Pest rodents pose a serious threat to island biodiversity.Fertility control could be an alternative approach to control the impact of rodents on these islands.In this study,we examined the antifertility effects of EP-...Pest rodents pose a serious threat to island biodiversity.Fertility control could be an alternative approach to control the impact of rodents on these islands.In this study,we examined the antifertility effects of EP-1 baits containing quinestrol(E)and levonorgestrel(P)using a dose of 50 ppm E and P at three different ratios(E:P ratio=1:2,1:1,and 2:1)on Pacific rats(Rattus exulans)in the Xisha Islands,Hainan,China.Compared to the control group,all animals in EP-1 treatment groups showed significantly decreased food intake and body weight.In treated males,there were obvious abnormalities in testis structure and a significant decrease of relative seminal vesicle weight,but no significant effect on relative uterine and ovarian weights(g kg-1 body weight),or ovarian structure in females.Adding 8%sucrose to the original 50-ppm baits(E:P ratio=1:1)significantly increased bait palatability for males and females.This dose induced uterine edema and abnormalities of ovarian structure in females but had no significant negative effect on the relative testis,epididymis,and seminal vesicle weights(g kg-1 body weight)or sperm density in males.In summary,50-ppm EP-1(1:1)baits have the potential to disrupt the fertility of females,and 8%sucrose addition to the EP-1 baits(E:P ratio=1:1)could improve bait palatability.This dose disrupted the testis structure in males.Future studies are needed to improve bait acceptance and assess the antifertility effects of EP-1(1:1)on Pacific rats in captive breeding trials and underfield conditions.展开更多
Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands o...Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia,China.In 2009,we studied the contraceptive effect of levonorgestrel-quinestrol(EP-1),concentration 50 ppm,on a wild Mongolian gerbil population.The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia.The results show that juveniles were not recruited in spring in the treatment group.Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer(one-way ANOVA,F_(2,14)=7.53,P<0.05).Between both groups,annual fluctuations of juvenile and total population densities were significantly different respectively(F_(2,14)=4.64,P<0.05;F_(2,18)=7.72,P<0.05).The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations.This suppressed birth rates of gerbil populations,reduced their densities,and changed their age structures.The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.展开更多
The plateau zokor(Eospalax baileyi)is a key species in the Qinghai-Tibetan Plateau ecosystem,and fertility control could be an ideal approach to manage populations of this subterranean species.In this laboratory study...The plateau zokor(Eospalax baileyi)is a key species in the Qinghai-Tibetan Plateau ecosystem,and fertility control could be an ideal approach to manage populations of this subterranean species.In this laboratory study,we explored the effects of the mixture of levonorgestrel and quinestrol(EP-1,1:2),quinestrol(E),and levonorgestrel(P)on the reproductive status of plateau zokors.Groups of 5 animals of each sex were treated with different concentrations of EP-1(1,5,and 10 mg/kg),E(0.33,3.3,and 6.6 mg/kg),and P(0.67,3.35,and 6.7 mg/kg)by oral gavage over 7 successive days and killed on day 15.Body mass reduction was observed in the EP-1 and E groups.EP-1 and E significantly reduced the weight of testis and epididymis at 10 and 3.3 mg/kg,respectively.Sperm count and motility were significantly reduced by 5 mg/kg EP-1 and 0.33 mg/kg E.The levels of serum testosterone,estradiol,luteinizing hormone,and follicle stimulating hormone were significantly reduced by 5 mg/kg EP-1 and 3.3 mg/kg E.EP-1 and E significantly increased the uterine and ovarian weights at 10 and 3.3 mg/kg,respectively.In the plateau zokors,treatment with P had no influence on the reproductive status.These data demonstrate that EP-1 and E have an inhibitory effect on a range of reproductive parameters in the plateau zokors.Further assessment is required to determine the effects on breeding and recruitment in enclosure orfield experiments.展开更多
The cause of virulence decline of hypovirulent isolate Ep-1PN of Sclerotinia sclerotiorum (Lib.) de Bary has been studied through transmitting test and analysing its offsprings derived from single ascospore. When the ...The cause of virulence decline of hypovirulent isolate Ep-1PN of Sclerotinia sclerotiorum (Lib.) de Bary has been studied through transmitting test and analysing its offsprings derived from single ascospore. When the colony of a normal strain Ep-1PNA 183 intermingled with the colony of Ep-1PN, its margin became abnormal, just like Ep-1PN. Cultures isolated from top-tip of the colony of Ep-1PNA 183 showed the hypovirulence and its associated properties of Ep-1PN. Moreover, a series of cultures which have characteristics between Ep-1PN and normal strain could be isolated from stipes of Ep-1PN. More than 200 offsprings derived from single ascospore of Ep-1PN were normal strains. According to those results, there exists a transmissible cytoplasmic hypovirulent element in hypovirulent isolate Ep-1PN of S. sclerotiorum.展开更多
基金The research was supported by the specific re-search fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202112)The State Key Laboratory of Integrated Management of Pest Insects and Rodents(Grant No.IPM2103)the 2022 PhD Launch Fund to Jing Liu(RC2200002593).
文摘Pest rodents pose a serious threat to island biodiversity.Fertility control could be an alternative approach to control the impact of rodents on these islands.In this study,we examined the antifertility effects of EP-1 baits containing quinestrol(E)and levonorgestrel(P)using a dose of 50 ppm E and P at three different ratios(E:P ratio=1:2,1:1,and 2:1)on Pacific rats(Rattus exulans)in the Xisha Islands,Hainan,China.Compared to the control group,all animals in EP-1 treatment groups showed significantly decreased food intake and body weight.In treated males,there were obvious abnormalities in testis structure and a significant decrease of relative seminal vesicle weight,but no significant effect on relative uterine and ovarian weights(g kg-1 body weight),or ovarian structure in females.Adding 8%sucrose to the original 50-ppm baits(E:P ratio=1:1)significantly increased bait palatability for males and females.This dose induced uterine edema and abnormalities of ovarian structure in females but had no significant negative effect on the relative testis,epididymis,and seminal vesicle weights(g kg-1 body weight)or sperm density in males.In summary,50-ppm EP-1(1:1)baits have the potential to disrupt the fertility of females,and 8%sucrose addition to the EP-1 baits(E:P ratio=1:1)could improve bait palatability.This dose disrupted the testis structure in males.Future studies are needed to improve bait acceptance and assess the antifertility effects of EP-1(1:1)on Pacific rats in captive breeding trials and underfield conditions.
基金supported by National Key Basic Research and Development Program of China(No.2007CB109105).
文摘Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China.The Mongolian gerbil(Meriones unguiculatus)is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia,China.In 2009,we studied the contraceptive effect of levonorgestrel-quinestrol(EP-1),concentration 50 ppm,on a wild Mongolian gerbil population.The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia.The results show that juveniles were not recruited in spring in the treatment group.Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer(one-way ANOVA,F_(2,14)=7.53,P<0.05).Between both groups,annual fluctuations of juvenile and total population densities were significantly different respectively(F_(2,14)=4.64,P<0.05;F_(2,18)=7.72,P<0.05).The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations.This suppressed birth rates of gerbil populations,reduced their densities,and changed their age structures.The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.
基金supported by the Program for Longyuan Youth Innovation Talents of Gansu Province of China(LQ20180918-2)the Technology Support Program of Gansu Forestry and Grassland Administration(LCJ20210020)the International Partnership Program of Chinese Academy of Sciences(152111KYSB20160089).
文摘The plateau zokor(Eospalax baileyi)is a key species in the Qinghai-Tibetan Plateau ecosystem,and fertility control could be an ideal approach to manage populations of this subterranean species.In this laboratory study,we explored the effects of the mixture of levonorgestrel and quinestrol(EP-1,1:2),quinestrol(E),and levonorgestrel(P)on the reproductive status of plateau zokors.Groups of 5 animals of each sex were treated with different concentrations of EP-1(1,5,and 10 mg/kg),E(0.33,3.3,and 6.6 mg/kg),and P(0.67,3.35,and 6.7 mg/kg)by oral gavage over 7 successive days and killed on day 15.Body mass reduction was observed in the EP-1 and E groups.EP-1 and E significantly reduced the weight of testis and epididymis at 10 and 3.3 mg/kg,respectively.Sperm count and motility were significantly reduced by 5 mg/kg EP-1 and 0.33 mg/kg E.The levels of serum testosterone,estradiol,luteinizing hormone,and follicle stimulating hormone were significantly reduced by 5 mg/kg EP-1 and 3.3 mg/kg E.EP-1 and E significantly increased the uterine and ovarian weights at 10 and 3.3 mg/kg,respectively.In the plateau zokors,treatment with P had no influence on the reproductive status.These data demonstrate that EP-1 and E have an inhibitory effect on a range of reproductive parameters in the plateau zokors.Further assessment is required to determine the effects on breeding and recruitment in enclosure orfield experiments.
文摘The cause of virulence decline of hypovirulent isolate Ep-1PN of Sclerotinia sclerotiorum (Lib.) de Bary has been studied through transmitting test and analysing its offsprings derived from single ascospore. When the colony of a normal strain Ep-1PNA 183 intermingled with the colony of Ep-1PN, its margin became abnormal, just like Ep-1PN. Cultures isolated from top-tip of the colony of Ep-1PNA 183 showed the hypovirulence and its associated properties of Ep-1PN. Moreover, a series of cultures which have characteristics between Ep-1PN and normal strain could be isolated from stipes of Ep-1PN. More than 200 offsprings derived from single ascospore of Ep-1PN were normal strains. According to those results, there exists a transmissible cytoplasmic hypovirulent element in hypovirulent isolate Ep-1PN of S. sclerotiorum.
