Study On Growth And Immunity Of Whitmania Pigra Whitman In Different Light Qualities

Whitmania pigra Whitman belongs to Haemo pidae and dried W.pigra,Hirudo(Fauna Sinica,1996).It is the mainstream varieties of medicinal leeches market in China and also the main raw material of traditional Chinese medicine leech that can remove blood stasi and cure cardiovascular diseases.With the aggravation of environment pollution and the expansion of market demands,artificial breeding technology of W.pigra emerges.The current breeding model mainly dominated by "pond +cage".The growth of W.pigra tends to be more influenced by environmental factors(water quality,temperature,sunlight)that may cause the unstable production of W.pigra during the outdoor culture pattern.Therefore,there is an urgent need for exploring indoor cultivation technique of W,pigra.The light as an important ecological factor to effect the growth of W.pigra would be significant to indoor cultivation technique.Based on the previous researches,the experiment will further explore the growth and immunity of W.pigra after 45 days old under light of different light spectrum(red,white and blue)on physiological and molecular level.The results are as follows:(1)In this study,four light color treatments(red,blue,white,natural light)were tested to determine effects of light spectrum on the growth of larval W.pigra(30 days old)at the same intensity.The experiment lasted for 50 days.Results:The specific growth rate(SGR)under blue light condition was significantly higher in the first 10 days.At the end of the experiment,specific growth rate(SGR)and weight gain rate under red light condition were higher(P<0.05)than other groups.Meanwhile,the enzymes activities of digestive enzymes(protease,amylase and lipase)were higher under red light condition.However,the enzymes activities of antioxidant enzymes(SOD?CAT?AKP)were lower under white light condition compared with other treatments(P<0.05).In addition,no significant changes were observed for water content,total ash,acid insoluble ash,pH and antithrombin activity in the all treatments.Conclusion:From 50 days after rearing,the digestive enzymes and growth rate were higher under red light condition but antioxidant enzymes were higher under white light condition.Furthermore,light spectrum has no significant effect on the internal quality of W.pigra.(2)A total of 11 million distinct tags were obtained by sequencing these nine libraries.Compared with the white light library,there were 137 and 185 upregulated genes and 200 and 77 downregulated genes in blue light and red light libraries.There were 177 upregulated genes and 64 downregulated genes in red light libraries when ompared with the blue light library,respectively.Trend analysis of these differentially expressed genes identified many statistically significant trends.(3)In order to analysis the molecular effects of light quality on growth and immune regulation mechanism of W.pigra,we detected the gene expression of SOD,CAT,AKP,HK,LP,PT,GH,IGF-1,MAPKs and PPase of W.pigra at 30-60 day of age.We find that the immune gene expression of W.pigra in white light is the highest of the three light conditions which matches well with the antioxidant enzyme activity.The growth and digestive enzyme gene of W.pigra under red light condition is significantly higher than those under the white and blue condition.Red light enhance protease and lipase gene expression of W.pigra after 40 days of age while blue light inhibits the expression.Full spectrum can enhance the expression of immune genes of W.pigra,however single light quality is not conducive to immune function.