The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
José Luis Vázquez Noguera - One of the best experts on this subject based on the ideXlab platform.
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fine mapping of porcine chromosome 6 qtl and lepr effects on body composition in multiple generations of an iberian by Landrace intercross
Genetics Research, 2005Co-Authors: Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, C Barragan, C Rodriguez, A Fernandez, R Leton, A Mercade, E Alves, Luis VaronaAbstract:The leptin receptor gene ( LEPR ) is a candidate for traits related to growth and body composition, and is located on SSC6 in a region where fatness and meat composition quantitative trait loci (QTL) have previously been detected in several F 2 experimental designs. The aims of this work were: (i) to fine map these QTL on a larger sample of animals and generations (F 3 and backcross) of an Iberian×Landrace intercross and (ii) to examine the effects of LEPR alleles on body composition traits. Eleven single nucleotide polymorphisms (SNPs) were detected by sequencing LEPR coding regions in Iberian and Landrace Pig samples. Three missense polymorphisms were genotyped by pyrosequencing in 33 F 0 , 70 F 1 , 418 F 2 , 86 F 3 and 128 individuals coming from the backcross of four F 2 males with 24 Landrace females. Thirteen microsatellites and one SNP were also genotyped. Traits analysed were: backfat thickness at different locations (BF T ), intramuscular fat percentage (IMF P ), eye muscle area (EM A ), loin depth (LO D ), weight of shoulder (SH W ), weight of ribs (RIB W ) and weight of belly bacon (BB W ). Different statistical models were applied in order to evaluate the number and effects of QTL on chromosome 6 and the possible causality of the LEPR gene variants with respect to the QTL. The results support the presence of two QTL on SSC6. One, at position 60–100 cM, affects BF T and RIB W . The other and more significant maps in a narrow region (130–132 cM) and affects BF T , IMF P , EM A , LO D , SH W , RIB W and BB W . Results also support the association between LEPR alleles and BF T traits. The possible functional implications of the analysed polymorphisms are considered.
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identification of carcass and meat quality quantitative trait loci in a Landrace Pig population selected for growth and leanness
Journal of Animal Science, 2005Co-Authors: O Vidal, José Luis Vázquez Noguera, Luis Varona, M Amills, N Jimenez, G Davalos, J M Folch, A SanchezAbstract:: The identification of QTL related to production traits that are relevant for the Pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on Pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.
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derivation of a bayes factor to distinguish between linked or pleiotropic quantitative trait loci
Genetics, 2004Co-Authors: Luis Varona, L Gomezraya, Wendy M. Rauw, Alex Clop, Cristina Óvilo, José Luis Vázquez NogueraAbstract:A simple procedure to calculate the Bayes factor between linked and pleiotropic QTL models is presented. The Bayes factor is calculated from the marginal prior and posterior densities of the locations of the QTL under a linkage and a pleiotropy model. The procedure is computed with a Gibbs sampler, and it can be easily applied to any model including the location of the QTL as a variable. The procedure was compared with a multivariate least-squares method. The proposed procedure showed better results in terms of power of detection of linkage when low information is available. As information increases, the performance of both procedures becomes similar. An example using data provided by an Iberian by Landrace Pig intercross is presented. The results showed that three different QTL segregate in SSC6: a pleiotropic QTL affects myristic, palmitic, and eicosadienoic fatty acids; another pleiotropic QTL affects palmitoleic, stearic, and vaccenic fatty acids; and a third QTL affects the percentage of linoleic acid. In the example, the Bayes factor approach was more powerful than the multivariate least-squares approach.
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Estrogen receptor polymorphism in Landrace Pigs and its association with litter size performance
Livestock Production Science, 2003Co-Authors: José Luis Vázquez Noguera, Luis Varona, D Babot, L. Gomez-raya, Armand Sánchez, Joan Estany, L.a. Messer, Max F. Rothschild, Miguel Pérez-encisoAbstract:Polymorphism at the estrogen receptor locus (ESR) and its association with reproductive performance in Landrace Pig is reported. A total of 124 sows from a control line, and 163 sows from a line selected for litter size were genotyped. The traits studied were number born alive (NBA) and total number born (TNB). Prolificacy in first, second and third or later parities were considered as three different traits. A mixed model considering the ESR genotype as a fixed effect and polygenic background as a random effect, was carried out using Bayesian inference, implemented via the Gibbs sampling procedure. Two alternative statistical models, with and without ESR genotype by line interaction, were considered. Association of an additive ESR effect with NBA and TNB was not detected. Moreover, in third and further parities, a line by ESR genotype interaction was observed for both NBA and TNB. For third and further parities, allele B was associated with increasing litter size in selected animals, whereas the opposite was observed in control animals. These results suggest that a background genotype by ESR interaction exists, although a spurious association due to sampling or the possibility of different linkage phases between the ESR polymorphism and a putative QTL close by cannot be ruled out.
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quantitative trait locus mapping for meat quality traits in an iberian Landrace f2 Pig population1
Journal of Animal Science, 2002Co-Authors: Cristina Óvilo, Alex Clop, José Luis Vázquez Noguera, Agustina Coll, C Barragan, M A Toro, M A Oliver, C Rodriguez, L Silio, J M FolchAbstract:An experimental F 2 cross between Iberian and Landrace Pig strains was performed to map quantitative trait loci (QTL) for diverse productive traits. Here we report results for meat quality traits from 369 F 2 animals with records for pH 24 h postmortem (pH 24 h), muscle color Minolta measurements L* (lightness), a* (redness), and b* (yellowness), H* (hue angle), C* (chroma), intramuscular fat (IMF) and haematin Pigment content measured in the longissimus thoracis. Pigs were genotyped for 92 markers covering the 18 porcine autosomes (SSC). Results of the genome scan show evidence for QTL for IMF (SSC6; F = 27.16), pH 24 h (SSC3; F = 7.73), haematin Pigments (SSC4 and SSC7; F = 8.68 and 9.47 respectively) and Minolta color measurements L* (SSC4 and SSC7; F = 16.42 and 7.17 respectively), and a* (SSC4 and SSC8; F = 8.05 and 7.36 respectively). No QTL were observed for the color measurements b*, H*, and C*. Alternative models fitting epistasis between QTL were also tested, but detected epistatic interactions were not significant at a genome-wise level. In this work we identify genomic regions related with meat quality traits. Improvement by traditional selection methods is complicated, and finer mapping would be required for their application in introgression programs.
Luis Varona - One of the best experts on this subject based on the ideXlab platform.
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identification of carcass and meat quality quantitative trait loci in a Landrace Pig population selected for growth and leanness
Journal of Animal Science, 2005Co-Authors: O Vidal, José Luis Vázquez Noguera, Luis Varona, M Amills, N Jimenez, G Davalos, J M Folch, A SanchezAbstract:: The identification of QTL related to production traits that are relevant for the Pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on Pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.
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fine mapping of porcine chromosome 6 qtl and lepr effects on body composition in multiple generations of an iberian by Landrace intercross
Genetics Research, 2005Co-Authors: Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, C Barragan, C Rodriguez, A Fernandez, R Leton, A Mercade, E Alves, Luis VaronaAbstract:The leptin receptor gene ( LEPR ) is a candidate for traits related to growth and body composition, and is located on SSC6 in a region where fatness and meat composition quantitative trait loci (QTL) have previously been detected in several F 2 experimental designs. The aims of this work were: (i) to fine map these QTL on a larger sample of animals and generations (F 3 and backcross) of an Iberian×Landrace intercross and (ii) to examine the effects of LEPR alleles on body composition traits. Eleven single nucleotide polymorphisms (SNPs) were detected by sequencing LEPR coding regions in Iberian and Landrace Pig samples. Three missense polymorphisms were genotyped by pyrosequencing in 33 F 0 , 70 F 1 , 418 F 2 , 86 F 3 and 128 individuals coming from the backcross of four F 2 males with 24 Landrace females. Thirteen microsatellites and one SNP were also genotyped. Traits analysed were: backfat thickness at different locations (BF T ), intramuscular fat percentage (IMF P ), eye muscle area (EM A ), loin depth (LO D ), weight of shoulder (SH W ), weight of ribs (RIB W ) and weight of belly bacon (BB W ). Different statistical models were applied in order to evaluate the number and effects of QTL on chromosome 6 and the possible causality of the LEPR gene variants with respect to the QTL. The results support the presence of two QTL on SSC6. One, at position 60–100 cM, affects BF T and RIB W . The other and more significant maps in a narrow region (130–132 cM) and affects BF T , IMF P , EM A , LO D , SH W , RIB W and BB W . Results also support the association between LEPR alleles and BF T traits. The possible functional implications of the analysed polymorphisms are considered.
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derivation of a bayes factor to distinguish between linked or pleiotropic quantitative trait loci
Genetics, 2004Co-Authors: Luis Varona, L Gomezraya, Wendy M. Rauw, Alex Clop, Cristina Óvilo, José Luis Vázquez NogueraAbstract:A simple procedure to calculate the Bayes factor between linked and pleiotropic QTL models is presented. The Bayes factor is calculated from the marginal prior and posterior densities of the locations of the QTL under a linkage and a pleiotropy model. The procedure is computed with a Gibbs sampler, and it can be easily applied to any model including the location of the QTL as a variable. The procedure was compared with a multivariate least-squares method. The proposed procedure showed better results in terms of power of detection of linkage when low information is available. As information increases, the performance of both procedures becomes similar. An example using data provided by an Iberian by Landrace Pig intercross is presented. The results showed that three different QTL segregate in SSC6: a pleiotropic QTL affects myristic, palmitic, and eicosadienoic fatty acids; another pleiotropic QTL affects palmitoleic, stearic, and vaccenic fatty acids; and a third QTL affects the percentage of linoleic acid. In the example, the Bayes factor approach was more powerful than the multivariate least-squares approach.
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Estrogen receptor polymorphism in Landrace Pigs and its association with litter size performance
Livestock Production Science, 2003Co-Authors: José Luis Vázquez Noguera, Luis Varona, D Babot, L. Gomez-raya, Armand Sánchez, Joan Estany, L.a. Messer, Max F. Rothschild, Miguel Pérez-encisoAbstract:Polymorphism at the estrogen receptor locus (ESR) and its association with reproductive performance in Landrace Pig is reported. A total of 124 sows from a control line, and 163 sows from a line selected for litter size were genotyped. The traits studied were number born alive (NBA) and total number born (TNB). Prolificacy in first, second and third or later parities were considered as three different traits. A mixed model considering the ESR genotype as a fixed effect and polygenic background as a random effect, was carried out using Bayesian inference, implemented via the Gibbs sampling procedure. Two alternative statistical models, with and without ESR genotype by line interaction, were considered. Association of an additive ESR effect with NBA and TNB was not detected. Moreover, in third and further parities, a line by ESR genotype interaction was observed for both NBA and TNB. For third and further parities, allele B was associated with increasing litter size in selected animals, whereas the opposite was observed in control animals. These results suggest that a background genotype by ESR interaction exists, although a spurious association due to sampling or the possibility of different linkage phases between the ESR polymorphism and a putative QTL close by cannot be ruled out.
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qtl mapping for growth and carcass traits in an iberian by Landrace Pig intercross additive dominant and epistatic effects
Genetics Research, 2002Co-Authors: Luis Varona, Alex Clop, Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, Miguel Perezenciso, Agustina Coll, C Barragan, M A Toro, D BabotAbstract:: Results from a QTL experiment on growth and carcass traits in an experimental F2 cross between Iberian and Landrace Pigs are reported. Phenotypic data for growth, length of carcass and muscle mass, fat deposition and carcass composition traits from 321 individuals corresponding to 58 families were recorded. Animals were genotyped for 92 markers covering the 18 porcine autosomes (SSC). The results from the genomic scan show genomewide significant QTL in SSC2 (longissimus muscle area and backfat thickness), SSC4 (length of carcass, backfat thickness, loin, shoulder and belly bacon weights) and SSC6 (longissimus muscle area, backfat thickness, loin, shoulder and belly bacon weights). Suggestive QTL were also found on SSC1, SSC5, SSC7, SSC8, SSC9, SSC13, SCC14, SSC16 and SSC17. A bidimensional genomic scan every 10 cM was performed to detect interaction between QTL. The joint action of two suggestive QTL in SSC2 and SSC17 led to a genome-wide significant effect in live weight. The results of the bidimensional genomic scan showed that the genetic architecture was mainly additive or the experimental set-up did not have enough power to detect epistatic interactions.
J M Folch - One of the best experts on this subject based on the ideXlab platform.
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identification of carcass and meat quality quantitative trait loci in a Landrace Pig population selected for growth and leanness
Journal of Animal Science, 2005Co-Authors: O Vidal, José Luis Vázquez Noguera, Luis Varona, M Amills, N Jimenez, G Davalos, J M Folch, A SanchezAbstract:: The identification of QTL related to production traits that are relevant for the Pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on Pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.
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fine mapping of porcine chromosome 6 qtl and lepr effects on body composition in multiple generations of an iberian by Landrace intercross
Genetics Research, 2005Co-Authors: Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, C Barragan, C Rodriguez, A Fernandez, R Leton, A Mercade, E Alves, Luis VaronaAbstract:The leptin receptor gene ( LEPR ) is a candidate for traits related to growth and body composition, and is located on SSC6 in a region where fatness and meat composition quantitative trait loci (QTL) have previously been detected in several F 2 experimental designs. The aims of this work were: (i) to fine map these QTL on a larger sample of animals and generations (F 3 and backcross) of an Iberian×Landrace intercross and (ii) to examine the effects of LEPR alleles on body composition traits. Eleven single nucleotide polymorphisms (SNPs) were detected by sequencing LEPR coding regions in Iberian and Landrace Pig samples. Three missense polymorphisms were genotyped by pyrosequencing in 33 F 0 , 70 F 1 , 418 F 2 , 86 F 3 and 128 individuals coming from the backcross of four F 2 males with 24 Landrace females. Thirteen microsatellites and one SNP were also genotyped. Traits analysed were: backfat thickness at different locations (BF T ), intramuscular fat percentage (IMF P ), eye muscle area (EM A ), loin depth (LO D ), weight of shoulder (SH W ), weight of ribs (RIB W ) and weight of belly bacon (BB W ). Different statistical models were applied in order to evaluate the number and effects of QTL on chromosome 6 and the possible causality of the LEPR gene variants with respect to the QTL. The results support the presence of two QTL on SSC6. One, at position 60–100 cM, affects BF T and RIB W . The other and more significant maps in a narrow region (130–132 cM) and affects BF T , IMF P , EM A , LO D , SH W , RIB W and BB W . Results also support the association between LEPR alleles and BF T traits. The possible functional implications of the analysed polymorphisms are considered.
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quantitative trait locus mapping for meat quality traits in an iberian Landrace f2 Pig population1
Journal of Animal Science, 2002Co-Authors: Cristina Óvilo, Alex Clop, José Luis Vázquez Noguera, Agustina Coll, C Barragan, M A Toro, M A Oliver, C Rodriguez, L Silio, J M FolchAbstract:An experimental F 2 cross between Iberian and Landrace Pig strains was performed to map quantitative trait loci (QTL) for diverse productive traits. Here we report results for meat quality traits from 369 F 2 animals with records for pH 24 h postmortem (pH 24 h), muscle color Minolta measurements L* (lightness), a* (redness), and b* (yellowness), H* (hue angle), C* (chroma), intramuscular fat (IMF) and haematin Pigment content measured in the longissimus thoracis. Pigs were genotyped for 92 markers covering the 18 porcine autosomes (SSC). Results of the genome scan show evidence for QTL for IMF (SSC6; F = 27.16), pH 24 h (SSC3; F = 7.73), haematin Pigments (SSC4 and SSC7; F = 8.68 and 9.47 respectively) and Minolta color measurements L* (SSC4 and SSC7; F = 16.42 and 7.17 respectively), and a* (SSC4 and SSC8; F = 8.05 and 7.36 respectively). No QTL were observed for the color measurements b*, H*, and C*. Alternative models fitting epistasis between QTL were also tested, but detected epistatic interactions were not significant at a genome-wise level. In this work we identify genomic regions related with meat quality traits. Improvement by traditional selection methods is complicated, and finer mapping would be required for their application in introgression programs.
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qtl mapping for growth and carcass traits in an iberian by Landrace Pig intercross additive dominant and epistatic effects
Genetics Research, 2002Co-Authors: Luis Varona, Alex Clop, Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, Miguel Perezenciso, Agustina Coll, C Barragan, M A Toro, D BabotAbstract:: Results from a QTL experiment on growth and carcass traits in an experimental F2 cross between Iberian and Landrace Pigs are reported. Phenotypic data for growth, length of carcass and muscle mass, fat deposition and carcass composition traits from 321 individuals corresponding to 58 families were recorded. Animals were genotyped for 92 markers covering the 18 porcine autosomes (SSC). The results from the genomic scan show genomewide significant QTL in SSC2 (longissimus muscle area and backfat thickness), SSC4 (length of carcass, backfat thickness, loin, shoulder and belly bacon weights) and SSC6 (longissimus muscle area, backfat thickness, loin, shoulder and belly bacon weights). Suggestive QTL were also found on SSC1, SSC5, SSC7, SSC8, SSC9, SSC13, SCC14, SSC16 and SSC17. A bidimensional genomic scan every 10 cM was performed to detect interaction between QTL. The joint action of two suggestive QTL in SSC2 and SSC17 led to a genome-wide significant effect in live weight. The results of the bidimensional genomic scan showed that the genetic architecture was mainly additive or the experimental set-up did not have enough power to detect epistatic interactions.
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exploring alternative models for sex linked quantitative trait loci in outbred populations application to an iberian x Landrace Pig intercross
Genetics, 2002Co-Authors: Miguel Perezenciso, Alex Clop, Cristina Óvilo, Luis Varona, J M Folch, A Sanchez, C Barragan, Maria Angels Oliver, José Luis Vázquez NogueraAbstract:We present a very flexible method that allows us to analyze X-linked quantitative trait loci (QTL) in crosses between outbred lines. The dosage compensation phenomenon is modeled explicitly in an identity-by-descent approach. A variety of models can be fitted, ranging from considering alternative fixed alleles within the founder breeds to a model where the only genetic variation is within breeds, as well as mixed models. Different genetic variances within each founder breed can be estimated. We illustrate the method with data from an F(2) cross between Iberian x Landrace Pigs for intramuscular fat content and meat color component a*. The Iberian allele exhibited a strong overdominant effect for intramuscular fat in females. There was also limited evidence of one or more regions affecting color component a*. The analysis suggested that the QTL alleles were fixed in the Iberian founders, whereas there was some evidence of segregation in Landrace for the QTL affecting a* color component.
Cristina Óvilo - One of the best experts on this subject based on the ideXlab platform.
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fine mapping of porcine chromosome 6 qtl and lepr effects on body composition in multiple generations of an iberian by Landrace intercross
Genetics Research, 2005Co-Authors: Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, C Barragan, C Rodriguez, A Fernandez, R Leton, A Mercade, E Alves, Luis VaronaAbstract:The leptin receptor gene ( LEPR ) is a candidate for traits related to growth and body composition, and is located on SSC6 in a region where fatness and meat composition quantitative trait loci (QTL) have previously been detected in several F 2 experimental designs. The aims of this work were: (i) to fine map these QTL on a larger sample of animals and generations (F 3 and backcross) of an Iberian×Landrace intercross and (ii) to examine the effects of LEPR alleles on body composition traits. Eleven single nucleotide polymorphisms (SNPs) were detected by sequencing LEPR coding regions in Iberian and Landrace Pig samples. Three missense polymorphisms were genotyped by pyrosequencing in 33 F 0 , 70 F 1 , 418 F 2 , 86 F 3 and 128 individuals coming from the backcross of four F 2 males with 24 Landrace females. Thirteen microsatellites and one SNP were also genotyped. Traits analysed were: backfat thickness at different locations (BF T ), intramuscular fat percentage (IMF P ), eye muscle area (EM A ), loin depth (LO D ), weight of shoulder (SH W ), weight of ribs (RIB W ) and weight of belly bacon (BB W ). Different statistical models were applied in order to evaluate the number and effects of QTL on chromosome 6 and the possible causality of the LEPR gene variants with respect to the QTL. The results support the presence of two QTL on SSC6. One, at position 60–100 cM, affects BF T and RIB W . The other and more significant maps in a narrow region (130–132 cM) and affects BF T , IMF P , EM A , LO D , SH W , RIB W and BB W . Results also support the association between LEPR alleles and BF T traits. The possible functional implications of the analysed polymorphisms are considered.
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derivation of a bayes factor to distinguish between linked or pleiotropic quantitative trait loci
Genetics, 2004Co-Authors: Luis Varona, L Gomezraya, Wendy M. Rauw, Alex Clop, Cristina Óvilo, José Luis Vázquez NogueraAbstract:A simple procedure to calculate the Bayes factor between linked and pleiotropic QTL models is presented. The Bayes factor is calculated from the marginal prior and posterior densities of the locations of the QTL under a linkage and a pleiotropy model. The procedure is computed with a Gibbs sampler, and it can be easily applied to any model including the location of the QTL as a variable. The procedure was compared with a multivariate least-squares method. The proposed procedure showed better results in terms of power of detection of linkage when low information is available. As information increases, the performance of both procedures becomes similar. An example using data provided by an Iberian by Landrace Pig intercross is presented. The results showed that three different QTL segregate in SSC6: a pleiotropic QTL affects myristic, palmitic, and eicosadienoic fatty acids; another pleiotropic QTL affects palmitoleic, stearic, and vaccenic fatty acids; and a third QTL affects the percentage of linoleic acid. In the example, the Bayes factor approach was more powerful than the multivariate least-squares approach.
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quantitative trait locus mapping for meat quality traits in an iberian Landrace f2 Pig population1
Journal of Animal Science, 2002Co-Authors: Cristina Óvilo, Alex Clop, José Luis Vázquez Noguera, Agustina Coll, C Barragan, M A Toro, M A Oliver, C Rodriguez, L Silio, J M FolchAbstract:An experimental F 2 cross between Iberian and Landrace Pig strains was performed to map quantitative trait loci (QTL) for diverse productive traits. Here we report results for meat quality traits from 369 F 2 animals with records for pH 24 h postmortem (pH 24 h), muscle color Minolta measurements L* (lightness), a* (redness), and b* (yellowness), H* (hue angle), C* (chroma), intramuscular fat (IMF) and haematin Pigment content measured in the longissimus thoracis. Pigs were genotyped for 92 markers covering the 18 porcine autosomes (SSC). Results of the genome scan show evidence for QTL for IMF (SSC6; F = 27.16), pH 24 h (SSC3; F = 7.73), haematin Pigments (SSC4 and SSC7; F = 8.68 and 9.47 respectively) and Minolta color measurements L* (SSC4 and SSC7; F = 16.42 and 7.17 respectively), and a* (SSC4 and SSC8; F = 8.05 and 7.36 respectively). No QTL were observed for the color measurements b*, H*, and C*. Alternative models fitting epistasis between QTL were also tested, but detected epistatic interactions were not significant at a genome-wise level. In this work we identify genomic regions related with meat quality traits. Improvement by traditional selection methods is complicated, and finer mapping would be required for their application in introgression programs.
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qtl mapping for growth and carcass traits in an iberian by Landrace Pig intercross additive dominant and epistatic effects
Genetics Research, 2002Co-Authors: Luis Varona, Alex Clop, Cristina Óvilo, José Luis Vázquez Noguera, J M Folch, Miguel Perezenciso, Agustina Coll, C Barragan, M A Toro, D BabotAbstract:: Results from a QTL experiment on growth and carcass traits in an experimental F2 cross between Iberian and Landrace Pigs are reported. Phenotypic data for growth, length of carcass and muscle mass, fat deposition and carcass composition traits from 321 individuals corresponding to 58 families were recorded. Animals were genotyped for 92 markers covering the 18 porcine autosomes (SSC). The results from the genomic scan show genomewide significant QTL in SSC2 (longissimus muscle area and backfat thickness), SSC4 (length of carcass, backfat thickness, loin, shoulder and belly bacon weights) and SSC6 (longissimus muscle area, backfat thickness, loin, shoulder and belly bacon weights). Suggestive QTL were also found on SSC1, SSC5, SSC7, SSC8, SSC9, SSC13, SCC14, SSC16 and SSC17. A bidimensional genomic scan every 10 cM was performed to detect interaction between QTL. The joint action of two suggestive QTL in SSC2 and SSC17 led to a genome-wide significant effect in live weight. The results of the bidimensional genomic scan showed that the genetic architecture was mainly additive or the experimental set-up did not have enough power to detect epistatic interactions.
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exploring alternative models for sex linked quantitative trait loci in outbred populations application to an iberian x Landrace Pig intercross
Genetics, 2002Co-Authors: Miguel Perezenciso, Alex Clop, Cristina Óvilo, Luis Varona, J M Folch, A Sanchez, C Barragan, Maria Angels Oliver, José Luis Vázquez NogueraAbstract:We present a very flexible method that allows us to analyze X-linked quantitative trait loci (QTL) in crosses between outbred lines. The dosage compensation phenomenon is modeled explicitly in an identity-by-descent approach. A variety of models can be fitted, ranging from considering alternative fixed alleles within the founder breeds to a model where the only genetic variation is within breeds, as well as mixed models. Different genetic variances within each founder breed can be estimated. We illustrate the method with data from an F(2) cross between Iberian x Landrace Pigs for intramuscular fat content and meat color component a*. The Iberian allele exhibited a strong overdominant effect for intramuscular fat in females. There was also limited evidence of one or more regions affecting color component a*. The analysis suggested that the QTL alleles were fixed in the Iberian founders, whereas there was some evidence of segregation in Landrace for the QTL affecting a* color component.
Murali Gopalakrishnan - One of the best experts on this subject based on the ideXlab platform.
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Functional characterization of large conductance calcium-activated K^+ channel openers in bladder and vascular smooth muscle
Naunyn-Schmiedeberg's Archives of Pharmacology, 2004Co-Authors: John Malysz, Steven A Buckner, Ivan Milicic, Anthony V. Daza, Arturo Perez-medrano, Murali GopalakrishnanAbstract:Calcium activated K^+ channels (K_Ca channels) are found in a variety of smooth muscle tissues, the most characterized of which are the large conductance K_Ca channels (BK_Ca or maxi-K^+ channels). Recent medicinal chemistry efforts have identified novel BK_Ca openers including 2-amino-5-(2-fluoro-phenyl)-4-methyl-1H-pyrrole-3-carbonitrile (NS-8), BMS-204352 and its analog 3-(5-chloro-2-hydroxy-phenyl)-3-hydroxy-6-trifluoromethyl-1,3-dihydro-indol-2-one (compound 1), and 5,7-dichloro-4-(5-chloro-2-hydroxy-phenyl)-3-hydroxy-1H-quinolin-2-one (compound 2). Although these compounds are effective BK_Ca openers as shown by electrophysiological methods, little is known about their effects on smooth muscle contractility. In this study, the responsiveness of structurally diverse BK_Ca openers—NS-8, compounds 1 and 2 and the well characterized nonselective NS-1619—was assessed using segments of endothelium denuded rat aorta, rat and guinea Pig detrusor precontracted with extracellular K^+, and Landrace Pig detrusor stimulated by electrical field. In all preparations, the compounds tested inhibited or completely abolished contractions with similar potencies (−logIC_50 values: 3.8 to 5.1). In rat aorta, in the presence of 80 mM K^+, the compounds significantly shifted the concentration-response curve to the right compared with those obtained in 30 mM K^+. These data are consistent with K^+ channel (BK_Ca channel) activation as the underlying mechanism of relaxation by compounds that share the electrophysiological property of BK_Ca current activation. The similar potencies at detrusor and vascular smooth muscle suggest that the achievement of smooth muscle selectivity in vitro with the representative compounds examined in this study may prove to be a challenge when targeting BK_Ca channels for smooth muscle indications such as overactive bladder.
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the discovery of a new class of large conductance ca2 activated k channel opener targeted for overactive bladder synthesis and structure activity relationships of 2 amino 4 azaindoles
Bioorganic & Medicinal Chemistry Letters, 2003Co-Authors: Sean C Turner, William A Carroll, Tammie K White, Murali Gopalakrishnan, Michael J Coghlan, Charchang Shieh, Xufeng Zhang, Ashutosh S Parihar, Steven A Buckner, Ivan MilicicAbstract:Abstract 2-Amino-4-azaindoles have been identified as a structurally novel class of BK Ca channel openers. Their synthesis from 2-chloro-3-nitropyridine is described together with their in vitro properties assessed by 86 Rb + efflux and whole-cell patch-clamp assays using HEK293 cells stably transfected with the BK Ca α subunit. In vitro functional characterization of BK Ca channel opening activity was also assessed by measurement of relaxation of smooth muscle tissue strips obtained from Landrace Pig bladders. The preliminary SAR data indicate the importance of steric bulk around the 2-amino substituent.
