| Phenotypes of organisms are not only determined by completely genetically, but are also flexible according to environmental factors. The caste determination in honeybees is one of the most typical forms of the insect polymorphisms. The queen and worker have similar growth rates but differ greatly in their morphology, physiology, function and developmental timeline. There was no doubting that the honeybee caste determination is driven by non-genetically factors, which are the environmental factors. Across the ontogenetic development of honey bee queens and workers, they are differed in living space. Further, the nutrients differences between queen and woker larval foods is the key element that inducing honey bee caste determination. In recent years, great progressed have made in the fields of nutritional and spatial factors on caste determination, but the mechanisms of these factors remain unclear.In this study, we explored the diversity in life history of queen and worker honey bees(Apis mellifera L.) and the comparison of the nutrient compositions of royal jelly and worker jelly of honey bees (Apis mellifera L.), the effects of nutritional and spatial factors on honey bee caste determination on the differences in quality of royal jelly between Apis mellifera carnica and Apis mellifera ligustica, the influence of bee feeding with honey or nectar substitutes on RJ quality under honey-feeding, sucrose-feeding and honey-sucrose changing feeding conditions. Further, we hypothesized that the spatial factors act as starvation effects on the worker caste determination. We set up a larval-weight-depending model of honeybee caste determination in vitro to explore the spatial factors-starvation effects on the caste determination of honey bees. The main results were as follows:1. In this study,5 colonies (Apis mellifera L.) were chose to examine the differences between queen and worker larvae during their ontogenetic development. The life history of queen and worker bees was characterized, and reference pictures are provided. The queen and worker larvae reach their peak weight at the same day. The living space of queen larvae is 5 fold larger than worker. Furthermore, the queen larvae have a shorter development time than worker larvae. The developmental rate of workers was found to differ as much as 3 days, even if the two types of bees were laid within 12 hours of each other. We also present some interesting phenomena with regards to the developmental stages of queen and worker bees.2. The chemical compositions, minerals and trace elements of royal jelly (RJ), worker jelly (WJ) and royal jelly on particular days (Only-2-day RJ (O2d), Only-3-day RJ (O3d) and Only-4-day RJ (04d)) were determined. Significant differences were found between the RJ and WJ samples for moisture, protein,10-HDA, fructose (F) and glucose (G). The samples on 02d contained significantly higher nutrients than the 03 d and 04d samples. The results of this study add to the current knowledge of the nutritional values of RJ and WJ. These results also imply that there must be a strong relationship between nutritional effects and polyphenism in honey bees.3. Royal jelly (RJ) is known for its unique effects on human health. Over the past century, the composition of RJ has been studied by numerous researchers. However, the influence of bee feeding with honey or nectar substitutes on RJ quality is less well known. This study was conducted to evaluate the effects of three different feeding protocols on RJ quality. RJ samples were specifically obtained after honey feeding, honey-sucrose feeding or sucrose feeding; these RJ samples are named HR, HSR and SR, respectively. The results show that the proximate composition and macro-and trace element content of the HR samples were similar to those of the HSR and SR samples. Furthermore, the results showed that the stored feed obtained from sealed combs after sucrose feeding had similar levels of fructose, glucose and sucrose as the feed obtained from sealed combs after honey feeding. However, a significantly higher sucrose content was found in the stored feed obtained from unsealed combs after sucrose feeding. In conclusion, sucrose feeding and honey-sucrose feeding had little influence on the quality of RJ.4. The influence of bee feeding with honey or nectar substitutes on RJ quality is less well known. This study was conducted to evaluate the effects of three different feeding protocols on RJ quality. RJ samples were specifically obtained after honey feeding, honey-sucrose feeding or sucrose feeding; these RJ samples are named HR, HSR and SR, respectively. The results show that the proximate composition and macro- and trace element content of the HR samples were similar to those of the HSR and SR samples. Furthermore, the results showed that the stored feed obtained from sealed combs after sucrose feeding had similar levels of fructose, glucose and sucrose as the feed obtained from sealed combs after honey feeding. However, a significantly higher sucrose content was found in the stored feed obtained from unsealed combs after sucrose feeding. In conclusion, sucrose feeding and honey-sucrose feeding had little influence on the quality of RJ.5. We hypothesis that the worker cell limits the development of worker larvae, which resulting the weight of worker larvae are less than queen in the last star. This spatial limitation plays a part as starvation. According to the weight of queen and worker larvae in natural colony, we set the honey bee caste determination model:Starvation group and Feeding group. Starvation group were the larvae which at the weight of 160-180mg, and the Feeding group were the larvae which weight above 320mg.The pupation rate and survival rate were closely related to larval weight, larvae weight above 160mg-180mg had the highest pupation rate and survival rate, which meaning that the critical weight of worker is around 160mg. Starvation significantly introduced the honey bee caste determination:larvae starved at 160 to 180mg mature into worker-like caste, and the larvae fed above 320mg were mainly mature into queen-like caste. Starvation significantly influenced the ontogenetic development of starved and fed larvae. Starvation didn’t delay the onset of metamorphosis, but formed small adults. Larvae starved at 160mg needed 109h to metamorphosis. Body size is closely related with peak larval weight:individual body weight of starved and fed larvae were the same as natural worker and queen, respectively. Morphology of starved and fed individual were the same as natural worker and queen, respectively. Starvation significantly influenced the ovaries development. Compared to starved larvae, the lower levels of AmInR-2 and AmHr4 mRNA were found in fed larvae during the feeding time, and they were higher when fed larvae stop growth. AmTOR mRNA in fed larvae were lower than starved larvae, but significant differences were only found at 48h,60h,72h and 96h。AmHR4 mRNA expression was sensitive to starvation, and this gene may play a key role in the regulating mechanism of spatial factors on honey bee caste determination.In conclusion, Nutritional and living space factors are the two critical factors on the caste determination of honey bees. Nutritional variances of WJ and RJ resulted in the growth rate differeces between queen- and worker-larvae; the considerable variation in the size of living space induced the weight of queen larvae are significantly higher than worker larvae. There is a two-critical weight-determination mechanism in the caste determination of honey bees: Under the interaction of nutritional and living space factors, the larvae which weight among 160-180mg would develop into worker-like individuals and the larvae above 320mg would develop into queen-like individuals. |
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