Ambient temperature is an importa nt factor in flue ncing many physiological processes, in eluding antioxidant defense and immunity. In the present study, we tested the hypothesis that antioxidant defense and immunity...Ambient temperature is an importa nt factor in flue ncing many physiological processes, in eluding antioxidant defense and immunity. In the present study, we tested the hypothesis that antioxidant defense and immunity are suppressed by high and low temperature treatme nt in Bran dt's voles (Lasiopodomys brandtii). Thirty male voles were randomly assigned into different temperature groups (4, 23, and 32℃, n=10 for each group), with the treatment course lasting for 27 d. Results showed that low temperature in creased gross en ergy in take (GEI) and liver, heart, and kidney mass, but decreased body fat mass and dry carcass mass. With the decline in temperature, hydrogen peroxide (H2O2) concentration, which is indicative of reactive oxyge n species (ROS) levels, in creased in the liver, decreased in the heart, and was unchanged in the kidney, testis, and small intestine. Lipid peroxidation indicated by malonaldehyde (MDA) content in the liver, heart, kidney, testis, and small intestine did not differ among groups, implying that high and low temperature did not cause oxidative damage. Similarly, superoxide dismutase (SOD) and catalase (CAT) activities and total antioxidant capacity (TAOC) in the five tissues did not respond to low or high temperature, except for elevation of CAT activity in the testis upon cold exposure. Bacteria killing capacity, which is indicative of innate immunity, was nearly suppressed in the 4℃ group in contrast to the 23℃ group, whereas spleen mass and white blood cells were un affected by temperature treatment. The levels of testosterone, but not corticostero ne, were in flue need by temperature treatment, though neither were correlated with innate immunity, H2O2 and MDA levels, or SOD, CAT, and TAOC activity in any detected tissues. Overall, these results showed that temperature had different in flue nces on oxidative stress, an tioxida nt en zymes, and immunity, which depended on the tissues and parameters tested. Up-regulation or maintenance of an tioxida nt defe nse might be an importa nt mechanism for voles to survive highly variable environmental temperatures.展开更多
The combination of levonorgestrel and quinestrol(EP-1)has been shown to have anti-fertility effects on several wild rodents,but the mechanism underlying these effects is poorly understood.We investigated the effects o...The combination of levonorgestrel and quinestrol(EP-1)has been shown to have anti-fertility effects on several wild rodents,but the mechanism underlying these effects is poorly understood.We investigated the effects of EP-1 and each of its components,levonorgestrel(P)and quinestrol(E),on the fertility of Brandt’s voles(Lasiopodomys brandtii)by using a gastric gavage method.The doses for EP-1,E and P were 1,0.34 and 0.66 mg/kg body weight,respectively.Male voles(n=98)were treated daily for 5 or 14 days,then the testes and epididymides were collected,weighed and examined histologically at 30(D30),60(D60)or 90(D90)days after the end of treatment.Four males were allowed to mate with normal females at D90.Female voles(n=75)were treated for 3 days and a further 3 days after a 7-day interval.The uteri and ovaries were weighed and examined histologically at 15(D15),30(D30)or 75(D75)days after the end of treatment.Each of three females were mated with fertile males at D30 and D75,respectively.Our results indicated that quinestrol(E)significantly decreased the sperm numbers in the testes as well as the weight of the testes and epididymides,with both of these tissues showing obvious structural abnormalities,and significantly reduced the litter size and the pup weight for females mated with males of the E treatment group.For female voles,treatment with E,P or EP-1 resulted in no marked influence on the fertility status.These data indicate that quinestrol(E)alone has a significant anti-fertility effect on male Brandt’s voles,but is ineffective in combination with levonorgestrel(P).展开更多
Age structure and seasonality influence the population fluctuations of small rodents.Age determines body weight and social experience,while seasonality regulates the duration of the breeding season and onset of sex...Age structure and seasonality influence the population fluctuations of small rodents.Age determines body weight and social experience,while seasonality regulates the duration of the breeding season and onset of sexual maturity in newborn offspring.Therefore,reproductive success and skew usually occur in different age groups.Brandt’s vole(Lasiopodomys brandtii)is a social,short-lived and seasonal breeding small rodent with a dramatic seasonal population fluctuation,but reproductive skew is not fully understood in this species.In the present study,we determined kinship in semi-natural enclosure populations using microsatellite markers based on genotyping,analyzed the reproductive skew between sexes and between overwintered and newborn voles,and monitored variation in male reproductive activity by testing fecal testosterone levels throughout the year.Overwintered voles had the most reproductive success along with a striking increase in the population size in the enclosures,with all biological fathers and 77.8%of biological mothers,which had 100%and 87%of the total offspring,respectively.Compared to overwintered voles,reproductive skews were significantly higher in potential overwintered and newborn parents,implying the possible reproductive suppression of newborn voles by dominant overwintered voles.Moreover,both heavier body weight and higher testosterone levels in overwintered males supported their potential social status in the population.Our study provided new evidence for reproductive skew and differentiation of postnatal gonadal development patterns of different age groups in Brandt’s vole.展开更多
Maternal effects play a crucial role in regulating populations of small mammals and anti-predator behaviors of offspring.The present study investigated the effects of maternal stress induced by exposure to predator od...Maternal effects play a crucial role in regulating populations of small mammals and anti-predator behaviors of offspring.The present study investigated the effects of maternal stress induced by exposure to predator odors during gestation on the behavioral and physiological responses of offspring in Brandt’s vole(Lasiopodomys brandtii).Effects included changes in growth,behaviors,hormone levels in serum,and fosB/ΔfosB mRNA and FosB/ΔFosB protein expression in the hypothalamus.Our results showed that when pregnant voles were exposed to cat and rabbit urine odors for 18 days(1 h/day),the weight of the female offspring decreased;however,the thymus and ovary indices increased,compared with the control group.Male offspring of voles exposed to cat odor spent more time exploring and foraging,and showed a decrease in corticosterone(CORT)compared with voles in the control group.Both fosB/ΔfosB mRNA and FosB/ΔFosB protein expressions were downregulated in the hypothalamus of male offspring in the cat odor-exposed group compared to that in offspring in the control group.However,the mRNA levels of fosB/ΔfosB in the hypothalamus of female offspring did not decrease in response to cat urine odor.Our findings suggested that maternal stress induced by predator odors during gestation restrained the growth of female offspring and increased the duration of exploring and foraging behaviors of male offspring by regulating the HPA axis,which,in turn,reduced the sensitivity of offspring to unfamiliar environments and increased their probability of becoming prey.展开更多
We studied the infectious effect of SARS-CoV virus on juvenile and adult Brandt’s Vole (Microtus brandtii) by nasal cavity spraying method (CCID50 is 105.7). SARS virus caused serious deaths in adults. The death adul...We studied the infectious effect of SARS-CoV virus on juvenile and adult Brandt’s Vole (Microtus brandtii) by nasal cavity spraying method (CCID50 is 105.7). SARS virus caused serious deaths in adults. The death adults demonstrated hemorrhage from mouth, nasal cavity and intestine, hemorrhageious interstitial pneumonia and gore in liver, spleen and kidney. The survival adults demonstrated local hemorrhagic spot in lung and emphysema, but the other organs showed no pathological abnormality. SARS virus caused no deaths in juveniles, but locomotion of infected juveniles became slower. In the early stage, there was local pneumonia in lung and SARS viruses were isolated from the pathological tissue. Only one control juvenile lived and the infected juvenile showed local pneumonia in lung. The results demonstrated that SARS-CoV infected Brandt’s vole seriously and adults were more susceptive to SARS-CoV than juveniles. The Brandt’s vole may be a potential animal model for SARS research.展开更多
基金supported by the National Natural Science Foundation of China(31770444)the State Key Laboratory of Integrated Management of Pest Insects and Rodents(IPM1906)
文摘Ambient temperature is an importa nt factor in flue ncing many physiological processes, in eluding antioxidant defense and immunity. In the present study, we tested the hypothesis that antioxidant defense and immunity are suppressed by high and low temperature treatme nt in Bran dt's voles (Lasiopodomys brandtii). Thirty male voles were randomly assigned into different temperature groups (4, 23, and 32℃, n=10 for each group), with the treatment course lasting for 27 d. Results showed that low temperature in creased gross en ergy in take (GEI) and liver, heart, and kidney mass, but decreased body fat mass and dry carcass mass. With the decline in temperature, hydrogen peroxide (H2O2) concentration, which is indicative of reactive oxyge n species (ROS) levels, in creased in the liver, decreased in the heart, and was unchanged in the kidney, testis, and small intestine. Lipid peroxidation indicated by malonaldehyde (MDA) content in the liver, heart, kidney, testis, and small intestine did not differ among groups, implying that high and low temperature did not cause oxidative damage. Similarly, superoxide dismutase (SOD) and catalase (CAT) activities and total antioxidant capacity (TAOC) in the five tissues did not respond to low or high temperature, except for elevation of CAT activity in the testis upon cold exposure. Bacteria killing capacity, which is indicative of innate immunity, was nearly suppressed in the 4℃ group in contrast to the 23℃ group, whereas spleen mass and white blood cells were un affected by temperature treatment. The levels of testosterone, but not corticostero ne, were in flue need by temperature treatment, though neither were correlated with innate immunity, H2O2 and MDA levels, or SOD, CAT, and TAOC activity in any detected tissues. Overall, these results showed that temperature had different in flue nces on oxidative stress, an tioxida nt en zymes, and immunity, which depended on the tissues and parameters tested. Up-regulation or maintenance of an tioxida nt defe nse might be an importa nt mechanism for voles to survive highly variable environmental temperatures.
基金the Key Project of the Ministry of Science and Technology(2005BA529A05)the Chinese Academy of Sciences Innovative Research International Partnership Project(CXTDS2005-4)the Australian Centre for International Agricultural Research(AS1/2002/108).
文摘The combination of levonorgestrel and quinestrol(EP-1)has been shown to have anti-fertility effects on several wild rodents,but the mechanism underlying these effects is poorly understood.We investigated the effects of EP-1 and each of its components,levonorgestrel(P)and quinestrol(E),on the fertility of Brandt’s voles(Lasiopodomys brandtii)by using a gastric gavage method.The doses for EP-1,E and P were 1,0.34 and 0.66 mg/kg body weight,respectively.Male voles(n=98)were treated daily for 5 or 14 days,then the testes and epididymides were collected,weighed and examined histologically at 30(D30),60(D60)or 90(D90)days after the end of treatment.Four males were allowed to mate with normal females at D90.Female voles(n=75)were treated for 3 days and a further 3 days after a 7-day interval.The uteri and ovaries were weighed and examined histologically at 15(D15),30(D30)or 75(D75)days after the end of treatment.Each of three females were mated with fertile males at D30 and D75,respectively.Our results indicated that quinestrol(E)significantly decreased the sperm numbers in the testes as well as the weight of the testes and epididymides,with both of these tissues showing obvious structural abnormalities,and significantly reduced the litter size and the pup weight for females mated with males of the E treatment group.For female voles,treatment with E,P or EP-1 resulted in no marked influence on the fertility status.These data indicate that quinestrol(E)alone has a significant anti-fertility effect on male Brandt’s voles,but is ineffective in combination with levonorgestrel(P).
基金the National Nature Science Foundation of China(31471790)the Agricultural Agricultural Science and Technology Innovation Program(National Key Technology R&D Program,2012BAD19B02)the National Basic Research Program of China(973 Program,2007CB109104)。
文摘Age structure and seasonality influence the population fluctuations of small rodents.Age determines body weight and social experience,while seasonality regulates the duration of the breeding season and onset of sexual maturity in newborn offspring.Therefore,reproductive success and skew usually occur in different age groups.Brandt’s vole(Lasiopodomys brandtii)is a social,short-lived and seasonal breeding small rodent with a dramatic seasonal population fluctuation,but reproductive skew is not fully understood in this species.In the present study,we determined kinship in semi-natural enclosure populations using microsatellite markers based on genotyping,analyzed the reproductive skew between sexes and between overwintered and newborn voles,and monitored variation in male reproductive activity by testing fecal testosterone levels throughout the year.Overwintered voles had the most reproductive success along with a striking increase in the population size in the enclosures,with all biological fathers and 77.8%of biological mothers,which had 100%and 87%of the total offspring,respectively.Compared to overwintered voles,reproductive skews were significantly higher in potential overwintered and newborn parents,implying the possible reproductive suppression of newborn voles by dominant overwintered voles.Moreover,both heavier body weight and higher testosterone levels in overwintered males supported their potential social status in the population.Our study provided new evidence for reproductive skew and differentiation of postnatal gonadal development patterns of different age groups in Brandt’s vole.
基金This work was supported by the National Natural Science Foundation of China(No.31770422 and No.31370415)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Maternal effects play a crucial role in regulating populations of small mammals and anti-predator behaviors of offspring.The present study investigated the effects of maternal stress induced by exposure to predator odors during gestation on the behavioral and physiological responses of offspring in Brandt’s vole(Lasiopodomys brandtii).Effects included changes in growth,behaviors,hormone levels in serum,and fosB/ΔfosB mRNA and FosB/ΔFosB protein expression in the hypothalamus.Our results showed that when pregnant voles were exposed to cat and rabbit urine odors for 18 days(1 h/day),the weight of the female offspring decreased;however,the thymus and ovary indices increased,compared with the control group.Male offspring of voles exposed to cat odor spent more time exploring and foraging,and showed a decrease in corticosterone(CORT)compared with voles in the control group.Both fosB/ΔfosB mRNA and FosB/ΔFosB protein expressions were downregulated in the hypothalamus of male offspring in the cat odor-exposed group compared to that in offspring in the control group.However,the mRNA levels of fosB/ΔfosB in the hypothalamus of female offspring did not decrease in response to cat urine odor.Our findings suggested that maternal stress induced by predator odors during gestation restrained the growth of female offspring and increased the duration of exploring and foraging behaviors of male offspring by regulating the HPA axis,which,in turn,reduced the sensitivity of offspring to unfamiliar environments and increased their probability of becoming prey.
基金supported by the Innovation Program of Institute of Zoology,the Chinese Academy of Sciences
文摘We studied the infectious effect of SARS-CoV virus on juvenile and adult Brandt’s Vole (Microtus brandtii) by nasal cavity spraying method (CCID50 is 105.7). SARS virus caused serious deaths in adults. The death adults demonstrated hemorrhage from mouth, nasal cavity and intestine, hemorrhageious interstitial pneumonia and gore in liver, spleen and kidney. The survival adults demonstrated local hemorrhagic spot in lung and emphysema, but the other organs showed no pathological abnormality. SARS virus caused no deaths in juveniles, but locomotion of infected juveniles became slower. In the early stage, there was local pneumonia in lung and SARS viruses were isolated from the pathological tissue. Only one control juvenile lived and the infected juvenile showed local pneumonia in lung. The results demonstrated that SARS-CoV infected Brandt’s vole seriously and adults were more susceptive to SARS-CoV than juveniles. The Brandt’s vole may be a potential animal model for SARS research.
