Correlation Analysis Between Single-Nucleotide Polymorphism of Malate Dehydrogenase Gene 5′-Flanking Region and Growth and Body Composition Traits in Chicken

Malate dehydrogenase (MD) is a key enzyme that plays an important role in energy metabolism. It catalyzes the oxidative decarboxylation of L-malate to yield CO₂ and pyruvate, while simultaneously generating NADPH from NADP⁺. The NADPH generated can be utilized in de novo synthesis of palmitate, which is the precursor molecule for the formation of other long-chain fatty acids. And high levels of MD will also activate muscle development. The current study was designed to investigate the effects of MD gene on growth and body-composition traits in chicken. The eighth generation population of Northeast Agricultural University broiler lines divergently selected for its abdominal fat and Northeast Agricultural University F₂ resource population were used in the research. Polymorphisms were detected by DNA sequencing and PCR-RFLP method was then developed to screen the population. A single mutation at the position of the 235 bp (Accession No. U49693) of MD 5′-flanking region was found. The correlation analysis between the polymorphism of the MD gene and growth and body composition traits was carried out using the appropriate statistic model. Least-square analysis showed that the BB genotype birds had much higher pectoralis major weight and percentage of pectoralis major than AA genotype birds (P<0.05). The abdominal fat weight, percentage of abdominal fat, the liver weight and percentage of liver weight of the AA genotype birds were much higher than those of BB genotype birds (P<0.05). These results indicate that MD gene is the major gene or is linked to the major gene that affects the growth and body composition traits in chicken.