Interactions between genes involved in growth and muscularity in pigs: IGF-2, myostatin, ryanodine receptor 1, and melanocortin-4 receptor

Abstract

In the swine breeding industry, two economical traits are of particular importance in sires, namely, muscle growth and average daily gain (ADG). These traits are quantitative, which implies that they are under the control of multiple genes. Mutations in these genes, associated with either muscularity or growth, are useful quantitative trait nucleotides (QTN) for unraveling genetic variation of these traits and can be used in marker-assisted selection. Until now, QTN involved in muscle growth and/or ADG in pigs were identified in porcine ryanodine receptor 1 (RYR1), insulin-like growth factor-2 (IGF-2), and melanocortin-4 receptor (MC4R). Recently, a fourth possible QTN was found in porcine myostatin (MSTN). All four QTN have an influence on muscle growth and/or somatic growth, so an influence of one mutation on one or more of the other mutations should not be excluded. However, although the polymorphisms in the RYR1 and the MC4R gene affect the function of the respective protein, the polymorphisms of the IGF-2 and MSTN gene influence the mRNA expression of the respective gene. Therefore, this study investigated possible interactions between the genotypes of MSTN, IGF-2, and MC4R (population 1) or the RYR1, IGF-2, and MSTN QTN (population 2) on IGF-2 and MSTN expression in different muscle types in pigs. In both skeletal muscle and heart muscle growth, the IGF-2:MSTN ratio seems to play an important role. Also, the RYR1 genotype had a significant effect on IGF-2 expression in m. longissimus dorsi. No effect of the MC4R QTN could be seen.

Expression levels of candidate genes for intramuscular fat deposition in two Banna mini-pig inbred lines divergently selected for fatness traits

“…The interaction between melanocortins and their receptors in the hypothalamus is one of the main neuroendocrine pathways controlling energy balance (Yeo et al , 2000; Wardlaw, 2001). However, some studies have indicated that these genes could also be expressed in the muscle tissue (Stinckens et al , 2009; Li et al , 2010; Larkina et al , 2011; Tyra et al , 2011). Our data show that the mRNA and protein abundance of LEPR and MC4R in the fat BMIL was lower than in the lean BMIL.…”

“…Genetic variants of the leptin receptor (LEPR) and the melanocortin 4 receptor (MC4R) genes were reported to be associated with IMF deposition (Mackowski et al , 2005; Ovilo et al , 2005; Bruun et al , 2006; Jokubka et al , 2006; Kim et al , 2006; Piórkowska et al , 2010; Fan et al , 2009, 2010; Li et al , 2010; Switonski et al , 2010). Although LEPR and MC4R are mainly studied in hypothalamus, some reports indicated that they could be expressed in muscle tissue as well (Stinckens et al , 2009; Li et al , 2010; Larkina et al , 2011; Tyra et al , 2011). Global genomics analyses also led to the hypothesis that IMF deposition could be affected by both lipid metabolism and energy metabolism (Liu et al , 2009; Cánovas et al , 2010).…”

Effects of different dietary intake on mRNA levels of MSTN, IGF-I, and IGF-II in the keletal muscle of Dorper and Hu sheep hybrid F1 rams

“…As a result, it was hypothesized that the ratio of mRNA concentrations between MSTN and IGFs might serve as indicators of muscle mass (Stinckens et al, 2009). In this study, we determined the expression patterns of MSTN and IGF genes in the skeletal muscle of sheep.…”

The MC4R c.893G>A mutation: A marker for growth and leanness associated with boar taint odour in Belgian pig breeds

“…The quantity (on average 321.9 ± 44.0 ng/μl) and quality (260/280 ratio between 1.5 and 2) of the obtained DNA were measured using UV-spectrophotometry (Implen GmbH, München, Germany). For analysis of the c.893G N A substitution in MC4R found by Kim et al (2000), forward primer 5′-TTACTCGCCTCAATTTGCAGC-3′ and reverse primer 5′-ACAAATCACAGAGGCCACC-3′ were used for amplification as described by Stinckens et al (2009). Digestion of the resulting PCR product with TaqI (Thermo Fisher Scientific Inc., USA) was carried out using standard conditions.…”