Landrace only. The genes Nuclear Receptor co-activator 4 (NCOA4), Sphingomyrlin phosphodiesterase 1 (SMPD1) and 3β-hydroxysteroid dehydrogenase (HSD3B) were not significantly differentially expressed in any breeds. Additionally, association studies were performed for the genes with one or more detected SNPs. Association between SNP and Androstenone level was observed in CYB5A only, suggesting cis-regulation of the differential transcription in this gene. A large pig material of highly extreme Androstenone levels is investigated. The current study contributes to the knowledge about which genes that is differentially expressed regard to the levels of Androstenone in pigs. Results in this paper suggest that several genes are important in the regulation of Androstenone level in boars and warrant further evaluation of the above mentioned candidate genes, including analyses in different breeds, identification of causal mutations and possible gene interactions.
Michel Bonneau - One of the best experts on this subject based on the ideXlab platform.
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Urinary signature of pig carcasses with boar taint by liquid chromatography-high resolution mass spectrometry
Food additives & contaminants. Part A. Chemistry analysis control exposure & risk assessment, 2017Co-Authors: Cristina C. Jacob, Michel Bonneau, Gaud Dervilly-pinel, Yoann Deceuninck, Audrey Gicquiau, Patrick Chevillon, Bruno Le BizecAbstract:Boar taint is an offensive odor that can occur while cooking pork or pork products and is identified in some uncastrated male pigs that have reached puberty. It is widely held that boar taint is the result of the accumulation in back-fat of two malodorous compounds: Androstenone and skatole. The purpose of the present study was to assess a mass spectrometry-based metabolomics strategy to investigate the metabolic profile of urine samples from pig carcasses presenting low (untainted) and high (tainted) levels of Androstenone and skatole in back fat. Urine samples were analyzed by LC-ESI(+)-HRMS. Discrimination between tainted and untainted animals was observed by application of multivariate statistical analysis, which allowed to highlight candidate urinary biomarkers. These urinary metabolites were positively correlated to Androstenone and skatole levels in back fat. Therefore, the present study suggested that the measurement of these urinary metabolites might provide information with regard to Androstenone and skatole levels in live pigs.
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Urinary signature of pig carcasses with boar taint by liquid chromatography-high-resolution mass spectrometry
2016Co-Authors: Cristina C. Jacob, Michel Bonneau, Gaud Dervilly-pinel, Yoann Deceuninck, Audrey Gicquiau, Patrick Chevillon, Bruno Le BizecAbstract:Boar taint is an offensive odour that can occur while cooking pork or pork products and is identified in some uncastrated male pigs that have reached puberty. It is widely held that boar taint is the result of the accumulation in back fat of two malodorous compounds: Androstenone and skatole. The purpose of this study is to assess a mass spectrometry-based metabolomics strategy to investigate the metabolic profile of urine samples from pig carcasses presenting low (untainted) and high (tainted) levels of Androstenone and skatole in back fat. Urine samples were analysed by LC-ESI(+)-HRMS. Discrimination between tainted and untainted animals was observed by the application of multivariate statistical analysis, which allowed candidate urinary biomarkers to be highlighted. These urinary metabolites were positively correlated to Androstenone and skatole levels in back fat. Therefore, the study suggests that the measurement of these urinary metabolites might provide information with regard to Androstenone and skatole levels in live pigs.
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Acceptability of entire male pork with various levels of Androstenone and skatole by consumers according to their sensitivity to Androstenone.
Meat Science, 2012Co-Authors: Michel Bonneau, P. ChevillonAbstract:Consumer acceptability of entire male pork at eating was assessed in three experiments. The 140 consumers involved in each experiment were classified as insensitive (INSENS) to the odor of pure Androstenone or sensitive perceiving it as pleasant (SENS-PLEA) or unpleasant (SENS-UNPL). Entire male pork with very low skatole and Androstenone levels (LS-LA) was as well accepted as gilt pork, whatever the consumer category. Entire male pork with elevated levels in both skatole and Androstenone (HS-HA) was clearly differentiated from LS-LA pork by SENS-UNPL, but not by SENS-PLEA or INSENS consumers. Whatever the consumer category, entire male pork with elevated levels of Androstenone and very low levels of skatole (LS-HA and LS-HHA) were not significantly differentiated from LS-LA pork. The results suggest that, in the conditions of the present experiment, Androstenone and skatole totally explain boar taint at eating and that the acceptability threshold for Androstenone, in the absence of skatole, is in the range of 2-3 μg/g liquid fat.
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genetic and metabolic aspects of Androstenone and skatole deposition in pig adipose tissue a review open access publication
Genetics Selection Evolution, 2008Co-Authors: A Robic, Catherine Larzul, Michel BonneauAbstract:High levels of Androstenone and skatole in fat tissues are considered the primary causes of boar taint, an unpleasant odour and flavour of the meat from non-castrated male pigs. The aim of this article is to review our current knowledge of the biology and genetic control of the accumulation of Androstenone and skatole in fat tissue. Two QTL mapping studies have shown the complexity of the genetic control of these traits. During the last ten years, several authors have taken a more physiological approach to investigate the involvement of genes controlling the metabolism of Androstenone and skatole. Although some authors have claimed the identification of candidate genes, it is more appropriate to talk about target genes. This suggests that genes affecting Androstenone and skatole levels will have to be sought for among specific or non-specific transcription factors interacting with these target genes.
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Genetic and metabolic aspects of Androstenone and skatole deposition in pig adipose tissue: A review
Genetics Selection Evolution, 2008Co-Authors: Annie Robic, Catherine Larzul, Michel BonneauAbstract:High levels of Androstenone and skatole in fat tissues are considered the primary causes of boar taint, an unpleasant odour and flavour of the meat from non-castrated male pigs. The aim of this article is to review our current knowledge of the biology and genetic control of the accumulation of Androstenone and skatole in fat tissue. Two QTL mapping studies have shown the complexity of the genetic control of these traits. During the last ten years, several authors have taken a more physiological approach to investigate the involvement of genes controlling the metabolism of Androstenone and skatole. Although some authors have claimed the identification of candidate genes, it is more appropriate to talk about target genes. This suggests that genes affecting Androstenone and skatole levels will have to be sought for among specific or non-specific transcription factors interacting with these target genes.
Eli Grindflek - One of the best experts on this subject based on the ideXlab platform.
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exploiting whole genome sequence data to fine map and characterize candidate genes within a quantitative trait loci region affecting Androstenone on porcine chromosome 5
Animal Genetics, 2017Co-Authors: M Van Son, Eli Grindflek, Matthew Peter Kent, Rahul Agarwal, Harald Grove, Sigbjørn LienAbstract:Summary Male piglets are routinely castrated to eliminate boar taint. However, this treatment is undesirable, and alternative approaches, including genetic strategies to reduce boar taint, are demanded. Androstenone is one of the causative agents of boar taint, and a QTL region affecting this pheromone has previously been reported on SSC5: 22.6–24.8 Mb in Duroc. The QTL region is one of the few reported for Androstenone that does not simultaneously affect levels of other sex steroids. The main objective of this study was to fine map this QTL. Whole genome sequence data from 23 Norwegian Duroc boars were analyzed to detect new polymorphisms within the QTL region. A subset of 161 SNPs was genotyped in 834 Duroc sires and analyzed for association with Androstenone in adipose tissue and testosterone, estrone sulphate and 17β-estradiol in blood plasma. Our results revealed 100 SNPs significantly associated with Androstenone levels in fat (P < 0.001) with 94 of the SNPs being in strong linkage disequilibrium in the region 23.03–24.27 Mb. This haplotype block contains at least four positional candidate genes (HSD17B6, SDR9C7, RDH16 and STAT6) involved in Androstenone biosynthesis. No significant associations were found between any of the SNPs and levels of testosterone and estrogens, confirming previous findings. The amount of phenotypic variance explained by single SNPs within the haplotype block was as high as 5.4%. As the SNPs in this region significantly affect levels of Androstenone without affecting levels of other sex steroids, they are especially interesting as genetic markers for selection against boar taint.
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large scale genome wide association and ldla mapping study identifies qtls for boar taint and related sex steroids
BMC Genomics, 2011Co-Authors: Eli Grindflek, Sigbjørn Lien, Matthew Peter Kent, Hanne Hamland, Marianne H S Hansen, Maren Van Son, Theo He MeuwissenAbstract:Boar taint is observed in a high proportion of uncastrated male pigs and is characterized by an unpleasant odor/flavor in cooked meat, primarily caused by elevated levels of Androstenone and skatole. Androstenone is a steroid produced in the testis in parallel with biosynthesis of other sex steroids like testosterone and estrogens. This represents a challenge when performing selection against Androstenone in breeding programs, without simultaneously decreasing levels of other steroids. The aim of this study was to use high-density genome wide association (GWA) in combination with linkage disequilibrium-linkage analysis (LDLA) to identify quantitative trait loci (QTL) associated with boar taint compounds and related sex steroids in commercial Landrace (n = 1,251) and Duroc (n = 918) breeds. Altogether, 14 genome wide significant (GWS) QTL regions for Androstenone in subcutaneous fat were obtained from the LDLA study in Landrace and 14 GWS QTL regions in Duroc. LDLA analysis revealed that 7 of these QTL regions, located on SSC 1, 2, 3, 7 and 15, were obtained in both breeds. All 14 GWS Androstenone QTLs in Landrace are also affecting the estrogens at chromosome wise significance (CWS) or GWS levels, while in Duroc, 3 of the 14 QTLs affect Androstenone without affecting any of the estrogens. For skatole, 10 and 4 QTLs were GWS in the LDLA analysis for Landrace and Duroc respectively, with 4 of these detected in both breeds. The GWS QTLs for skatole obtained by LDLA are located at SSC 1, 5, 6, 7, 10, 11, 13 and 14. This is the first report applying the Porcine 60 K SNP array for simultaneous analysis of boar taint compounds and related sex hormones, using both GWA and LDLA approaches. Several QTLs are involved in regulation of Androstenone and skatole, and most of the QTLs for Androstenone are also affecting the levels of estrogens. Seven QTLs for Androstenone were detected in one breed and confirmed in the other, i.e. in an independent sample, although the majority of QTLs are breed specific. Most QTLs for skatole do not negatively affect other sex hormones and should be easier to implement into the breeding scheme.
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Revealing genetic relationships between compounds affecting boar taint and reproduction in pigs
Journal of animal science, 2011Co-Authors: Eli Grindflek, Matthew Peter Kent, Theodorus Meuwissen, T. Aasmundstad, Hanne Hamland, Marianne H S Hansen, Torfinn Nome, P. Torjesen, Sigbjørn LienAbstract:Boar taint is characterized by an unpleasant taste or odor in intact male pigs and is primarily attributed to increased concentrations of Androstenone and skatole and to a lesser extent by increased indole. The boar taint compounds skatole and indole are produced by gut bacteria, metabolized in the liver, and stored in the fat tissue. Androstenone, on the other hand, is synthesized in the testis along with testosterone and estrogens, which are known to be important factors affecting fertility. The main goal of this study was to investigate the relationship between genetic factors involved in the primary boar taint compounds in an attempt to discover ways to reduce boar taint without decreasing fertility-related compounds. Heritabilities and genetic correlations between traits were estimated for compounds related to boar taint (Androstenone, skatole, indole) and reproduction (testosterone, 17β-estradiol, and estrone sulfate). Heritabilities in the range of 0.47 to 0.67 were detected for Androstenone concentrations in both fat and plasma, whereas those for skatole and indole were slightly less (0.27 to 0.41). The genetic correlations between Androstenone in plasma and fat were extremely high (0.91 to 0.98) in Duroc and Landrace. In addition, genetic correlations between Androstenone (both plasma and fat) and the other sex steroids (estrone sulfate, 17β-estradiol, and testosterone) were very high, in the range of 0.80 to 0.95. Furthermore, a genome-wide association study (GWA) and a combined linkage disequilibrium and linkage analysis (LDLA) were conducted on 1,533 purebred Landrace and 1,027 purebred Duroc to find genome regions involved in genetic control of the boar taint compounds Androstenone, skatole, and indole, and sex hormones related to fertility traits. Up to 3,297 informative SNP markers were included for both breeds, including SNP from several boar taint candidate genes. From the GWA study, we found that altogether 27 regions were significant at a genome-wide level (P < 0.05) and an additional 7 regions were significant at a chromosomal level. From the LDLA study, 7 regions were significant on a genome-wide level and an additional 7 regions were significant at a chromosomal level. The most convincing associations were obtained in 6 regions affecting skatole and indole in fat on chromosomes 1, 2, 3, 7, 13, and 14, 1 region on chromosome 6 affecting Androstenone in plasma only, and 5 regions on chromosomes 3, 4, 13, and 15 affecting Androstenone, testosterone, and estrogens.
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Transcript profiling of candidate genes in testis of pigs exhibiting large differences in Androstenone levels
BMC Genetics, 2010Co-Authors: Eli Grindflek, Ingunn Berget, Maren Moe, Paul Oeth, Sigbjørn LienAbstract:Background Boar taint is an unpleasant odor and flavor of the meat and occurs in a high proportion of uncastrated male pigs. Androstenone, a steroid produced in testis and acting as a sex pheromone regulating reproductive function in female pigs, is one of the main compounds responsible for boar taint. The primary goal of the present investigation was to determine the differential gene expression of selected candidate genes related to levels of Androstenone in pigs. Results Altogether 2560 boars from the Norwegian Landrace and Duroc populations were included in this study. Testicle samples from the 192 boars with most extreme high or low levels of Androstenone in fat were used for RNA extraction, and 15 candidate genes were selected and analyzed by real-competitive PCR analysis. The genes Cytochrome P450 c17 ( CYP17A1 ), Steroidogenic acute regulatory protein ( STAR ), Aldo-keto reductase family 1 member C4 ( AKR1C4 ), Short-chain dehydrogenase/reductase family member 4 ( DHRS4 ), Ferritin light polypeptide ( FTL ), Sulfotransferase family 2A, dehydroepiandrosterone-preferring member 1 ( SULT2A1 ), Cytochrome P450 subfamily XIA polypeptide 1 ( CYP11A1 ), Cytochrome b5 ( CYB5A ), and 17-beta-Hydroxysteroid dehydrogenase IV ( HSD17B4 ) were all found to be significantly (P < 0.05) up-regulated in high Androstenone boars in both Duroc and Landrace. Furthermore, Cytochrome P450 c19A2 ( CYP19A2 ) was down-regulated and progesterone receptor membrane component 1 ( PGRMC1 ) was up-regulated in high-Androstenone Duroc boars only, while CYP21 was significantly down-regulated (2.5) in high-Androstenone Landrace only. The genes Nuclear Receptor co-activator 4 ( NCOA4 ), Sphingomyrlin phosphodiesterase 1 ( SMPD1 ) and 3β-hydroxysteroid dehydrogenase ( HSD3B ) were not significantly differentially expressed in any breeds. Additionally, association studies were performed for the genes with one or more detected SNPs. Association between SNP and Androstenone level was observed in CYB5A only, suggesting cis-regulation of the differential transcription in this gene. Conclusion A large pig material of highly extreme Androstenone levels is investigated. The current study contributes to the knowledge about which genes that is differentially expressed regard to the levels of Androstenone in pigs. Results in this paper suggest that several genes are important in the regulation of Androstenone level in boars and warrant further evaluation of the above mentioned candidate genes, including analyses in different breeds, identification of causal mutations and possible gene interactions.
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transcript profiling of candidate genes in testis of pigs exhibiting large differences in Androstenone levels
BMC Genetics, 2010Co-Authors: Eli Grindflek, Ingunn Berget, Maren Moe, Paul Oeth, Sigbjørn LienAbstract:Boar taint is an unpleasant odor and flavor of the meat and occurs in a high proportion of uncastrated male pigs. Androstenone, a steroid produced in testis and acting as a sex pheromone regulating reproductive function in female pigs, is one of the main compounds responsible for boar taint. The primary goal of the present investigation was to determine the differential gene expression of selected candidate genes related to levels of Androstenone in pigs. Altogether 2560 boars from the Norwegian Landrace and Duroc populations were included in this study. Testicle samples from the 192 boars with most extreme high or low levels of Androstenone in fat were used for RNA extraction, and 15 candidate genes were selected and analyzed by real-competitive PCR analysis. The genes Cytochrome P450 c17 (CYP17A1), Steroidogenic acute regulatory protein (STAR), Aldo-keto reductase family 1 member C4 (AKR1C4), Short-chain dehydrogenase/reductase family member 4 (DHRS4), Ferritin light polypeptide (FTL), Sulfotransferase family 2A, dehydroepiandrosterone-preferring member 1 (SULT2A1), Cytochrome P450 subfamily XIA polypeptide 1 (CYP11A1), Cytochrome b5 (CYB5A), and 17-beta-Hydroxysteroid dehydrogenase IV (HSD17B4) were all found to be significantly (P < 0.05) up-regulated in high Androstenone boars in both Duroc and Landrace. Furthermore, Cytochrome P450 c19A2 (CYP19A2) was down-regulated and progesterone receptor membrane component 1 (PGRMC1) was up-regulated in high-Androstenone Duroc boars only, while CYP21 was significantly down-regulated (2.5) in high-Androstenone Landrace only. The genes Nuclear Receptor co-activator 4 (NCOA4), Sphingomyrlin phosphodiesterase 1 (SMPD1) and 3β-hydroxysteroid dehydrogenase (HSD3B) were not significantly differentially expressed in any breeds. Additionally, association studies were performed for the genes with one or more detected SNPs. Association between SNP and Androstenone level was observed in CYB5A only, suggesting cis-regulation of the differential transcription in this gene. A large pig material of highly extreme Androstenone levels is investigated. The current study contributes to the knowledge about which genes that is differentially expressed regard to the levels of Androstenone in pigs. Results in this paper suggest that several genes are important in the regulation of Androstenone level in boars and warrant further evaluation of the above mentioned candidate genes, including analyses in different breeds, identification of causal mutations and possible gene interactions.
J. D. Wood - One of the best experts on this subject based on the ideXlab platform.
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comparison of heating methods and the use of different tissues for sensory assessment of abnormal odours boar taint in pig meat
Meat Science, 2011Co-Authors: F. M. Whittington, G.r. Nute, Si Hughes, D Zammerini, A Baker, J. D. WoodAbstract:Five heating methods (microwave, hotwire, boiling at 25 °C and 75 °C and melting) were used to generate cooking odours from backfat of entire male pigs and a 'composite' sample consisting of fat and muscle from the head along with salivary glands. The methods elicited significantly different scores for odours from 4 groups of 10 samples differing in their concentrations and ratios of skatole and Androstenone. The odours (pork odour, abnormal odour, skatole odour and Androstenone odour) were assessed by 3 experienced assessors. Correlations between skatole and Androstenone concentrations and abnormal odour score in backfat were higher for skatole, suggesting it is the more important boar taint compound. In the composite sample, Androstenone concentration was much higher than in backfat and Androstenone was a more important contributor to boar taint. The microwave, hotwire and boiling (75 °C) methods produced the clearest separation between samples and the microwave method was considered the most suitable for on-line use.
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Relationship between the expression of hepatic but not testicular 3β-hydroxysteroid dehydrogenase with Androstenone deposition in pig adipose tissue
Journal of animal science, 2006Co-Authors: S. I. Nicolau-solano, J. D. Wood, J.d. Mcgivan, F. M. Whittington, G. J. Nieuwhof, Olena DoranAbstract:ABSTRACT: This study investigated the relationship between expression of hepatic and testicular 3β- hydroxysteroid dehydrogenase (3β-HSD) and accumulation of Androstenone in adipose tissue because of its relation to boar taint. The experiments were performed on 13 Large White (50%) × Landrace (50%) and Meishan (25%) × Large White (25%) × Landrace (50%), pigs, which differed in the level of backfat Androstenone. Our previous work showed that the major product of the hepatic Androstenone metabolism is 3β-androstenol. In this study, the formation of 3β-androstenol was inhibited by the specific 3β-HSD inhibitor trilostane. These results are the first direct confirmation that 3β-HSD is the enzyme responsible for Androstenone metabolism in the pig. The expression of the hepatic but not testicular 3β-HSD protein showed a negative relationship with the level of backfat Androstenone (r2 = 0.64; P < 0.001) and was accompanied by a reduced rate of the hepatic Androstenone clearance. Low expression of 3β-HSD pro-tein in the liver of high Androstenone pigs was also accompanied by a reduced level of 3β-HSD mRNA (P < 0.001), which suggests a defective regulation of the hepatic 3β-HSD expression at the level of transcription. In contrast, expression of the testicular 3β-HSD protein did not differ between animals with high and low Androstenone levels (P > 0.05) and was lower compared with the hepatic 3β-HSD expression. Cloning and sequencing of the 3β-HSD coding regions established that the hepatic and testicular 3β-HSD cDNA have identical sequences, which were 98% similar to the human 3β- HSDisoform I. It is suggested that expression of a single 3β-HSD gene is regulated by different mechanisms in pig liver and testis. The liver-specific regulation of 3β- HSD expression contributes to the low rate of hepatic Androstenone metabolism and therefore can be considered as one of the factors regulating deposition of Androstenone in pig adipose tissue and subsequent development of boar taint.
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relationships between skatole and Androstenone accumulation and cytochrome p4502e1 expression in meishan large white pigs
Meat Science, 2004Co-Authors: F. M. Whittington, G.r. Nute, J. D. Wood, J.d. Mcgivan, Si Hughes, I. J. Lean, Elena DoranAbstract:The effects of age, castration and diet on accumulation of skatole and Androstenone in the backfat of 50% Meishan male pigs, was studied in relation to boar taint. Skatole and Androstenone deposition in backfat of entire males was increased with age (114, 144 and 174 days). Castration significantly decreased skatole and Androstenone levels in all age groups. The level of cytochrome P4502E1, the initial enzyme involved in hepatic skatole metabolism, was increased by castration at all ages. These results suggest that the decrease in Androstenone levels following castration affects the regulation of cytochrome P4502E1 expression, and as a consequence, results in a decrease in skatole levels. The use of sugar beet feed in the diet decreased the level of skatole and increased that of cytochrome P4502E1 expression, but did not affect Androstenone levels. It is suggested that skatole accumulation is reduced both by castration and by diet via induction of cytochrome P4502E1. However, the mechanism of induction of cytochrome P4502E1 by diet is different from that involved in its induction by castration.
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Characterisation of Androstenone metabolism in pig liver microsomes.
Chemico-biological interactions, 2004Co-Authors: Elena Doran, J. D. Wood, F. M. Whittington, J.d. McgivanAbstract:Androstenone (5 alpha-androst-16-en-3-one) is a steroid pheromone produced in the testis. Excessive accumulation of Androstenone together with skatole (3-methyl-indole) in the adipose tissue of some male pigs leads to "boar taint". In isolated pig hepatocytes Androstenone represses the expression of cytochrome P450IIE1 (CYP2E1), the enzyme principally responsible for skatole metabolism. Androstenone can be metabolised in liver microsomes but the pathway has not been established. We have investigated Androstenone metabolism in liver microsomes from two breeds of pigs exhibiting low and high levels of Androstenone in adipose tissue-Large White (LW) and Meishan (M), respectively. Androstenone was reduced in isolated liver microsomes mainly to beta-androstenol using NADH as a co-factor. The rate of beta-androstenol formation in the presence of NADPH was very low. In microsomes from LW pigs the rate of beta-androstenol formation from Androstenone was six times higher than in M pigs. 3beta-hydroxysteroid dehydrogenase (3beta-HSD) was investigated as a likely candidate for the enzyme catalysing Androstenone reduction in pig liver. RT-PCR analysis showed that there was no sequence difference in the cDNA encoding 3beta-hydroxysteroid dehydrogenase from LW and M pigs. However, competitive RT-PCR analysis showed that the expression of 3beta-hydroxysteroid dehydrogenase mRNA was about 12 times higher in the case of LW compared to M pigs. It is concluded that the rate of Androstenone metabolism in pig liver microsomes is determined by the level of expression of hepatic 3beta-hydroxysteroid dehydrogenase. The differential expression of this enzyme could be a factor affecting the rate of hepatic Androstenone metabolism which in turn may influence the level of hepatic CYP2E1 expression and hence the rate of hepatic skatole metabolism.
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the problem of taint in pork ii the influence of skatole Androstenone and indole presented individually and in combination in a model lipid base on odour perception
Meat Science, 1997Co-Authors: G.r. Nute, F.w. Whittington, I E Annorfrempong, J. D. WoodAbstract:Abstract Responses to varying concentrations of Androstenone and skatole in a neutral lipid base were studied using a trained 10-member panel. Concentrations for skatole and Androstenone ranged between 0–1.32 and 0–6.0 μg g −1 , respectively. Odour, Androstenone and skatole intensities were assessed by the line scaling method. Triangular tests showed that the panel significantly distinguished indole from Androstenone, p ≤ 0.01, but not from skatole nor mixtures of Androstenone and skatole. Regression analyses showed linear relationships between skatole and Androstenone concentrations and odour intensity but with a significant ( p ≤ 0.01) Androstenone-assessor interaction. Correlation coefficients with odour intensity were 0.64 and 0.63 for Androstenone and skatole concentrations, respectively. Response surface curves showed that odour intensity depended on the linear terms of skatole, Androstenone and on the quadratic term of Androstenone. Androstenone and skatole intensity ratings revealed that the effect of skatole was enhanced by the presence of Androstenone, but not the reverse. It was concluded that whilst both Androstenone and skatole may be important for the sorting (classification) of pork, the importance of Androstenone lies in its detection threshold whilst for skatole, the acceptability threshold may be a suitable criterion for quality control purposes.
Galia Zamaratskaia - One of the best experts on this subject based on the ideXlab platform.
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Chestnut wood extract in boar diet reduces intestinal skatole production, a boar taint compound
Agronomy for Sustainable Development, 2016Co-Authors: Diana Bilić-Šobot, Maja Prevolnik Povše, Martin Kroyer Rasmussen, Martin Škrlep, Marjeta Čandek-potokar, Galia Zamaratskaia, Dejan ŠkorjancAbstract:Abandoning traditional practice of piglet castration will impact the pigmeat sector. As a consequence, there is a need for research aiming at reducing boar taint caused by Androstenone and skatole. Skatole is metabolized by cytochrome P450 enzymes (CYP450) in the liver. Skatole hepatic clearance is believed to be hindered by Androstenone. Diet ingredients may modify skatole metabolism. Therefore, we tested the effect of hydrolysable tannins. We fed 51 young boars with 1–3 % chestnut wood extract as supplementary diet. After slaughter, the tissues were collected to assess Androstenone and skatole accumulation in fat and to measure CYP450 activities, gene, and protein expression in the liver and intestine. Protein expression of two enzymes involved in Androstenone metabolism, 3-beta-hydroxysteroid dehydrogenase (3β-HSD) and sulfotransferase family 2A member 1 (SULT2A1), was assessed, and feces collected to evaluate skatole production. Results show that intestinal skatole production in boars supplemented with 3 % of chestnut wood extract was more than halved. The intestinal catalytic activities of CYP450 were tenfold lower than hepatic and were mainly unaffected by tannins. Findings indicate a potential effect of tannins on steroidogenesis, which in the absence of effect on 3β-HSD and SULT2A1 expression suggests lower synthesis of Androstenone due to tannins.
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investigation of testosterone Androstenone and estradiol metabolism in hepg2 cells and primary culture pig hepatocytes and their effects on 17βhsd7 gene expression
PLOS ONE, 2012Co-Authors: Gang Chen, Galia Zamaratskaia, Shuming Yang, Xinxing Dong, Ying Bai, Ailiang Chen, Meiying Fang, Olena DoranAbstract:Steroid metabolism is important in various species. The accumulation of androgen metabolite, Androstenone, in pig adipose tissue is negatively associated with pork flavor, odour and makes the meat unfit for human consumption. The 17β-hydroxysteroid dehydrogenase type 7 (17βHSD7) expressed abundantly in porcine liver, and it was previously suggested to be associated with Androstenone levels. Understanding the enzymes and metabolic pathways responsible for Androstenone as well as other steroids metabolism is important for improving the meat quality. At the same time, metabolism of steroids is known to be species- and tissue-specific. Therefore it is important to investigate between-species variations in the hepatic steroid metabolism and to elucidate the role of 17βHSD7 in this process. Here we used an effective methodological approach, liquid chromatography coupled with mass spectrometry, to investigate species-specific metabolism of Androstenone, testosterone and beta-estradiol in HepG2 cell line, and pig cultured hepatocytes. Species- and concentration-depended effect of steroids on 17βHSD7 gene expression was also investigated. It was demonstrated that the investigated steroids can regulate the 17βHSD7 gene expression in HepG2 and primary cultured porcine hepatocytes in a concentration-dependent and species-dependent pattern. Investigation of steroid metabolites demonstrated that Androstenone formed a 3′-hydroxy compound 3β-hydroxy-5α-androst-16-ene. Testosterone was metabolized to 4-androstene-3,17-dione. Estrone was found as the metabolite for β-estradiol. Inhibition study with 17βHSD inhibitor apigenin showed that apigenin didn’t affect Androstenone metabolism. Apigenin at high concentration (50 µM) tends to inhibit testosterone metabolism but this inhibition effect was negligible. Beta-estradiol metabolism was notably inhibited with apigenin at high concentration. The study also established that the level of testosterone and β-estradiol metabolites was markedly increased after co-incubation with high concentration of apigenin. This study established that 17βHSD7 is not the key enzyme responsible for Androstenone and testosterone metabolism in porcine liver cells.
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effect of polymorphism in the porcine cytochrome b5 cyb5a gene on Androstenone and skatole concentrations and sexual development in swedish pig populations
Animal, 2008Co-Authors: Galia Zamaratskaia, K Lundstrom, G Chen, H K Andersson, Y Lou, J Peacock, L Rydhmer, R K Juneja, E. J. SquiresAbstract:The present study investigated the presence of a single-nucleotide polymorphism (G > T) at base -8 upstream of ATG in 5' untranslated region of cytochrome b5 (CYB5A) gene in Swedish pig populations and evaluated the significance of this polymorphism for Androstenone and skatole levels, sexual development and performance parameters in pigs. Frequencies of the T allele were 6.7% for Swedish Yorkshire × Landrace crossbred pigs (n = 245), 6.5% for Swedish Yorkshire (n = 99) and 12.8% for Landrace breed (n = 74). No deviations from Hardy-Weinberg equilibrium were observed in the investigated populations. In Swedish Yorkshire × Landrace crossbred entire male pigs (n = 193), plasma samples were analysed for skatole, Androstenone, testosterone and oestrone sulphate, and fat samples were analysed for Androstenone, skatole and free oestrone. Additionally, testis weight and bulbourethral gland length for crossbred pigs were recorded. Plasma Androstenone levels were significantly lower in the G/T genotype at 90 kg live weight compared with the wild G/G genotype at the same live weight (P = 0.006). In heavier pigs, plasma Androstenone levels did not differ between genotypes (P = 0.382). Fat Androstenone levels were not affected by CYB5A genotype (P = 0.252). Skatole levels in the G/T genotype at 115 kg live weight were lower compared with those in the G/G genotype in plasma (P = 0.048) and fat (P = 0.028), although no differences were observed in lighter pigs. Testis weight, bulbourethral gland length, testosterone and oestrone sulphate levels in plasma, and oestrone levels in fat were not affected by genotype. We concluded that the presence of the T allele in the CYB5A gene resulted in lower Androstenone levels in plasma, and lower skatole levels in fat and plasma; this reduction, however, was dependent on the live weight of the animals. Reproductive hormones and growth rate did not differ between the pigs of different genotypes, whereas a higher lean meat content was found in the G/T genotype in comparison with the G/G genotype. The practical application of those results in Sweden is doubtful because of lack of the effect on Androstenone in fat and the low frequency of the T allele in the studied Swedish pig populations.
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gene expression of 3β hydroxysteroid dehydrogenase and 17β hydroxysteroid dehydrogenase in relation to Androstenone testosterone and estrone sulphate in gonadally intact male and castrated pigs
Journal of Animal Science, 2007Co-Authors: G Chen, Galia Zamaratskaia, E Bourneuf, S Marklund, A Madej, K LundstromAbstract:Androstenone is one of the main compounds responsible for boar taint, and 3beta-hydroxysteroid dehydrogenase (3betaHSD) might be involved in its metabolism. In this study, the gene expression of 3betaHSD and 17beta-hydroxysteroid dehydrogenase (17betaHSD) were determined by real-time PCR analysis and related to the concentrations of Androstenone, testosterone, and estrone sulphate (E1S). The experiments were performed on gonadally intact male pigs classified based on high or low fat Androstenone concentrations, as predetermined by HPLC, as well as on immunocastrated and surgically castrated male pigs. The male pigs with high Androstenone concentrations in fat had low 3betaHSD gene expression in liver and testis. Moreover, the 17betaHSD gene expression in liver, but not in testis, varied negatively with fat Androstenone concentrations. Immunocastrated and surgically castrated male pigs had nondetectable concentrations of fat Androstenone and plasma testosterone and E1S, and the castration procedure induced a significant increase of 3betaHSD and 17betaHSD gene expression. The mRNA expression was generally much greater from the 3betaHSD than from the 17betaHSD gene. Furthermore, fat Androstenone was negatively correlated with liver 3betaHSD gene expression (Pearson correlation, r = -0.69; P < 0.05), and the 17betaHSD gene expression in liver was negatively correlated with plasma E1S (r = -0.95; P < 0.001), indicating an important role of liver 17betaHSD in the estrogen metabolism of gonadally intact male pigs. Another strong correlation was found between 3betaHSD and 17betaHSD gene expression in liver of the gonadally intact male pigs (r = 0.86; P < 0.01), possibly reflecting similar regulation mechanisms of these genes.
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effects of raw potato starch and live weight on fat and plasma skatole indole and Androstenone levels measured by different methods in entire male pigs
Food Chemistry, 2007Co-Authors: G Chen, Galia Zamaratskaia, H K Andersson, K LundstromAbstract:Abstract A total of 96 entire male pigs were used to evaluate the effects of feeding raw potato starch (RPS) and live weight (LW; 90, 100 or 115 kg) on skatole, indole and Androstenone levels in fat and plasma. Different methods to analyse the compounds were compared. Fat levels of skatole analysed by HPLC and colorimetric methods, and Androstenone analysed by HPLC and ELISA, were highly correlated. However, Androstenone values obtained by ELISA were overestimated. Feeding RPS reduced skatole levels in plasma and fat but did not affect indole levels. Androstenone levels in plasma measured by direct ELISA were not altered by diet, whereas the levels measured by ELISA with extraction were lower in the pigs fed RPS. Feeding RPS did not reduce Androstenone levels in fat. Androstenone levels in fat were higher at 115 than at 90 kg, whereas skatole and indole levels were not affected by LW.