| 10-Hydroxy-2-Decenoic acid(10-HDA),which is secreted by bees mandibular glands(MGs),is a kind of unsaturated fatty acid and the main bioactive substances of royal jelly.10-HDA which is widely used in pharmaceutical care and cosmetic products has a variety of physiological functions,such as adjusting immunity,lowering blood lipids,antibacterial and so on.10-HDA is in great demand on the market,but it accounts for a lower proportion in royal jelly.Therefore,the realization of 10-HDA industrialized production has become the focus of attention for researchers.However,we must firstly understand the specific biosynthetic mechanism of 10-HDA in order to realize the industrialization of that,but it is not clear currently.It had been identified that ETF-? and KAT might be related to the biosynthesis of 10-HDA by using the methods of proteomics.As the raw material of the colony,the local domestication of Italian bees(Apis mellifera ligustica)was studied to analyze the expression patterns of KAT and ETF-? genes in different tissues and different ages of worker bees.The relationships between ETF-? and KAT and the 10-HDA biosynthetic pathway in honeybees were analyzed by adding medium-and long-chain fatty acids into the basal diet and RNA interference.It was in order to explore the biosynthetic pathway of 10-HDA and to reveal the molecular mechanism of 10-HDA biosynthesis.The expression levels of ETF-? and KAT were detected by the technologies of semi quantitative RT-PCR and RNA interference.The results suggested that ETF-? and KAT were high expressed in the MGs of honeybees,and the expression patterns of ETF-? and KAT were different in different day ages,which were consistent with the secretion peaks of 10-HDA.Also the contents of 10-HDA were detected by HPLC.The results showed that the pollen feed which is added different concentrations of medium-and long-chain fatty acids could improve the production of 10-HDA to a certain extent.And compared with the control group,the effects of 5% stearic acid and 1% decanoic acid were more significant(P<0.05).The secretions of 10-HDA for the bees in 5,10,15 day old were increased by 84.65%,26.65% and 56.66% respectively in 5% stearic acid group,while increased by 41.04%,52.6%,41.05% in 1% decanoate acid group.At the same time,the secretion peaks of 10-HDA were ahead after adding two kinds of fatty acids,which are from 20 days in advance to 15 and 10 days.These may be achieved in the short term to improve the yield of 10-HDA.And it provides theory basis for further revealing the biosynthesis mechanism of 10-HDA,and provides the possibility for the realization of 10-HDA in mass production.In addition,ETF-? and KAT m RNA levels for bees before the age of 15 were up-regulated by feeding stearic acid and decanoic acid,and its increasing trend was the same as that of 10-HDA in the body of bees.Moreover,after knocking out ETF-? and KAT by RNAi,the productions of 10-HDA were decreased and the surface of the worker bee GMs appeared to be wizened and loose.It speculated that ETF-? and KAT were likely to have involvement with the synthesis of HDA in the MGs of bees,and it laid the foundation for further improvement of the 10-HDA biosynthetic pathway. |
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