부산대학교 도서관

L-Leucine is an important factor for growth and development in animals. However, very little is known about the nutritional role and physiological function of L-leucine in honeybees. In this study,we determined the effects of Lleucine supplementation on protein synthesis and amino acid balance in honeybee larvae. First instar larvaewere fed different L-leucine diets (6.45, 8.45 and 10.45 mg/g) during the entire larval stage. After the larvae egested urate crystals, we analyzed the protein and amino acid metabolism indexes in the larvae. There was little effect of L-leucine on larval body weight and body protein content, but the hemolymph protein concentrations were higher in 8.45 and 10.45 mg/g groups than 6.45 mg/g group. Compared to the 6.45 mg/g group, L-leucine significantly increased the contents of Ala, Leu, Lys and Met in 8.45 mg/g group and continued to be increased in 10.45 mg/g group. L-Leucine affected many TOR signaling pathway- and L-leucine metabolism-related genes, including tor, 4Ebp1, bcaat et al. Moreover, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH) activities as well as the triglycerides (TG), total cholesterol (TCHO), uric acid (UA) and urea nitrogen (URER) contents in haemolymph were significantly different among treatments. These results suggested that many factors involved in the metabolism of L-leucine and larval hemolymph play important roles in honeybee protein synthesis and amino acid balance.