The Appropriate Level Of Tryptophan For Apis Mellifera Worker Bee Larvae And Adult Feed

Tryptophan is one of the ten essential amino acids for honeybee and, it has an important role in honeybee drone larva growth and development, it is also the indispensable nutrients for worker bees, which can affect their performance, growth and development, and so on. Exploring the appropriate tryptophan levels of feed for honey bee larve(or adult) is good for keeping honey bee scientifically and healthily.This larvae test is designed to study the appropriate levels of tryptophan in Apis mellifera worker bee larvae feed,and provide a theoretical basis for the nutritional needs of tryptophan. 1008 one-day-old larvaes were randomly divided into seven groups of three replicates of 48 larvaes, and were fed different diets with tryptophan at the levels of 7.84 mg/g, 8.84 mg/g, 9.84 mg/g, 10.84 mg/g, 11.84 mg/g, 12.84 mg/g and 13.84 mg/g respectively. 5-day-old worker bee larvaes were used for measuring TPH(Tryptophan hydroxylase,TPH) gene and 5-HT receptors(5-hydroxytryptamine receptors, 5-HTR)1,2α, 2β, 7 gene expression. Take 6-day-old worker bee larvae as samples for determining total protein content, MDA, T-AOC, and 6-day-old larval hemolymph was taken to be used for measuring the level of free tryptophan. The pupation rate was calculated at 7 days old. Deposition amount of tryptophan was analysed using 9-day-old pupa, and the worker bee eclosion rate was calculated at 21 days old. Pupation rate and larvae total protein content at 6 days old, tryptophan deposition at 9 days old pupa and worker bee eclosion rate at 21 days old were highest when the tryptophan level was10.84 mg/g(P<0.05). The expressions of TPH, 5-HT receptors 1,2α and 2β genes of larvae at 5 days old and hemolymph free tryptophan content of larvae at 6 days old were elevated significantly by 10.84-11.84 mg/g tryptophan(P<0.05). However, 5-HT receptor 7 gene expression of 5-day-old worker bee larvae and MDA level of 6-day-old worker bee larvae fed 12.84-13.84 mg/g tryptophan were higher than worker bee larvae fed 7.84-11.84 mg/g tryptophan(P<0.05). Dietary supplied with 10.84-13.84 mg/g tryptophan improved significantly 6-day-old worker bee larvae T-AOC compared with dietary with 7.84-9.84 mg/g tryptophan(P<0.05). To sum up, we analyze the indicators of Physiology, biochemistry and molecular biology. We make the fitting curves of 6-day-old larvae total protein concentration, 9-day-old pupa tryptophan deposition rate, larvae pupate rate, larvae eclosion rate and the relative expression levels of 6-day-old larvae TPH gene. After calculations and analysis, we concluded that the appropriate level of tryptophan for Apis mellifera worker bee larvae is 9.85-11.34 mg/g.This research is designed to study the appropriate levels of tryptophan in Apis mellifera worker bee adult, and provide a theoretical basis for the nutritional needs of tryptophan. The worker bees were randomly divided into seven groups of three replicates of 100 worker bees, and were fed different diets with tryptophan at the levels of 9 mg/g, 10 mg/g, 11 mg/g, 12 mg/g, 13 mg/g, and 14 mg/g respectively. 6-day-old worker bees were used for measuring the total protein concentration, MDA contentration, 5-HT contentration, and the transcription levels of TPH, 5-HT1 R, 5-HT2αR, 5-HT2βR, 5-HT7 R gene. In addition, we had measured the hypopharyngeal gland acinus size of 8-day-old worker bees, the Tryptophan deposition of 12-day-old worker bees, feed intake, weight, and survival rate and so on. The 6-day-old worker bee concentration of 5-HT, the 6-day-old worker bee relative expressions of TPH and 5-HT1 R gene were highest, the 8-day-old worker bee hypopharyngeal gland acinus size, the 12-day-old worker bee tryptophan deposition, the survival rate of worker bees, when the tryptophan level was 12 mg/g(P<0.05). The relative expressions of 5-HT2βR gene were elevated significantly by the tryptophan levels of 10-12 mg/g. The relative expressions of 5-HT7 R are moderate, when the tryptophan levels were 9-13 mg/g(P<0.05). The concentration of MDA is low when the tryptophan levels of 9-12 mg/g(P<0.05). There was no significant differences between different tryptophan levels, about the weight of 6-day-old and 12-day-old worker bees(P>0.05). To sum up, we analyze the indicators of Physiology, biochemistry and molecular biology. We make the fitting curves of 6-day-old worker bee total protein concentration, 12-day-old woker bee tryptophan deposition rate, the relative expression levels of 6-day-old woker bee 5-HT2α gene and the relative expression levels of 6-day-old woker bee 5-HT2β gene. After calculations and analysis, we concluded that the appropriate level of tryptophan for Apis mellifera worker bee is 10.75-11.52 mg/g.Studies show that tryptophan can influence the physiological and biochemical indices related with growth of Apis mellifera worker bee larve and adult. The appropriate level of tryptophan for Apis mellifera worker bee larvae feed is 9.85-11.34 in mg/g, the appropriate level of tryptophan for Apis mellifera worker bee adult feed is 10.75-11.52 mg/g.