家禽是长日照动物,科学合理的光照程序对蛋鸡的生长发育、性成熟、开产日龄、产蛋高峰等都有显著影响,在诱导换羽的禁食和恢复采食的不同阶段,设定相应的光照程序对于提升诱导换羽效果具有重要的意义。该研究选用529日龄体重相近、产蛋...家禽是长日照动物,科学合理的光照程序对蛋鸡的生长发育、性成熟、开产日龄、产蛋高峰等都有显著影响,在诱导换羽的禁食和恢复采食的不同阶段,设定相应的光照程序对于提升诱导换羽效果具有重要的意义。该研究选用529日龄体重相近、产蛋率约为60%的贵妃蛋鸡为试验材料,根据禁食诱导换羽的不同时期,将光照制度的变化分4个阶段,并于第Ⅰ阶段(16 h L/8 h D,禁食前)、第Ⅱ阶段(8 h L/16 h D持续3 d)、第Ⅲ阶段(10 h L/14 h D持续13 d)的最后1天(F 0、F 3、F 16)和第Ⅳ阶段(逐渐增加光照0.5 h/d至恢复到16 h L/8 h D)的第6、32天(R 6、R 32)5个不同时期屠宰采样,通过卵泡数量、卵巢抗氧化指标、KIT-PI3K-PTEN-AKT信号通路和GDF9基因表达量等来探究光照程序在禁食诱导换羽过程的作用。结果表明,缩短光照蛋鸡血清中生殖激素FSH、LH、E 2和P 4的水平降低(P<0.001),超氧化物歧化酶(P<0.05)、谷胱甘肽过氧化酶(P<0.001)活力增强,在此过程中原始卵泡可能被激活,使小黄卵泡(P<0.01)、大白卵泡(P>0.05)的数量增多;逐渐恢复光照时长过程中KIT和PI3K处于持续高表达状态(P<0.001),PTEN相对表达量降低(P<0.01),而AKT相对表达量基本不变(P>0.05),且血清中生殖激素水平和卵巢抗氧化水平恢复到初始状态,但整体卵泡数量有所上升。该结果表明在禁食换羽过程中科学合理的光照程序对卵巢功能的重塑具有辅助作用。展开更多
This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone （20-HE） concentration for juvenile Fenneropenaeus chinensis with an...This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone （20-HE） concentration for juvenile Fenneropenaeus chinensis with an initial wet body weight of 1.115 g±0.012 g. The salinity of the control treatment （represented by DO） was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The range of salinity fluctuation was 4. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8d, respectively; each original salinity was decreased abruptly to salinity 24, which first lasted for another 2 d and was then raised to its initial value 28. This constituted a salinity fluctuation cycle and afterwards the cycle repeated. It was found that： 1） The weight gain of shrimp in treatment D4 was 202.9% and significantly higher than that in treatment DO （P〈0.05）. The molting rate in treatment D2 was the lowest, while that in treatment D6 was the highest and significantly higher than those in treatments DO and D2 （P〈0.05）. 2） The hemolymph 20-HE concentration of shrimps in all treatments was at low levels and increased first gradually during the inter-molt period and then increased sharply. It reached a peak value during the pre-molt stage, and then decreased abruptly during the post-molt stage when the lowest level occurred. 3） During the post-molt stage, the hemolymph 20-HE concentration in treatment D2 was 7.47pg μL^-1 and significantly higher than that in treatment DO （P〈0.05）. There were, however, no significant differences in hemolymph 20-HE concentration among all five treatments during the inter-molt stage （P〉0.05）. During the pre-molt stage, the hemolymph 20-HE concentration in treatment D6 was significantly higher than that in treatment DO （P〈0.05）, whereas the hemolymph 20-HE concentration in treatment D2 was significantly lower than that in other treatmen展开更多
研究了洋山航道工程疏浚泥悬浮液和浸出液对三疣梭子蟹(Portunus trituberculatus)大眼幼体的毒害效应,结果表明:(1)大眼幼体死亡率随着悬浮液和浸出液配比浓度的增大而逐渐增加。浸出液对大眼幼体的96 h半致死配比浓度φ(LC50)为1 294....研究了洋山航道工程疏浚泥悬浮液和浸出液对三疣梭子蟹(Portunus trituberculatus)大眼幼体的毒害效应,结果表明:(1)大眼幼体死亡率随着悬浮液和浸出液配比浓度的增大而逐渐增加。浸出液对大眼幼体的96 h半致死配比浓度φ(LC50)为1 294.66 m L·L-1,安全配比浓度φ(SC)为129.466 m L·L-1;悬浮液对大眼幼体的96hφ(LC50)为996.17 m L·L-1,φ(SC)为99.617 m L·L-1。(2)大眼幼体的蜕皮率随着悬浮液和浸出液配比浓度的增加而逐渐降低。同体积配比浓度下,浸出液处理组蜕皮率略高于悬浮液处理组。悬浮液抑制三疣梭子蟹大眼幼体的蜕壳,而浸出液抑制新壳的硬化。(3)浸出液和悬浮液胁迫24 h后,大眼幼体肌肉中HSP70表达量迅速升高,浸出液和悬浮液最高配比浓度组表达量显著高于对照组(P<0.05);72 h各处理组HSP70表达量均达到最高值;96 h后各处理组表达量有所降低,最高配比浓度组HSP70表达量降幅明显(P<0.05),对照组表达量仍继续上升。展开更多
文摘家禽是长日照动物,科学合理的光照程序对蛋鸡的生长发育、性成熟、开产日龄、产蛋高峰等都有显著影响,在诱导换羽的禁食和恢复采食的不同阶段,设定相应的光照程序对于提升诱导换羽效果具有重要的意义。该研究选用529日龄体重相近、产蛋率约为60%的贵妃蛋鸡为试验材料,根据禁食诱导换羽的不同时期,将光照制度的变化分4个阶段,并于第Ⅰ阶段(16 h L/8 h D,禁食前)、第Ⅱ阶段(8 h L/16 h D持续3 d)、第Ⅲ阶段(10 h L/14 h D持续13 d)的最后1天(F 0、F 3、F 16)和第Ⅳ阶段(逐渐增加光照0.5 h/d至恢复到16 h L/8 h D)的第6、32天(R 6、R 32)5个不同时期屠宰采样,通过卵泡数量、卵巢抗氧化指标、KIT-PI3K-PTEN-AKT信号通路和GDF9基因表达量等来探究光照程序在禁食诱导换羽过程的作用。结果表明,缩短光照蛋鸡血清中生殖激素FSH、LH、E 2和P 4的水平降低(P<0.001),超氧化物歧化酶(P<0.05)、谷胱甘肽过氧化酶(P<0.001)活力增强,在此过程中原始卵泡可能被激活,使小黄卵泡(P<0.01)、大白卵泡(P>0.05)的数量增多;逐渐恢复光照时长过程中KIT和PI3K处于持续高表达状态(P<0.001),PTEN相对表达量降低(P<0.01),而AKT相对表达量基本不变(P>0.05),且血清中生殖激素水平和卵巢抗氧化水平恢复到初始状态,但整体卵泡数量有所上升。该结果表明在禁食换羽过程中科学合理的光照程序对卵巢功能的重塑具有辅助作用。
基金supported by funds from the National Natural Science Foundation of China (Grant No. 30571441)the Project of Reward Research Foundation for Talented Young and Middle Aged Scientists of Shandong, China (Grant No. 2006BS07002)the National Great Project of Scientific and Technical Supporting Programs Funded by the Ministry of Science and Technology of China in the 11th Five-Year Plan (Grant No. 2006BAD09A07)
文摘This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone （20-HE） concentration for juvenile Fenneropenaeus chinensis with an initial wet body weight of 1.115 g±0.012 g. The salinity of the control treatment （represented by DO） was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The range of salinity fluctuation was 4. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8d, respectively; each original salinity was decreased abruptly to salinity 24, which first lasted for another 2 d and was then raised to its initial value 28. This constituted a salinity fluctuation cycle and afterwards the cycle repeated. It was found that： 1） The weight gain of shrimp in treatment D4 was 202.9% and significantly higher than that in treatment DO （P〈0.05）. The molting rate in treatment D2 was the lowest, while that in treatment D6 was the highest and significantly higher than those in treatments DO and D2 （P〈0.05）. 2） The hemolymph 20-HE concentration of shrimps in all treatments was at low levels and increased first gradually during the inter-molt period and then increased sharply. It reached a peak value during the pre-molt stage, and then decreased abruptly during the post-molt stage when the lowest level occurred. 3） During the post-molt stage, the hemolymph 20-HE concentration in treatment D2 was 7.47pg μL^-1 and significantly higher than that in treatment DO （P〈0.05）. There were, however, no significant differences in hemolymph 20-HE concentration among all five treatments during the inter-molt stage （P〉0.05）. During the pre-molt stage, the hemolymph 20-HE concentration in treatment D6 was significantly higher than that in treatment DO （P〈0.05）, whereas the hemolymph 20-HE concentration in treatment D2 was significantly lower than that in other treatmen
文摘研究了洋山航道工程疏浚泥悬浮液和浸出液对三疣梭子蟹(Portunus trituberculatus)大眼幼体的毒害效应,结果表明:(1)大眼幼体死亡率随着悬浮液和浸出液配比浓度的增大而逐渐增加。浸出液对大眼幼体的96 h半致死配比浓度φ(LC50)为1 294.66 m L·L-1,安全配比浓度φ(SC)为129.466 m L·L-1;悬浮液对大眼幼体的96hφ(LC50)为996.17 m L·L-1,φ(SC)为99.617 m L·L-1。(2)大眼幼体的蜕皮率随着悬浮液和浸出液配比浓度的增加而逐渐降低。同体积配比浓度下,浸出液处理组蜕皮率略高于悬浮液处理组。悬浮液抑制三疣梭子蟹大眼幼体的蜕壳,而浸出液抑制新壳的硬化。(3)浸出液和悬浮液胁迫24 h后,大眼幼体肌肉中HSP70表达量迅速升高,浸出液和悬浮液最高配比浓度组表达量显著高于对照组(P<0.05);72 h各处理组HSP70表达量均达到最高值;96 h后各处理组表达量有所降低,最高配比浓度组HSP70表达量降幅明显(P<0.05),对照组表达量仍继续上升。
