奶牛能量负平衡(negative energy balance,NEB)是奶牛产后泌乳初期常会发生的一种代谢性疾病,当奶牛摄入能量无法满足其消耗能量时就会达到NEB状态。奶牛处于NEB状态时易引起患病率增加、妊娠率降低、生产性能下降,给集约化奶牛生产带...奶牛能量负平衡(negative energy balance,NEB)是奶牛产后泌乳初期常会发生的一种代谢性疾病,当奶牛摄入能量无法满足其消耗能量时就会达到NEB状态。奶牛处于NEB状态时易引起患病率增加、妊娠率降低、生产性能下降,给集约化奶牛生产带来很大的经济损失。随着分子、组学技术的广泛应用,奶牛泌乳初期NEB对牛卵泡发育的影响机制得到进一步揭示。本文根据近年来相关报道,综述奶牛早期泌乳NEB对牛卵泡发育分子机制相关研究进展并进行展望,以期为减少NEB对奶牛繁殖性能的不利影响提供理论参考。展开更多
The oriental armyworm,Mythimna separata,is a major long-distance migratory insect pest of grain crops in China and other Asian countries.Migratory flights and reproductive behavior usually occur at night,regulated by ...The oriental armyworm,Mythimna separata,is a major long-distance migratory insect pest of grain crops in China and other Asian countries.Migratory flights and reproductive behavior usually occur at night,regulated by a circadian rhythm.However,knowledge about the linkages between adult flight,reproduction,and clock genes is still incomplete.To fill this important gap in our knowledge,a clock gene(designated Msper)was identified and phylogenetic analysis indicated that the encoded protein(MsPER)was highly similar to PER proteins from other insect species.Quantitative RT-PCR assays demonstrated that significantly different spatiotemporal and circadian rhythmic accumulations of mRNA encoding MsPER occurred during development under steady 14 h:10 h light:dark conditions.The highest mRNA accumulation occurred in adult antennae and the lowest in larvae.Msper was expressed rhythmically in adult antennae,relatively less in photophase and more entering scotophase.Injecting small interference RNA(siRNA)into adult heads effectively knocked down Msper mRNA levels within 72 h.Most siRNA-injected adults reduced their evening flight activity significantly and did not exhibit a normal evening peak of flight activity.They also failed to mate and lay eggs within 72 h.Adult mating behavior was restored to control levels by 72 h post injection.We infer that Msper is a prominent clock gene that acts in regulating adult migratory flight and mating behaviors of M.separata.Because of its influence on migration and mating,Msper may be a valuable gene to target for effective management of this migratory insect.展开更多
A kind of stochastic susceptible-exposed but not infectiousinfectious-removed (SEIR) model with constant immigration in incubation period is presented, based on a deterministic SEIR model, via the technique of paramet...A kind of stochastic susceptible-exposed but not infectiousinfectious-removed (SEIR) model with constant immigration in incubation period is presented, based on a deterministic SEIR model, via the technique of parameter perturbation which is standard in stochastic population modeling. The influence of the environmental noise as a standard Gaussian white noise on the epidemics' transmission is studied. Furthermore,the condition for the epidemics' persistence is obtained by formulating the corresponding function and using It 's formula. And the asymptotic behavior of the model near the endemic disease equilibrium is also studied. In this way, the decision support is provided in the application of this kind of stochastic SEIR model on the epidemics' prevention and control.展开更多
?College of Life Science, Hebei Normal University, Shijiazhuang 050016, China)Golden pheasant ( Chrysolophus pictus) is a monotypic and special species of China.In nature, it breeds once a year in spring summer.From O...?College of Life Science, Hebei Normal University, Shijiazhuang 050016, China)Golden pheasant ( Chrysolophus pictus) is a monotypic and special species of China.In nature, it breeds once a year in spring summer.From Oct.1998 to Feb.1999, we studied the effects of photo periods on inducing the birds to reproduce in winter and succeeded.In the experiment, 36 adult females and 18 males were divided into three groups.Each group was divided into 6 replicates, each replicate included 2 females and 1 male, and fed in one cage.All the groups were exposed to short day (8L∶16D) for 8 weeks, and then transferred to long day (12L∶12D, 14L∶10D or 16L∶8D). In result, photoperiods significantly affected Golden pheasant reproductive performance in winter.Considered of all of the reproductive performance indicators, the reproductive performance of the group exposure to 14L∶10D was the best, the 16L∶8D group’s was less and the 12L∶12D group’s was the worst.It may be that the birds’ CDL (critical day length) for inducing egg production was about 12 h, and the CDL for optimal egg production was 14L∶10D in winter. The birds exposed to 12L∶12D had no fertilized egg.The other groups had fertilized eggs and the fertility was 15 05% (14L∶10D) and 20 41% (16L∶8D).The hatchability of fertilized egg were 76 47% (14L∶10D) and 80 00% (16L∶8D). The egg laying pattern was affected by the size of photoperiod.The ratio of lay of the birds exposed to 14L∶10D, increased rapidly and sustained in a peak level for 5 weeks, and then fall down.But the other birds (group A and C) increased to the peak at the first week and then fall down quickly.展开更多
文摘奶牛能量负平衡(negative energy balance,NEB)是奶牛产后泌乳初期常会发生的一种代谢性疾病,当奶牛摄入能量无法满足其消耗能量时就会达到NEB状态。奶牛处于NEB状态时易引起患病率增加、妊娠率降低、生产性能下降,给集约化奶牛生产带来很大的经济损失。随着分子、组学技术的广泛应用,奶牛泌乳初期NEB对牛卵泡发育的影响机制得到进一步揭示。本文根据近年来相关报道,综述奶牛早期泌乳NEB对牛卵泡发育分子机制相关研究进展并进行展望,以期为减少NEB对奶牛繁殖性能的不利影响提供理论参考。
基金the National Natural Science Foundation of China(No.32072420,31871951,31672019)China Agriculture Research System of MOF and MARA(CARS-22)the National Key Research and Development Program of China(2017YFD0201802,2017YFD0201701).
文摘The oriental armyworm,Mythimna separata,is a major long-distance migratory insect pest of grain crops in China and other Asian countries.Migratory flights and reproductive behavior usually occur at night,regulated by a circadian rhythm.However,knowledge about the linkages between adult flight,reproduction,and clock genes is still incomplete.To fill this important gap in our knowledge,a clock gene(designated Msper)was identified and phylogenetic analysis indicated that the encoded protein(MsPER)was highly similar to PER proteins from other insect species.Quantitative RT-PCR assays demonstrated that significantly different spatiotemporal and circadian rhythmic accumulations of mRNA encoding MsPER occurred during development under steady 14 h:10 h light:dark conditions.The highest mRNA accumulation occurred in adult antennae and the lowest in larvae.Msper was expressed rhythmically in adult antennae,relatively less in photophase and more entering scotophase.Injecting small interference RNA(siRNA)into adult heads effectively knocked down Msper mRNA levels within 72 h.Most siRNA-injected adults reduced their evening flight activity significantly and did not exhibit a normal evening peak of flight activity.They also failed to mate and lay eggs within 72 h.Adult mating behavior was restored to control levels by 72 h post injection.We infer that Msper is a prominent clock gene that acts in regulating adult migratory flight and mating behaviors of M.separata.Because of its influence on migration and mating,Msper may be a valuable gene to target for effective management of this migratory insect.
基金Humanities and Social Science Research Planning Fund of the Education Ministry of China(No.15YJCZH2010)the Research Innovation Program of Shanghai Municipal Education Commission,China(No.14YZ134)Shanghai 085 Project for Municipal Universities,China
文摘A kind of stochastic susceptible-exposed but not infectiousinfectious-removed (SEIR) model with constant immigration in incubation period is presented, based on a deterministic SEIR model, via the technique of parameter perturbation which is standard in stochastic population modeling. The influence of the environmental noise as a standard Gaussian white noise on the epidemics' transmission is studied. Furthermore,the condition for the epidemics' persistence is obtained by formulating the corresponding function and using It 's formula. And the asymptotic behavior of the model near the endemic disease equilibrium is also studied. In this way, the decision support is provided in the application of this kind of stochastic SEIR model on the epidemics' prevention and control.
文摘?College of Life Science, Hebei Normal University, Shijiazhuang 050016, China)Golden pheasant ( Chrysolophus pictus) is a monotypic and special species of China.In nature, it breeds once a year in spring summer.From Oct.1998 to Feb.1999, we studied the effects of photo periods on inducing the birds to reproduce in winter and succeeded.In the experiment, 36 adult females and 18 males were divided into three groups.Each group was divided into 6 replicates, each replicate included 2 females and 1 male, and fed in one cage.All the groups were exposed to short day (8L∶16D) for 8 weeks, and then transferred to long day (12L∶12D, 14L∶10D or 16L∶8D). In result, photoperiods significantly affected Golden pheasant reproductive performance in winter.Considered of all of the reproductive performance indicators, the reproductive performance of the group exposure to 14L∶10D was the best, the 16L∶8D group’s was less and the 12L∶12D group’s was the worst.It may be that the birds’ CDL (critical day length) for inducing egg production was about 12 h, and the CDL for optimal egg production was 14L∶10D in winter. The birds exposed to 12L∶12D had no fertilized egg.The other groups had fertilized eggs and the fertility was 15 05% (14L∶10D) and 20 41% (16L∶8D).The hatchability of fertilized egg were 76 47% (14L∶10D) and 80 00% (16L∶8D). The egg laying pattern was affected by the size of photoperiod.The ratio of lay of the birds exposed to 14L∶10D, increased rapidly and sustained in a peak level for 5 weeks, and then fall down.But the other birds (group A and C) increased to the peak at the first week and then fall down quickly.
