Investigation On Colonization Of Gut Microbial Of The Honeybees(Apis Cerana And Apis Mellifara)

Apis cerana and Apis mellif era as the two largest commercial species of bee in China not only produce an abundance of bee products with a huge economic value,but also provide pollination services for crops.Therefore,healthy breeding of bees is always concerned.In recent years,bees have been subjected to various biotic and abiotic stress,resulting in major ecological challenges for their health.Previous studies have demonstrated a closed relationship of gut microbe with host,showing important roles of gut microbe in food metabolism,health,disease,immunity and development in the host.The function of gut microbe strongly depends on structure of gut microbe,and colonization of gut microbe is a basis of structure formation.However,it is still little known about the colonization of the gut microbe in A.cerana and A.mellifera species widely cultivated in China.Furthermore,researchers reported that colonization of the gut microbe in A.mellifera was performed within 7 day after leaving hive.Despite previous studies collected samples to explore 7-day colonization dynamics in A.mellifera,time span of sampling workers was large,which may caused the incompleted information about processes of gut microbe colonization.Therefore,to better understand change dynamics of the gut microbe a of bees in colonization during the period of the colonization,A.mellifera workers were collected every 12 hours after they left the hive.A high-density sampling was conducted across the colonization of the gut microbe.Meanwhile,this study also collected the A.mellifera and the A.cerana as the research object.The High-throughput sequencing technology was used to systematically study the succession law of the gut microbe of the two kinds of bees under natural and healthy conditions on a long time scale.To reveal the dynamic succession law of the gut microbe of the honey bee under the same ecological conditions.The main results are as follows: 1.To explore the colonization dynamics of the gut microbe in A.mellifera during the period of colonization based on high-density sampling The results showed that diversity and variation with peh(post-emergence-hours,peh)in the gut microbe of the workers: the diversity of the gut microbe was the highest at 0 peh,and the change ranges of the gut microbe was the highest at 0 peh-24 peh,and then gut microbe a tended to be stable.In this study,132 OTU were found to be shared by the gut microbe before and after colonization,indicating that these 132 OTU were core in the gut microbe of A.mellifera.In addition,this study also foundan increasing relative abundance in these core flora,accompanied by a decrease of that in non-core flora.Moreover,an increasing relative abundance of core flora was closely correlated with a decreasing that of non-core flora(Pearson correlation coefficient = 0.891,p < 0.01).2.Colonized dynamics of the gut microbe of A.mellifera across different developmental stages In this study,the results showed that the core gut microbe in the workers was significantly changed with individual developments from 0-40 days.The core gut microbe,including Gilliamella,Frischella and Snodgrassella,is already starting to significantly appear at 1 dpe.Lactobacillus,Bif idobacterium and Commensalibacter appeared at 3 dpe with the significant decrease of the relative abundance of Gilliamella.The signif icant appearance of Lactobacillus kunkeei and Bartonella at 12 dpe,accompanied by a signif icant decrease of the relative abundance in Lactobacillus helsingborgensis.In addition,the diversity of gut microbe was changed signif icantly with the host aging.3.Colonized dynamics of the gut microbe of A.cerana across different developmental stages High-throughput sequencing was employed to detect colonized dynamics of the gut microbe of A.cerana across different developmental stages.The results showed that the diversity of the gut microbe was changed significantly with the host aging.With colonization processes,at phylum level,the relative abundance of Proteobacteria(p = 0.013),Firmicutes(p = 0.008)and Bacteroidetes(p = 0.021)was significantly altered;at genus level,the relative abundance of Lactobacillus(p = 0.003),Gilliamella(p = 0.011),Apibacter(p = 0.006),Bif idobacterium(p = 0.026)and Acinetobacter(p = 0.005)was also significantly altered.In addition,the results of Lef Se(effect size measurements)analysis(LDE≥4)showed a significant impact of environmental exposure on the constructure of the gut microbe at early stage(0-1 dpe)of the development of workers.At 0 dpe and 1 dpe,it has been appeared enriched bacterial groups that their relative abundance gradually decreased with the development of workers.