Effects Of Nosema Ceranae On Behaviors,Immune Gene Expression And Haemolymph Sugar Levels Of Apis Cerana

Nosema ceranae is a chronic parasite of eastern honey bees,Apis cerana cerana,in their digestive systems.This parasite can affect physiology,behavior,health and longevity of honey bees,and it may alter the labor division of worker bees,organizational behavior,and population of colonies.The infected bees can be more sensitive to sugar and even more difficult to perform trophallaxis with other bees.In recent years,there is a tendency that Nosema ceranae has gradually replaced Nosema apis and become the main parasite of western honey bees,Apis mellifera.It is considered to be one of the main factors leading to Colony Collapse Disorder(CCD).Nosema ceranae has been widely studied and has drawn great interests for its impacts on the new host,western honey bee.By contrast,it is relatively limited for its original host Asian honey bees.Workers of Apis cerana cerana were infected by Nosema ceranae isolated from Apis cerana cerana.We can analyze the impacts of Nosema ceranae on the health of Apis cerana cerana through the observation to the behavior,expression of immune gene and the sugar content in the haemolymph.1、Workers of Apis cerana cerana were inoculated by spore solutions with different number(103,3x 103,104,3 x 104,105)and the infection rate and mortality were recorded.The results showed that there was a significant positive correlation between the spore concentration and its impacts on the lifespan of workers.We found that the concentration of spores at 105 caused the highest infection rate 100%.This investigation laid the foundation for the study of the impacts of Nosema ceranae on Apis cerana cerana.2、We infected workers of Apis cerana cerana by spore solution with 105 and analyzed non-associative learning(habits and sensitization),associative learning and memory,and proboscis extension response to a range of concentrations of sucrose solution.We attempt to assay the impacts of Nosema ceranae on the behavior of Apis cerana cerana.The results suggested that the infected bees were more responsive to sucrose solution,and there was a significant difference at the concentration of 10%,50%compared with control group.In addition,the memory rate of the treatment group is significantly higher than control group after 2 hours in terms of associative learning train.3、The expression levels of immune genes,including vg,abaecin,apidnt,del,de2 and eater,were detected using infected and uninfected bees and we tested whether Nosema ceranae could cause immune response.The expression levels of hymen and de2 in treatment group was significantly higher than that in control group.This indicated that Nosema ceranae can affect the expression of immune genes,and then initiate immune response capability of Apis cerana cerana.4、By HPLC analysis,the quantitative analyses were performed with the haemolymph of the infected and treatment group of Apis cerana cerana by Nosema cerana.Under the same conditions of HPLC set previously,the concentrations of trehalose and glucose in the haemolymph were further examined.The results showed that the sugar content in haemolymph had no significant difference.Therefore,Nosema ceranae did not effect on the blood sugar of Apis cerana.