Inorganic lead （Pb） is one of the most common environmental pollutants. Much evidence indicates that Pb exposure could directly affect fish growth and development. In this study, we investigated the cytotoxic effect...Inorganic lead （Pb） is one of the most common environmental pollutants. Much evidence indicates that Pb exposure could directly affect fish growth and development. In this study, we investigated the cytotoxic effects of Pb on cytoskeletal protein stability at both protein and mRNA level in crucian carp Carassius auratus. Pb（NO3）2 treatment in concentration of 100 μmol/L resulted in decreased expression of both α- and β-tubulin but γ-tubulin as assayed with SDS-PAGE, Western Blot, and ELISA. In vivo and in vitro analyses on protein expression of tubulins are consistent. The effect of Pb on mRNA expression varied among different tissues. Our results suggest that cytotoxicity of Pb at protein translation level is stronger than at mRNA expression level.展开更多
The kinematics of turning maneuvers of startled Crucian Carp (Carassius auratus) are presented. All escape responses observed are C-type fast-starts. The position of the center of mass and the moment of inertia of the...The kinematics of turning maneuvers of startled Crucian Carp (Carassius auratus) are presented. All escape responses observed are C-type fast-starts. The position of the center of mass and the moment of inertia of the fish are calculated. The results show that the position of the center of mass is always at 35% of the length of the fish from the head and the position of the center of mass and moment of inertia can be considered unchanged during C-start of Crucian Carp. Hydrodynamic analysis of the C-start is given based on the kinematics data from our experiments. The C-start consists of three stages. In stage 1, the tail fin of fish rapidly flaps in one direction, and a large moment acts on the fish′s body, which rotates around the center of mass with an angular acceleration. In stage 2, the tail fin flaps more slowly in the opposite direction at slower speed, the fish′s body rotates around the center of mass with angular deceleration and the center of mass of the fish moves along an arc. In stage 3, the moment approximately equals zero, the fish′s body stops rotating and the center of mass the moves along a straight line.展开更多
A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca（H2PO4）2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochem...A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca（H2PO4）2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochemical parameters, bone and carcass mineral composition, and digestive-enzyme-specific activity in crucian carp（Carassius auratus）.The diets prepared with 0.8%, 0%, and 1.8% Ca（H2PO4）2（1%=1 g/100 g） supplements were regarded as the P1E0, negative control（NC）, and positive control（PC） groups, respectively; the other three experimental diets were prepared with the addition of 200, 300, and 500 U/kg of neutral phytase, respectively, based on the P1E0 group.Three hundred and eighty-four fish（（1.50±0.01） g） were randomly distributed in the six treatments with four replicates each.The fish were initially fed with 2%–3% diets of their body weight per day, with feeding twice daily（08：00 and 16：00）, under a 12-h light/12-h dark cycle at the temperature of（27.56±0.89） ℃.The results showed that supplemental phytase at different levels in the diet improved the final body weight, average daily gain, feed conversion ratio, phosphorus utilization, and protein efficiency ratio of crucian carp（P〈0.05）.Phytase supplementation increased the mineral content in serum（P）, bone（P, Ca）, and carcass（P, Ca, Zn, Na, and Mg）（P〈0.05）; the trypsin and chymotrypsin activity soared when fed with the phytase-supplemented diets（P〈0.05）.We may conclude that supplemental dietary neutral phytase improved the growth performance, phosphorus utilization as well as nutrient utilization in crucian carp, and it can be considered an important nutritional replacement for Ca（H2PO4）2.展开更多
基金Supported by National Natural Science Foundation of China (No.30571414,No 30640015)Changsha Municipal Project of Science and Technology (No.K051127-72).
文摘Inorganic lead （Pb） is one of the most common environmental pollutants. Much evidence indicates that Pb exposure could directly affect fish growth and development. In this study, we investigated the cytotoxic effects of Pb on cytoskeletal protein stability at both protein and mRNA level in crucian carp Carassius auratus. Pb（NO3）2 treatment in concentration of 100 μmol/L resulted in decreased expression of both α- and β-tubulin but γ-tubulin as assayed with SDS-PAGE, Western Blot, and ELISA. In vivo and in vitro analyses on protein expression of tubulins are consistent. The effect of Pb on mRNA expression varied among different tissues. Our results suggest that cytotoxicity of Pb at protein translation level is stronger than at mRNA expression level.
基金This work was supported by the National Natural Science Foundation(No.10332040,10072063)the Innovation Project of the Chinese Academy of Sciences(No.KJCX—SW-L04).
文摘The kinematics of turning maneuvers of startled Crucian Carp (Carassius auratus) are presented. All escape responses observed are C-type fast-starts. The position of the center of mass and the moment of inertia of the fish are calculated. The results show that the position of the center of mass is always at 35% of the length of the fish from the head and the position of the center of mass and moment of inertia can be considered unchanged during C-start of Crucian Carp. Hydrodynamic analysis of the C-start is given based on the kinematics data from our experiments. The C-start consists of three stages. In stage 1, the tail fin of fish rapidly flaps in one direction, and a large moment acts on the fish′s body, which rotates around the center of mass with an angular acceleration. In stage 2, the tail fin flaps more slowly in the opposite direction at slower speed, the fish′s body rotates around the center of mass with angular deceleration and the center of mass of the fish moves along an arc. In stage 3, the moment approximately equals zero, the fish′s body stops rotating and the center of mass the moves along a straight line.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2013AA102803)
文摘A feeding trial was conducted for nine weeks to investigate the effects of partially replacing Ca（H2PO4）2 with neutral phytase on the growth performance, phosphorus utilization, nutrient digestibility, serum biochemical parameters, bone and carcass mineral composition, and digestive-enzyme-specific activity in crucian carp（Carassius auratus）.The diets prepared with 0.8%, 0%, and 1.8% Ca（H2PO4）2（1%=1 g/100 g） supplements were regarded as the P1E0, negative control（NC）, and positive control（PC） groups, respectively; the other three experimental diets were prepared with the addition of 200, 300, and 500 U/kg of neutral phytase, respectively, based on the P1E0 group.Three hundred and eighty-four fish（（1.50±0.01） g） were randomly distributed in the six treatments with four replicates each.The fish were initially fed with 2%–3% diets of their body weight per day, with feeding twice daily（08：00 and 16：00）, under a 12-h light/12-h dark cycle at the temperature of（27.56±0.89） ℃.The results showed that supplemental phytase at different levels in the diet improved the final body weight, average daily gain, feed conversion ratio, phosphorus utilization, and protein efficiency ratio of crucian carp（P〈0.05）.Phytase supplementation increased the mineral content in serum（P）, bone（P, Ca）, and carcass（P, Ca, Zn, Na, and Mg）（P〈0.05）; the trypsin and chymotrypsin activity soared when fed with the phytase-supplemented diets（P〈0.05）.We may conclude that supplemental dietary neutral phytase improved the growth performance, phosphorus utilization as well as nutrient utilization in crucian carp, and it can be considered an important nutritional replacement for Ca（H2PO4）2.
