The Effect Of Proanthocyanidins On The Senescence And Population Of Brachionus Calyciflorus

The rotifer Brachionus calyciforus Pallas is a member of the Brachionidae,Ploima,Monogononta,Rotifer.The life history has the phenomenon of heterogenesis.In recent years,because of its small body size(about 300?m),shorter generation times(5-7 days),easy for culture and obvious characterization of aging,it is considered as a potential model organism for aging research.Proanthocyanidin(PC)is a mixture of polyphenols which widely exists in the plant,it has strong ability of scavenging free radicals and antioxidant.It is a kind of material which has attracted more attention in the study of anti-aging in recent years.In this paper,three different experiments were designed for the study of common freshwater rotifer(Proanthocyanidins and temperature disposes B.calyciflorus independently.Combined action of proanthocyanidins and temperature disposes B.calyciflorus,Proanthocyanidins and temperature disposes B.calyciflorus,then observing their offsprings).The purpose of this study is to explore the reaction rules of individual and population of B.calyciflorus under the action of proanthocyanidins and temperature,explore the influence of two exogenous factors on Rotifer aging,so as to provide theoretical basis for promoting 5.calyciforus as a model animal for aging research.Meanwhile,through two exogenous factors,we discussed the potential effect of exogenous substances on the production of rotifer.Main results of this dissertation Included the following parts:1.Effects of different concentrations of PC on the aging and population of B.calyciflorusThe experimental temperature is 25±1?,light 40001x,and day length ratio(L:D)16:8,set control group(0?g/mL)and 0.2,0.4,0.8,1.0?g/mL four experimental groups.The results showed that,the average lifespan of B.calyciflorus is 167.5± 1.32h in the control group.The lifespan of rotifers increases with the proanthocyanidin concentration decreased,but more than a certain concentration may be suppressed.The group in 0.4?g/mL extended the rotifer's lifespan to 195±4.82h,16.77%obviously more than the control(P<0.05);when the concentration arrived 1.?g/mL,life was restrained to 132±3.12h,compared with the control group,it was significantly shortened by 21.19%.Proanthocyanidin also affected the reproduction and population of B.calyciflorus,but no effects on the pregenital period of rotifer.The low concentration of proanthocyanidins could postpone the reproductive peak of about 12h,but had no effect on the total reproduction;high concentration of proanthocyanidins significantly reduced the offsprings of the rotifer,which was about 20%less than the control group.The proper concentration of PC can speed up the growth of the population and expand the capacity of its population.In this dissertation,0.8?g/mL group had the best effect,the population growth was obviously accelerated,and the capacity of the population increased about 25%.2.Effects of different temperatures on aging and population of B.calyciflorusThe experimental light 40001x,day length ratio(L:D)16:8,set three temperature(20?,25? and 30?).As the results,in 25?,the lifespan of the rotifer was 166.5±5.27h;in 20?,the lifespan was obviously extended to 209±1.32h,longer about 25.53%than what in 25?(P<0.05),but the reproduction was not affected significantly.There was no significant effect on the survival and lifespan of the rotifer at 30?,but the reproductive peak of the rotifer was obviously advanced(about 24h)and the offsprings of the rotifer decreased significantly.Studying the effects of temperature on the population of the rotifer,we found that the optimum growth temperature of B.calyciflorus is about 25?,the population of rotifer was at the peak of the sixth day,and the maximum density of the population was about 80 ind./mL.When the temperature was reduced to 20?,the time for the population to reach the maximum density was postponed,and the maximum population density was relatively reduced,with about 60 ind./mL.When the ambient temperature exceeds a certain limit(30?),can accelerate the growth of the population,but the largest population density was decreased,only about 45 ind./mL.3.Effects of combination of temperature and proanthocyanidins on aging and population of B.calyciflorusThe results of the experiment showed that the two exogenous factors had significant effects on the life span,reproduction and population changes of B.calyciflorus by the Two-Way ANOVA.In 25?,the effects of proanthocyanidins on B.calyciflorus was basically consistent with the previous experimental results.In 20?,low concentration proanthocyanidins had no significant effect on lifespan of rotifers.Instead,high concentration proanthocyanidins inhibited their lifespan.The effects of proanthocyanidins on the pregenital period,reproductive capacity and population change of rotifer had no significant difference.In 30?,proanthocyanidin has a better protective effect on rotifers,the average lifespan of rotifer in the control group was 156±6.87h,0.8?g/mL treatment group was significantly prolonged rotifers'lifespan(P<0.05)to 200.5±7.37h;proanthocyanidins can delay the reproductive peak of rotifer at least 12h,but had no significant effect on the pregenital period and reproductive capacity;the control group holds a maximum of about 40 per milliliter of rotifers,each concentration of procyanidins can expand the rotifer environmental capacity,with 0.4?g/mL is the best,can accommodate about 65 rotifers,about 40%higher than the control group.4.Effects on the aging of offsprings of B.calyciflorus which have treated dy PC and temperatureWe treated the B.calyciflorus with different concentrations of proanthocyanidins and different temperatures,then observed the effects of their offsprings' lifespan and reproduction.The results showed that,the average lifespan of B.calyciflorus in the control group without treated with proanthocyanidins was 167±4.44h,the average lifespan of 0.2,0.4,0.8 and 1.0?g/mL treatment groups were 164±8.23.175.5±6.54?160.5±7.40 and 169.514.82h,no significant difference with the control group(P>0.05);pregenital period and reproductive capacity of offsprings also had no obvious change.Stimulated B.calyciflorus with 20? and 30? respectively,average life span,pregenital period and reproductive capacity of their offspring had no obvious change.The experiment showed that the two exogenous factors,proanthocyanidins and temperature,had no effect on the transgenerational plasticity of B.calyciflorus.