为了高效制备稀有人参皂苷Gyp17和Gyp75,利用大肠杆菌克隆表达人参皂苷酶Ⅲ型酶,转化低活性人参皂苷Rb1,制备稀有人参皂苷Gyp17和Gyp75。结果表明,将20 g/L的Rb1皂苷在37℃酶反应24 h,4 g Rb1底物制备了3.1 g稀有皂苷Gyp17,其摩尔得率为...为了高效制备稀有人参皂苷Gyp17和Gyp75,利用大肠杆菌克隆表达人参皂苷酶Ⅲ型酶,转化低活性人参皂苷Rb1,制备稀有人参皂苷Gyp17和Gyp75。结果表明,将20 g/L的Rb1皂苷在37℃酶反应24 h,4 g Rb1底物制备了3.1 g稀有皂苷Gyp17,其摩尔得率为90.8%。5 g/L的皂苷Rb1在37℃酶反应60 h,4 g Rb1底物制备了2.1 g Gyp75单体和0.45 g Gyp17单体,其摩尔得率分别为74.2%和13.1%。经HPLC检测,所得到Gyp75和Gyp17皂苷单体纯度均在90%以上。该研究为人参稀有皂苷Gyp17和Gyp75的产业化提供依据。展开更多
Variation in offspring sex ratios is a central topic in animal demography and population dynamics.Most studies have focused on bird species with marked sexual dimorphism and multiple-nestling broods,where the offsprin...Variation in offspring sex ratios is a central topic in animal demography and population dynamics.Most studies have focused on bird species with marked sexual dimorphism and multiple-nestling broods,where the offspring sex ratio is often biased due to different individual or environmental variables.However,biases in offspring sex ratios have been far less investigated in monomorphic and single-egg laying species,and few studies have evaluated long-term and large-scale variations in the sex ratio of nestling vultures.Here,we explore individual and environmental factors potentially affecting the secondary sex ratio of the monomorphic griffon vulture Gyps fulvus.We used information collected at three breeding nuclei from central Spain over a 30-year period(1990–2020)to analyse the effects of nestling age,parental age,breeding phenology,conspecific density,population reproductive parameters,and spatial and temporal variability on nestling sex.Sex ratio did not differ from parity either at the population or the nuclei level.No significant between-year differences were detected,even under highly changing conditions of food availability associated with the mad-cow crisis.We found that tree nesting breeders tend to have more sons than daughters,but as this nesting behavior is rare and we consequently have a small sample size,this issue would require additional examination.Whereas further research is needed to assess the potential effect of breeder identity on nestling sex ratio,this study contributes to understanding the basic ecology and population dynamics of Griffon Vultures,a long-lived species with deferred maturity and low fecundity,whose minor deviations in the offspring sex ratio might imply major changes at the population level.展开更多
文摘为了高效制备稀有人参皂苷Gyp17和Gyp75,利用大肠杆菌克隆表达人参皂苷酶Ⅲ型酶,转化低活性人参皂苷Rb1,制备稀有人参皂苷Gyp17和Gyp75。结果表明,将20 g/L的Rb1皂苷在37℃酶反应24 h,4 g Rb1底物制备了3.1 g稀有皂苷Gyp17,其摩尔得率为90.8%。5 g/L的皂苷Rb1在37℃酶反应60 h,4 g Rb1底物制备了2.1 g Gyp75单体和0.45 g Gyp17单体,其摩尔得率分别为74.2%和13.1%。经HPLC检测,所得到Gyp75和Gyp17皂苷单体纯度均在90%以上。该研究为人参稀有皂苷Gyp17和Gyp75的产业化提供依据。
基金The study was carried out with the permission of the regional government of Castilla y Leon,Direccion General del Medio Natural,Servicio de Espacios Naturales.Research was funded by the Spanish Ministry of Economy,Industry,and Competitiveness through projects CGL2007-61395,CGL2010-15726,CGL2013-42451-PPID2019-109685GB-I00 of the Spanish Ministry of Science and Innovation+1 种基金G.G.L.was supported by a FPU fellowship of the Spanish Ministry of Science,Innovation and Universities(FPU19/06511)A.S.A.was supported by a Ramon y Cajal fellowship of the Spanish Ministry of Science(RYC-2017-22796).
文摘Variation in offspring sex ratios is a central topic in animal demography and population dynamics.Most studies have focused on bird species with marked sexual dimorphism and multiple-nestling broods,where the offspring sex ratio is often biased due to different individual or environmental variables.However,biases in offspring sex ratios have been far less investigated in monomorphic and single-egg laying species,and few studies have evaluated long-term and large-scale variations in the sex ratio of nestling vultures.Here,we explore individual and environmental factors potentially affecting the secondary sex ratio of the monomorphic griffon vulture Gyps fulvus.We used information collected at three breeding nuclei from central Spain over a 30-year period(1990–2020)to analyse the effects of nestling age,parental age,breeding phenology,conspecific density,population reproductive parameters,and spatial and temporal variability on nestling sex.Sex ratio did not differ from parity either at the population or the nuclei level.No significant between-year differences were detected,even under highly changing conditions of food availability associated with the mad-cow crisis.We found that tree nesting breeders tend to have more sons than daughters,but as this nesting behavior is rare and we consequently have a small sample size,this issue would require additional examination.Whereas further research is needed to assess the potential effect of breeder identity on nestling sex ratio,this study contributes to understanding the basic ecology and population dynamics of Griffon Vultures,a long-lived species with deferred maturity and low fecundity,whose minor deviations in the offspring sex ratio might imply major changes at the population level.
