책임운영기관 농촌진흥청 국립축산과학원 (로고)

Native pig breeds are very important for conservation and may contain valuable genetic variants for adaptation1. The Jeju native pig (JNP) has superior characteristics such as a reddish meat color (a*) and high intramuscular fat (IMF) content. Previous results showed that a functional sequence variant (FSV) in the porcine MYH3 (g.-1805_-1810, ACGT) gene in the promoter region affects the ratios of myofibers and is clearly associated with IMF and a*2. Myoglobin (Mb) is known to be the main protein affecting meat color, especially the a* trait3. Mb occurs in three types that differ in oxidation&#8211;reduction states: deoxymyoglobin (DeoxyMb), oxymyoglobin (OxyMb), and metmyoglobin (MetMb), corresponding to the purplish-red, bright cherry-red and brown colors, respectively 4. This study investigates the endophenotypic effects of an FSV in the MYH3 gene on the Mb oxidation&#8211;reduction states in four different porcine muscles (longissimus dorsi, semimembranosus, biceps femoris and triceps brachii) using crossbred offspring from Landrace and JNP. Using PCR-RFLP, we measured the MYH3 FSV genotypes QQ, Qq, and qq (Table S1, Figure S1; Q and q are the JNP and Landrace variants, respectively). Chi-square test results revealed that this variant is not in Hardy&#8211;Weinberg equilibrium (p<0.05), indicating selection pressure favoring QQ (Table S2). The results also indicate that QQ genotype of the MYH3 FSV is associated with OxyMb contents but lower DeoxyMb and MetMb contents, which in these animals results in reddish-colored meat (Table 1, Figure S2). The OxyMb contents in longissimus dorsi (p<0.001) and semimembranosus muscles (p<0.05) of QQ animals with the QQ genotype is significantly higher than in the same muscles of qq animals. Conversely, in the same muscle types of qq animals the DeoxyMb contents is higher than observed in QQ animals (p<0.001 and <0.05, respectively). For MetMb, significantly high values were only observed in the longissimus dorsi muscle in qq animals. However, the biceps femoris and triceps brachii muscles did not show a significant associations of different DeoxyMb, OxyMb, and MetMb contents with the FSV genotypes, which indicates that different muscles have different ratios of fiber types. We conclude that the Mb oxidation&#8211;reduction state is an endophenotype that controls meat color and thus an important meat quality trait. It is associated with the MYH3 promoter variants, which via selective breeding may be used for the meeting consumers’ demands.