| Melatonin, N-acetyl-5-methoxytryptamine, secreted by the brain cells in honeybees, is a typical photoperiodic signal neuron-hormone. It's widely distributed over lots of living organisms as different as prokaryotes and vertebrates, even in plants. We tested the worker's melatonin in Apis mellifera ligustica Spinola of different behavior developments by RIA (radioimmunoassay) method. It showed some correlation between melatonin, the worker's age, and the worker labor division, and there were a melatonin daily rhythm and a year rhythm of the work bees. Following is the results:1. It showed that the melatonin concentration is related to the age of worker bees. The melatonin concentration was higher from the forager with 21 days compared with the other ages. The highest melatonin level came from 21 days' bee (213.14 pg/bee) and the lowest level was 1 day's bee (6.08pg/bee), the fomer's was grossly 35times higher than the latter"s.2. The melatonin concentration is related to the worker labour division. The melatonin concentration in foragers was higher compared to younger bees. The highest melatonin concentration of pollen collector was 404.12 pg/bee and the lowest was the nurse bees of 113.1pg/bee, the fomer's was 30 times higer than the latter's.3. The melatonin concentration from worker bees showed a daily rhythm: the highest level appeared at 7:20am and 19:20pm, the melatonin level was 167.16pg/bee and 123.83pg/bee respectively; the lowest level was 26.27pg/bee appeared at 1 : 20am, the fomer"s was 6.36and4.715times higher than the latter"s.4. The melatonin concentration from worker bee changed with month. The highest concentration from foragers appeared at March and October; the concentration matained a steady level from March to October for the non-foragers. The melatonin levels were relatively lower from November to next year's Feburary for different kinds of bees. |
