HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Estellé, J. Articles by Folch, J. M. Search for Related Content PubMed PubMed Citation Articles by Estellé, J. Articles by Folch, J. M.

Effect of the porcine IGF2-intron3-G3072A substitution in an outbred Large White population and in an Iberian x Landrace cross¹

J. Estellé^*,2, A. Mercadé^*, J. L. Noguera, M. Pérez-Enciso^*,, C. Óvilo, A. Sánchez^* and J. M. Folch^*

^* Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain; and Àrea de Producció Animal, Centre UdL-IRTA, C/Alcalde Rovira Roure 177, 25198, Lleida, Spain; and Institut Català de Recerca i Estudis Avançats, C/Lluis Companys 23, 08010, Barcelona, Spain; and and Dpto. Mejora Genética Animal SGIT-INIA, Ctra. De la Coruña Km. 7, 28040, Madrid, Spain

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

 
The IGF2-intron3-G3072A substitution has been recently described as the causal factor of the imprinted QTL for fat deposition and muscle growth detected within the porcine IGF2 region. The objective of this study was to investigate the IGF2 substitution effect in a Large White outbred population and in an Iberian x Landrace F₂ cross. The results showed that the substitution has significant effects on fatness, growth, and shape traits with estimated effects in the expected direction. These results agree with those obtained in the F₂ cross, where the IGF2-intron3-G3072A substitution is segregating only in a small family. In addition, a QTL scan has been performed in the F₂ population for the traits used in the IGF2 substitution effect validation. Results of this study demonstrated that there are QTL segregating in swine chromosome 2 other than the IGF2 substitution for carcass weight, LM area, and pH measured at 24 h after slaughter. The results confirm the relevance of the IGF2 substitution, but they also show that there are still valuable mutations to be revealed in this chromosome.

Key Words: Fatness • Growth • IGF2 • Pig • Quantitative Trait Loci

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

 
Since the early 1990s, several QTL mapping experiments have been developed in the pig; many of them have used intercrosses between divergent breeds (Bidanel and Rothschild, 2002; Hu et al., 2005). In particular, some QTL initially detected in experimental crosses have also been found to be segregating within commercial pig populations (Evans et al., 2003; de Koning et al., 2003; Nagamine et al., 2003) and have confirmed the utility that these approaches can have for the pig breeding industry.

The causal mutations of the majority of QTL in domestic animals are thus far unknown (Andersson and Georges, 2004). One of the exceptions is the QTL localized in the SSC 2 IGF2 region. A paternally expressed QTL affecting muscle growth, fat deposition, and heart size was localized in the IGF2 region (Jeon et al., 1999; Nezer et al., 1999) and was confirmed by de Koning et al. (2000) and Thomsen et al. (2004). Recently, Van Laere et al. (2003) reported that the IGF2-intron3-G3072A substitution, localized in a highly conserved regulatory region that binds a repressor nuclear factor, is the causal mutation of that QTL. Jungerius et al. (2004) reported that the IGF2 substitution explains a backfat thickness QTL.

Evans et al. (2003) and de Koning et al. (2003) analyzed the Large White commercial population for the presence of QTL, but inconsistent results for fatness traits were obtained in the IGF2 region. Previous results in the Iberian x Landrace intercross reported a QTL in SSC 2, but not within the IGF2 region (Varona et al., 2002).

The objectives of the present work were to test the IGF2 substitution effect in the Large White commercial population and in the Iberian x Landrace F₂ intercross and to determine whether additional QTL are segregating on SSC 2 in the F₂ population.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

 
Animal Material and Traits Analyzed

Both the Large White and F₂ cross, together with the phenotypes recorded, have been described extensively elsewhere (Varona et al., 2002; de Koning et al., 2003; Evans et al., 2003). In brief, the Large White population (COPAGA Cooperative, Lleida, Spain) consisted of five sires, 54 females, and 387 offspring; the F₂ cross pedigree was derived from 34 parents (three Iberian boars and 31 Landrace sows), 79 F₁, and 321 F₂ animals (NOVA GENÈTICA, S. A., Lleida, Spain). Animals were maintained under intensive conditions, and feeding was ad libitum with a cereal-based commercial diet (13.4 MJ of ME /kg, 17.5% CP, 1% lysine; as-fed basis). The objectives of the two experiments were quite different: in the Large White population, the purpose was to confirm, in a commercial population, the segregation of QTL previously described in experimental crosses, whereas the F₂ cross was designed to perform a genome scan for the detection of QTL for growth, fatness, and meat quality traits.

The traits recorded in the Large White and F₂ populations were subcutaneous backfat thickness at 6 cm off the midline between the third and fourth ribs using the SFK Fat-o-Meater (SFK Technology A/S, Herlev, Denmark) probe (G2), backfat thickness measured with a ruler at the last rib (BF2), carcass weight (CW), LM area (LMA), ham weight (HW), shoulder weight (SW), and pH at 24 h postmortem in the semimembranosus muscle (pH24h). Measurements of LM were available only in the Iberian x Landrace F₂ intercross.

Genotyping

The genotyping of the IGF2 substitution was done as described by Van Laere et al. (2003) in a PSQ HS 96 system (Pyrosequencing AB, Uppsala, Sweden). Once the sires’ genotypes were obtained, the offspring from heterozygous boars and homozygous sows were genotyped so that the allele transmitted could be determined unambiguously. The offspring of AA and GG sires were assigned the A or G haplotypes, respectively. Ten micro-satellites and the IGF2 substitution (marker IGF2) were used in the F₂ population. The positions (in cM) of the markers obtained with CRIMAP 2.4 (Green et al., 1990) were IGF2 (0.0) – SWC9 (0.1) – S0141 (30.1) –SW240 (42.2) – SW1201 (49.2) – SW395 (68.1) – S0226 (75.3) – SW1517 (78.1) – SW1695 (83.7) – S0378 (96.3) –SWR308 (139.1). Three additional microsatellites (SW1201, SW1517, and SW1695) used by Varona et al. (2002) were genotyped. Microsatellite PCR reactions were carried out in an automatic PCR ABI PRISM 877 integrated thermal cycler (Perkin Elmer, Foster City, CA) and analyzed with fluorescent detection in an ABI PRISM 3100 Genetic Analyzer (Applied Biosystems, Foster City, CA). The genotypes were determined using the GeneScan 3.7 analysis software (Applied Biosystems) and stored in the Gemma database (Iannuccelli et al., 1996).

Statistical Analyses

The general model used to test the IGF2 substitution effect in both populations and to perform a QTL scan on SSC 2 in the F₂ cross was

[1]

where y_i is the individual phenotype i; batch_i is the date of slaughter; ß is the covariate coefficient of c_i (CW, except for CW itself, which was corrected by age at slaughter); Pa_i is the probability of the individual being homozygous for alleles of Iberian origin minus the probability of being homozygous for alleles of Landrace origin at the position of interest; Pd_i is the probability of being heterozygous; a_QTL and d_QTL are the QTL additive and dominant effects, respectively; _i is an indicator variable with values – and , depending on whether allele G or A has been received from the sire at the IGF2 substitution; a_IGF2 is the IGF2 substitution effect; u_i is the infinitesimal genetic effect (treated as random with covariance matrix A²_u; A is the numerator relationship matrix); and e_i is the residual.

The SSC 2 region genotyped in the Large White population was restricted to the IGF2 region, whereas a chromosome-wide scan was carried out in the F₂ population. Thus, for the Large White population, the QTL effects a_QTL and d_QTL were not fitted, and only the effect of the IGF2 substitution was tested using a likelihood ratio test. This reduced model was also applied to the F₂ data for the sake of symmetry. In contrast, the full model [1] was fitted every cM along SSC 2 in the F₂ data. Three tests were performed; the IGF2, the QTL, or both QTL and IGF2 effects were tested by removing the appropriate effect(s) from the model. The dominant QTL effect (d_QTL) was excluded from the model when it was not significant (P > 0.05).

In all cases, nominal P values were obtained using the ² approximation to the distribution of the log-likelihood ratios. Maximum likelihood and parameter estimates were obtained via the Qxpak package (Pérez-Enciso and Misztal, 2004). It should be noted that maximum likelihood estimates of random effects are slightly biased with respect to REML, but they allowed us to test fixed effects such as the IGF2 substitution. The Qxpak first estimates the Pa and Pd coefficients via a MCMC algorithm and, in a second step, uses these values to estimate the rest of the parameters. Regarding significance of P-values, permutation tests cannot be applied to the model used here because the infinitesimal effects estimates are meaningless when phenotypes are permuted between related individuals. We have shown previously (Mercadé et al., 2005) that a 1% chromosome-wise significant P-value corresponds roughly to a nominal P-value of 0.001. Although we cannot claim that this is a completely satisfactory solution, here we considered that nominal P-values < 0.001 were significant for the QTL test.

	Results

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

 
Among the five Large White sires, one had genotype AA, three had genotype AG, and one had GG. This finding suggests that the IGF2 substitution is segregating at intermediate frequencies, making it a favorable situation to test the substitution effect. Overall, there were 280 offspring whose IGF2 substitution paternal allele could be assigned. Regarding the F₂ cross, all Iberian males had the wild G allele, whereas the substitution was segregating in the Landrace line (four females of 31 were AG). Only one F1 male with offspring was found to be heterozygous. Its total number of F₂ descendants was 50, of whom 26 inherited the A male’s allele. The rest of F₂ individuals received a G allele from the paternal progenitor. Thus, the F₂ cross is heavily unbalanced regarding the IGF2 genotype, in contrast to the Large White data.

Table 1 shows the results of testing the IGF2 mutation with model [1] without the QTL effects for the sake of comparison between Large White and F₂ populations. The IGF2 substitution effect was significant (P < 0.05) in the Large White population for all traits analyzed, except pH. In contrast, the IGF2 effect was significant only for G2, LMA, and HW in the F₂. Regarding the allele effects, the A allele decreased G2 and BF2 and increased CW, LMA, HW, and SW.

View larger version (30K): [in this window] [in a new window]   Figure 1. The –log10 P-value profiles of the QTL detected in the F2 population (null hypothesis consisted of no QTL in a model including the IGF2 substitution effect). The horizontal line with a value of 2 shows the 0.01 significance level. Traits are backfat thickness at the last rib (BF2), carcass weight (CW), LM area (LMA), ham weight (HW), shoulder weight (SW), and pH at 24 h postmortem (pH24h).

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

In previous analyses of the F₂ cross, we had identified a significant QTL for LMA and LM depth and suggestive QTL for growth and fatness in SSC 2 (Varona et al., 2002). To characterize the contribution of the IGF2 substitution further, as well as other loci to the phenotypic differences in the intercross population, we performed a series of QTL analyses for the same traits used in the IGF2 substitution effect validation and retested the IGF2 substitution effect with a QTL in the model. The results agree with those obtained without a QTL effect in the model (Table 1), so we can conclude that, in the F₂ population, the IGF2 substitution has significant effects on G2, LMA, and HW (P < 0.01). The lack of significance of the IGF2 substitution effect in the other traits, which were significant in the Large White population, could be due to the small size of the F₂ family where the substitution is segregating. We also report additional QTL segregating in this chromosome in the Iberian x Landrace F₂ cross. Taken together, these two facts show that there exists at least one more locus, in addition to the IGF2 substitution, affecting the analyzed traits. The position of the CW QTL is close to that reported for ADG (Bidanel et al., 2001; Malek et al., 2001b). Bidanel et al. (2001), in a cross between Meishan and Large White breeds, showed that the Meishan alleles in SSC 2 were associated with a higher growth rate; in our analyses, the Iberian alleles increased the CW. Thus, the effect is in the opposite direction of phenotype differences in both Meishan and Iberian breeds (differences between Iberian and Landrace breeds are described in Serra et al., 1998). The QTL for LMA detected in the same population by Varona et al. (2002) has been confirmed, and the genotyping of three additional markers allowed the refinement of its localization, which mapped very close to the newly genotyped SW1517 microsatellite. As expected, given the phenotypic differences between breeds, the Landrace alleles increase LMA. As in the case of the SSC 4 QTL (Mercadé et al., 2005), the Iberian alleles of the HW and SW QTL in SSC 2 decreased HW and SW, which agrees with the phenotypic differences between breeds. The HW and SW are corrected for CW so, as argued by Mercadé et al. (2005), they can be considered measurements of the shape of the animals because they measure how total weight is distributed along the different body regions. Malek et al. (2001a) found QTL for water-holding capacity and color traits near the pH24h QTL described here. Because both traits are correlated with pork ultimate pH (Malek et al., 2001a), it can be hypothesized that both QTL may correspond to the same gene. Su et al. (2004) described a suggestive pH QTL in a cross between Large White and Meishan in a position similar to that described in our study. Evans et al. (2003) and de Koning et al. (2003) also described a QTL for pH in SSC 2, but it was within the IGF2 region. In a previous genome scan for meat quality traits using the same Iberian x Landrace F₂ cross, no QTL for pH was detected within SSC 2, although SSC 3 showed one (Ovilo et al., 2002). In the report of Ovilo et al. (2002), there were fewer markers in SSC 2. In particular, two additional markers have been genotyped in the pH24h QTL region. Thus, the appearance of this new QTL could be due to an increased marker density in its region. The breed allelic effects on pH24h are as expected regarding the differences between the two breeds. Finally, Varona et al. (2002) detected a suggestive QTL for fatness in SSC 2 that corresponds with the QTL profile for BF2 presented in Figure 1. Here, the BF2 QTL still remains only suggestive; so, as in Jungerius et al. (2004), additional fatness QTL segregating in this chromosome can be neither confirmed nor excluded.

In conclusion, we have shown that the IGF2 substitution has a large effect in the Large White population and in the F₂ cross, despite the small size of the F₂ family. Our results confirm the intron-3 G3072A substitution as the causal factor of the QTL detected in the IGF2 region with the estimation of the effects in the expected direction. This study has been performed in populations unrelated to those of the original report (Van Laere et al., 2003) and in the Dutch report (Jungerius et al., 2004), conferring additional validity to the relevance of this mutation. An intriguing question is why such a large effect mutation is segregating at intermediate frequencies in highly selected lines such as Landrace or Large White, even more when the causative mutation was evident at high allele frequency in breeds strongly selected for lean growth (Van Laere et al., 2003), and both the IGF2 substitution and the SWC9 microsatellite (within the IGF2 gene) are in Hardy-Weinberg equilibrium in the Large White parental population (data not shown). A possibility is that it has pleiotropic unwanted effects in other traits or that there are counterbalanced QTL with opposite effects in the same chromosome, diminishing the effective selection pressure. The results concerning BF2 in the F₂ cross support this tentative hypothesis (Table 2). Another possibility is that the introduction of the A allele had been recent, and thus a selective sweep is being produced at the current time. This is the hypothesis suggested by Van Laere et al. (2003). In other breeds, such as Pietrain, we have observed that the mutant A allele was fixed, which is in agreement with the IGF2 region results of the Spanish Pietrain population in Evans et al. (2003) and de Koning et al. (2003), perhaps as a result of higher selective pressure for conformation traits and smaller effective sizes than either Large White or Landrace. Thus, the situation may be different from breed to breed. Finally, in addition to confirming the effect of the IGF2 substitution, we also have found that there are other loci segregating in SSC 2 of the Iberian x Landrace cross (at least for traits CW, LMA, and pH24h), showing that this chromosome still has valuable mutations to be discovered.

	Implications

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

 
We have confirmed that the IGF2-intron3-G3072A substitution is segregating in Large White and Landrace swine populations and that the A allele has an important effect in several carcass-related traits. The fact that this mutation is currently segregating at intermediate frequencies in commercial lines makes it, a priori, an ideal polymorphism to carry out marker-assisted selection. Nevertheless, we also have shown that additional loci, perhaps with opposite effects, are present on chromosome 2, and the joint gene effects along the chromosome should be taken into consideration for optimum selection responses.

	Footnotes

 
¹ This study was funded by MCYT (AGF99-0284-CO2-02) and UE (Contract No. BIO4-CT97-2243) grants. The authors thank the staff of NOVA GENÈTICA S. A. and COPAGA Coop. for cooperating in the protocol of the experiment. We are indebted to A.-S. Van Laere and L. Andersson for assistance with the IGF2 substitution genotyping. We are grateful to O. Francino and J. Dunker (Pyrosequencing AB) for technical support with the pyrosequencing technique. J. Estellé acknowledges a FPU grant from the Spanish Ministry of Education and Science (MEC), and A. Mercadé acknowledges a FI grant from the Generalitat de Catalunya.

² Correspondence—phone: 34 93 581 4260; fax: 34 93 581 2106; e-mail: Jordi.Estelle{at}uab.es.

Received for publication March 18, 2005. Accepted for publication August 11, 2005.

	Literature Cited

Top Abstract Introduction Materials and Methods Results Discussion Implications Literature Cited

 


Andersson, L., and M. Georges. 2004. Domestic-animal genomics: Deciphering the genetics of complex traits. Nat. Rev. Genet. 5:202–212.[Medline]

Bidanel, J. P., D. Milan, N. Iannuccelli, Y. Amigues, M. Y. Boscher, F. Bourgeois, J. C. Caritez, J. Gruand, P. Le Roy, H. Lagant, R. Quintanilla, C. Renard, J. Gellin, L. Ollivier, and C. Chevalet. 2001. Detection of quantitative trait loci for growth and fatness in pigs. Genet. Sel. Evol. 33:289–309.[Medline]

Bidanel, J. P., and M. Rothschild. 2002. Current status of quantitative trait locus mapping in pigs. Pig News Inf. 23:39–54.

de Koning, D. J., R. Pong-Wong, L. Varona, G. J. Evans, E. Giuffra, A. Sanchez, G. Plastow, J. L. Noguera, L. Andersson, and C. S. Haley. 2003. Full pedigree quantitative trait locus analysis in commercial pigs using variance components. J. Anim. Sci. 81:2155–2163.[Abstract/Free Full Text]

de Koning, D. J., A. P. Rattink, B. Harlizius, J. A. M. van Arendonk, E. W. Brascamp, and M. A. M. Groenen. 2000. Genome-wide scan for body composition in pigs revealed important role of imprinting. Proc. Natl. Acad. Sci. USA 97:7947–7950.[Abstract/Free Full Text]

Evans, G., E. Giuffra, A. Sanchez, S. Kerje, G. Davalos, O. Vidal, S. Illán, J. L. Noguera, L. Varona, I. Velander, O. I. Southwood, D. J. de Koning, C. S. Haley, G. S. Plastow, and L. Andersson. 2003. Identification of quantitative trait loci for production traits in commercial pig populations. Genetics 164:621–627.[Abstract/Free Full Text]

Green, P., K. Falls, and S. Crooks. 1990. Documentation for CRIMAP. Unpublished mimeo. Available: http://linkage.rockefeller.edu/soft/crimap. Accessed Mar. 31, 2004.

Hu, Z., S. Dracheva, W. Jong, D. Maglott, J. Bastiaansen, J. Reecy, and M. Rothschild. 2005. A quantitative trait loci resource and comparison tool for pigs: PigQTLBB. Plant and animal genome XIII. San Diego, CA. Available: http://www.animalgenome.org/QTLdb/. Accessed October 4, 2005.

Iannuccelli, E., N. Wolosyn, J. Arhainx, J. Gellin, and D. Milan. 1996. GEMMA: A database to manage and automate microsatellite genotyping. Page 88 in Proc. 25th Int. Conf. Anim. Genet., Int. Soc. Anim. Genet., Tours, France.

Jeon, J. T., O. Carlborg, A. Toernsten, E. Giuffra, V. Amarger, P. Chardon, L. Andersen-Eklund, K. Andersson, I. Hansson, K. Lundstroem, and L. Andersson. 1999. A paternally expressed QTL affecting skeletal and cardiac muscle mass in pig maps to the IGF2 locus. Nat. Genet. 21:157–158.[Medline]

Jungerius, B., A. S. Van Laere, M. Te Pas, B. Van Oost, L. Andersson, and M. Groenen. 2004. The IGF2-intron3-G3072A substitution explains a major imprinted QTL effect on backfat thickness in a Meishan x European white pig intercross. Genet. Res. 84:95–101.[Medline]

Malek, M., J. C. M. Dekkers, H. K. Lee, T. J. Baas, K. Prusa, E. Huff-Lonergan, and M. F. Rothschild. 2001a. A molecular genome scan analysis to identify chromosomal regions influencing economic traits in the pig. II. Meat and muscle composition. Mamm. Genome 12:637–645.[Medline]

Malek, M., J. C. M. Dekkers, H. K. Lee, T. J. Baas, and M. F. Rothschild. 2001b. A molecular genome scan analysis to identify chromosomal regions influencing economic traits in the pig. I. Growth and body composition. Mamm. Genome 12:630–636.[Medline]

Martinez, O., and R. N. Curnow. 1992. Estimating the locations and the sizes of the effects of quantitative trait loci using flanking markers. Theor. Appl. Genet. 85:480–488.

Mercadé, A., J. Estellé, J. L. Noguera, J. M. Folch, L. Varona, L. Silió, A. Sánchez, and M. Pérez-Enciso. 2005. On growth, fatness and form: A further look at porcine’s chromosome 4 in an Iberian x Landrace cross. Mamm. Genome 16:374–382.[Medline]

Nagamine, Y., C. S. Haley, A. Sewalen, and P. M. Vissher. 2003. Quantitative trait loci variation for growth and obesity between and within lines of pigs (Sus scrofa). Genetics 64:629–635.

Nezer, C., L. Moreau, B. Brouwers, W. Coppieters, J. Detillieux, R. Hanset, L. Karim, A. Kvasz, P. LeRoy, and M. Georges. 1999. An imprinted QTL with major effect on muscle mass and fat deposition maps to the IGF2 locus in pigs. Nat. Genet. 21:155–156.[Medline]

Ovilo, C., A. Clop, J. L. Noguera, M. A. Oliver, C. Barragán, C. Rodríguez, L. Silió, M. A. Toro, A. Coll, J. M. Folch, A. Sánchez, D. Babot, L. Varona, and M. Pérez-Enciso. 2002. Quantitative trait locus mapping for meat quality traits in an Iberian x Landrace F₂ pig population. J. Anim. Sci. 80:2801–2808.[Abstract/Free Full Text]

Pérez-Enciso, M., and I. Misztal. 2004. Qxpak: A versatile mixed model application for genetical genomics and QTL analyses. Bioinformatics 20:2792–2798.[Abstract/Free Full Text]

Serra, X., F. Gil, M. Pérez-Enciso, M. A. Oliver, J. M. Vázquez, M. Gispert, I. Díaz, F. Moreno, R. Latorre, and J. L. Noguera. 1998. A comparison of carcass, meat quality and histochemical characteristics of Iberian (Guadyerbas line) and Landrace pigs. Livest. Prod. Sci. 56:215–223.

Su, Y. H., Y. Z. Xiong, S. W. Jiang, Q. Zhang, M. G. Lei, R. Zheng, and C. Y. Deng. 2004. Mapping quantitative trait loci for meat quality trait in a Large White x Meishan cross. Acta Genet. Sin. 31:132–136.

Thomsen, H., H. K. Lee, M. F. Rothschild, M. Malek, and J. C. M. Dekkers. 2004. Characterization of quantitative trait loci for growth and meat quality in a cross between commercial breeds of swine. J. Anim. Sci. 82:2213–2228.[Abstract/Free Full Text]

Van Laere, A. S., M. Nguyen, M. Braunschweig, C. Nezer, C. Collette, L. Moreau, A. L. Archibald, C. S. Haley, N. Buys, M. Tally, G. Andersson, M. Georges, and L. Andersson. 2003. A regulatory mutation in IGF2 causes a major QTL effect on muscle growth in the pig. Nature 425:832–836.[Medline]

Varona, L., C. Ovilo, A. Clop, J. L. Noguera, M. Pérez-Enciso, A. Coll, J. M. Folch, C. Barragan, M. A. Toro, D. Babot, and A. Sánchez. 2002. QTL mapping for growth and carcass traits in an Iberian by Landrace pig intercross: Additive, dominant and epistatic effects. Genet. Res. 80:145–154.[Medline]

This article has been cited by other articles:

				J. Estelle, F. Gil, J. M. Vazquez, R. Latorre, G. Ramirez, M. C. Barragan, J. M. Folch, J. L. Noguera, M. A. Toro, and M. Perez-Enciso A quantitative trait locus genome scan for porcine muscle fiber traits reveals overdominance and epistasis J Anim Sci, December 1, 2008; 86(12): 3290 - 3299. [Abstract] [Full Text] [PDF]

				A. Ojeda, L.-S. Huang, J. Ren, A. Angiolillo, I.-C. Cho, H. Soto, C. Lemus-Flores, S. M. Makuza, J. M. Folch, and M. Perez-Enciso Selection in the Making: A Worldwide Survey of Haplotypic Diversity Around a Causative Mutation in Porcine IGF2 Genetics, March 1, 2008; 178(3): 1639 - 1652. [Abstract] [Full Text] [PDF]

				F. W. Zhang, H. C. Cheng, C. D. Jiang, C. Y. Deng, Y. Z. Xiong, F. E. Li, and M. G. Lei Imprinted status of pleomorphic adenoma gene-like I and paternal expression gene 10 genes in pigs J Anim Sci, April 1, 2007; 85(4): 886 - 890. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Estellé, J. Articles by Folch, J. M. Search for Related Content PubMed PubMed Citation Articles by Estellé, J. Articles by Folch, J. M.