Vergleichende Analyse des Kohlenhydratstoffwechsels bei den Kasten der Honigbiene, Apis mellifera

Abstract

Enzymatic activities of ALD ∗ ∗ For abbreviations see page 1252. , GAPDH, GDH, G-6-PDH, HK, LDH, PGK, PGluM, Ph a+b, and TIM have been determined in the 100,000 g supernatant of a total extract from both castes of the female honey bee. Data are given for the larval, pharate pupal, emerged pupal, and adult stages. The amount of glycogen, glucose, fructose, glucose-6-phosphate, fructose-6-phosphate, lactate, pyruvate, α-glycerophosphate, and of total lipid has been measured. These studies have been accomplished as a contribution to the understanding of the metabolic action of the determining substance contained in royal jelly, which is responsible for queen bee formation. In both castes aldolase activity is increased about twentyfold in the pharate pupa compared with the values of the larval stages. The activity then continuously drops to the newly emerged adult, which contains about 20 per cent of the maximum activity. A similar course is found in the case of phosphorylase. The activities of all the other enzymes follow a more or less U-shaped curve with high levels in the larvae and newly emerged adults. In the pupae the following minimum values of specific activity are reached (per cent of maximal activity): ALD 20, GAPDH 40, GDH 30, G-6-PDH 20, HK 30, LDH 30, PGK 30, PGluM 15, TIM 35. As a difference between both castes, an abrupt drop of several enzyme activities is seen in the worker bee between the larval and pharate pupal stage towards a level lower than that of the queen pupa (TIM, HK, GDH, LDH). The proportion of GDH LDH points to a more aerobic carbohydrate metabolism in the queen than in the worker. The accelerated development of the queen corresponds to a high activity of PGluM, HK, and TIM. The enzyme patterns in queens and workers follow the same endogenic rhythm dependent on the stage and not on the duration of adult development. The influence of the determining substance is more pronounced at the substrate level. After the sensible phase of determination glycogen concentration drops in the 4-day-old queen larva to a low level of about 5 mg/g fresh wt., which is rather constant in the further stages. The worker builds up a high amount of glycogen with a maximum of about 50 mg/g in the white-eyed pupa. This storage decreases continuously and attains the same low level in the newly emerged adult as the queen caste. Similar results are shown by the determination of total lipids, with values of about 10 mg/g in the queen pupa and about 40 mg/g in the worker. In both castes α-glycerophosphate, pyruvate, and lactate are enriched during larval development. In the following pupal stage all metabolite levels are lowered. The concentration of α-glycerophosphate during larval and pupal development is about 50 per cent higher in the queen than in the worker. During diapause lactate concentration is about twofold higher in the queen.