南方大口鲇幼鱼发育的初步研究

南方大口鲇的人工孵化鱼苗在11日龄时卵黄消失,转入营外生性营养的仔鱼阶段;23—26日龄仔鱼的主要外部器官分化完毕,转入稚鱼阶段;40—43日龄稚鱼除存在第二下颌须外,其余外形特征与成鱼相似,稚鱼阶段结束. 5月上旬在嘉陵江中采获到的当年幼鱼已发育到稚鱼阶段结束时期的水平;6—7月的当年幼鱼,当体长为151—177毫米时,第二下颌须消失.当年幼鱼体重和体长的关系为: W=e-10.87062L2.74257(N=77,r=0.9952)根据尾形、体色和须的数量的差异,可以区别南方大口鲇和鲇的当年幼鱼.       

饲料碳水化合物水平对南方鲇幼鱼餐后糖酵解酶活性及血糖浓度的影响

配制含0%、15%和30%糊化玉米淀粉的等能饲料分别作为对照、中水平和高水平碳水化合物(CHO)饲料,以体重为50.5±0.6g的南方鲇幼鱼为实验对象,在水温27.5±0.5℃的条件下以对照饲料驯化15d后,分别测定了以三种饲料投喂的南方鲇在餐后3、61、2、24和48h的己糖激酶(HK)、葡萄糖激酶(GK)和磷酸果糖激酶(PFK-1)的活性和血糖水平。结果发现,中、高水平CHO组HK活性在餐后24h时显著高于对照组(P<0.05),其余时间点各组间无显著差异;GK活性随CHO水平增加而增加,但其活性的绝对值远低于HK;PFK-1活性在各组间及同组内各时间点均无显著差异。通过分析认为,南方鲇体内葡萄糖磷酸化主要由HK催化,但其活性受饲料CHO水平的影响不明显;GK活性受饲料CHO的诱导而增高,使葡萄糖磷酸化加速,但最大增幅不超过30%;此外,催化果糖-6-磷酸进一步转化为果糖-1,6-二磷酸的PFK-1活性不受饲料CHO水平的影响,因此糖酵解过程的这两个代谢环节均不能在鱼体吸收高糖营养后有效地加速,这应当是该肉食性鱼类在高水平CHO营养条件下产生高血糖积累的重要原因。实验结果表明,血糖变化呈现先升高后降低的趋势,中水平和高水平CHO组的血糖峰值均出现在餐后12h,这作为在该类研究中设定血液取样时间的实验依据。     

深水网箱养殖卵形鲳鲹血液指标

对深水网箱养殖卵形鲳鲹(Trachinotus ovatus)成鱼的部分血液性状和血清生化指标进行测定比较.结果显示,雌、雄成鱼红细胞数量(RBC)、白细胞数量(WBC)、血细胞比容(Ht)、红细胞沉降率(ESR)等血液性状不存在显著性差异.血清指标中雌、雄成鱼血糖(GLU)的含量分别为(10.24±1.25)mmol/L、(17.36±1.34)mmol/L,存在极显著差异;雌鱼血清中低密度脂蛋白胆固醇(LDL-C)、钾离子(K+)、谷丙转氨酶(ALT)、谷草转氨酶(AST)浓度大于雄鱼(P<0.05);雄鱼血清中肌酐(CREA)、钠离子(Na+)浓度大于雌鱼(P<0.05);尿酸(UA)、尿素氮(BUN)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、γ-谷氨酰转肽酶(γ-GT)、总蛋白(TP)、白蛋白(ALB)、球蛋白(GLB)、白蛋白/球蛋白(ALB/GLB)、钙离子(Ca2+)、氯离子(Cl-)、无机磷(PO43-)等指标,雌雄差异不显著.卵形鲳鲹部分生化指标存在雌雄差异,可能与个体的生理状况有关.结果可为卵形鲳鲹血液生理研究提供基础资料.     

南方鲇不同组织间线粒体代谢的比较研究

采用人工繁殖的同批南方鲇(Silurus meridionalis Chen)幼鱼为研究对象,分别在7.5、10、12.5、17.5、22.5、27.5、32.5、35和37.5℃条件下测定其心脏、肾脏、肝脏、脑和白肌的线粒体呼吸率、细胞色素c氧化酶(CCO)的活性,以检测不同组织线粒体的含量及代谢特征的差异性。在27.5℃下,南方鲇心脏、肾脏、肝脏、脑和白肌线粒体状态3呼吸率分别为69.94、30.98、32.36、18.89和7.34 nmol O2/min.mg;CCO活性分别为676.54、327.46、294.34、153.23和65.73 nmol O2/min.mg。统计检验表明,状态3呼吸率和CCO活性均表现为:心脏显著高于其他4种组织(P<0.05),白肌则要显著低于其他4种组织(P<0.05),肾脏和肝脏之间差异不显著,但均显著高于脑(P<0.05)。试验测定了以上5种组织的柠檬酸合酶(CS)活性来表征组织中线粒体含量。在27.5℃条件下CS的活性则分别是17.93、7.20、8.42、6.12和1.35 U/mg,心脏显著高于其他4种组织(P<0.05),肝脏、肾脏和脑之间差异不显著,但都显著高于白肌(P<0.05)。在7.5℃—32.5℃范围内,南方鲇的心脏、肝脏、肾脏、脑和白肌5种组织的线粒体状态3呼吸率和CCO活性均随着温度的升高而增加,但在高温端,心脏中这两种代谢指标开始出现随温度上升而下降的趋势。在低温端(7.5℃—10℃)和高温端(35℃—37.5℃),各组织线粒体呼吸率RCR值多数小于4,在37.5℃下的心脏和7.5℃下的白肌的RCR值分别低至1.76和1.85。研究结果提示,南方鲇不同组织间线粒体含量可以由CS活性作为间接指标进行比较,而各组织间线粒体含量及其代谢能力存在较大的差异。心脏表现出高含量、高代谢能力和低的耐受高温能力;白肌为低含量、低代谢能力和低的耐受低温能力;肝脏、肾脏和脑表现为中等含量、中等活性和较高的耐受极端温度能力。     

饲料淀粉水平对南方鲇免疫的影响

为研究饲料碳水化合物水平对南方鲇免疫力的影响,配制含0%、15%和30%糊化玉米淀粉的等能饲料分别作为对照、中水平和高水平碳水化合物（CHO）饲料,以体重为20.7±0.5g的南方鲇幼鱼为实验对象,在水温27.5±0.2℃的条件下以对照饲料驯化15d后,测定以3种饲料投喂02、、48、、12和16周时南方鲇鱼体的血清溶菌酶活性、抗菌活性和血清总蛋白含量。结果发现,中水平CHO组血清溶菌酶活性在4周和12周时显著低于对照组（p〈0.05）,其他各时间点均与对照组无显著差异;高CHO组在2—12周期间均显著低于对照组（p〈0.05）,而在16周时与对照组之间差异不显著。从第4周到第16周,中、高CHO组血清抗菌活性均显著低于对照组（p〈0.05）,而中、高CHO组之间在各时间点均无显著差异。在16周时,中CHO组和高CHO组血清总蛋白含量显著高于对照组（p〈0.05）,在其余时间点三组间差异均不显著。以上结果表明：饲料中含15%的CHO对南方鲇生长无显著影响,但明显抑制了鱼体免疫力,且免疫抑制作用随碳水化合物水平的提高而加强。综合分析本研究的结果提出,饲料碳水化合物是抑制南方鲇免疫力的一个重要因子。提高溶菌酶类蛋白质的合成速率是该种鱼在长期饲料CHO营养胁迫下的适应机制之一,表观上反映为血清蛋白含量的升高。通过比较观察饲料CHO对南方鲇生长和免疫力的抑制作用,提出应当综合二者的观测结果来评价CHO饲料对鱼类的营养胁迫及适合状况。     

饲料中添加磷虾水解物对大菱鲆幼鱼生长性能、体组成及相关酶活性的影响

选取初始体重为(9.46±0.01) g的大菱鲆(Scophthalmus maximus L.)为研究对象, 以30%鱼粉组为对照, 分别添加5%磷虾水解物(LKH)和10%磷虾水解物(HKH)以替代鱼粉蛋白, 配制3组等氮等脂的饲料, 在室内流水养殖系统进行为期10周的养殖实验, 旨在探究饲料中添加磷虾水解物对大菱鲆幼鱼生长性能、体组成及相关酶活性的影响。结果显示, HKH组大菱鲆幼鱼的特定生长率(SGR)、饲料效率(FE)、蛋白质效率比(PER)、蛋白质沉积率(PPV)均显著高于对照组(P<0.05), 但摄食率(FI)显著低于对照组(P<0.05); LKH、HKH组大菱鲆幼鱼肌肉总氨基酸含量和必需氨基酸含量显著高于对照组(P<0.05); LKH、HKH组肝脏谷草转氨酶(GOT)活性显著高于对照组(P<0.05), 而血清GOT活性与对照组无显著性差异(P>0.05); HKH组肝脏谷丙转氨酶(GPT)活性显著高于对照组和LKH组(P<0.05), 但血清GPT活性显著低于LKH组和对照组(P<0.05); HKH组肠道淀粉酶活性显著高于对照组(P<0.05), 同时随着磷虾水解物添加量的升高, 肠道及幽门盲囊胰蛋白酶活性先降低后升高, 且在HKH组显著高于对照组(P<0.05)。综上结果表明, 在饲料中添加10%磷虾水解物能够提高大菱鲆幼鱼的生长性能, 促进其氨基酸代谢和消化吸收。     

饲料中添加丝兰提取物对大菱鲆幼鱼生长和生理及水环境的影响

用丝兰提取物添加量为0.00% (D0)、0.05% (D1)、0.10% (D2)、0.20% (D3)和0.40% (D4)的实验饲料投喂大菱鲆幼鱼(42.200.06) g 60d, 研究其对大菱鲆幼鱼生长性能、体组成、血清免疫代谢指标及养殖水质指标的影响。结果显示, 在饲料中添加丝兰提取物对大菱鲆幼鱼增重率(WGR)、特定生长率(SGR)、饲料系数(FCR)、脏体比(VSI)、肝体比(HSI)、肥满度(CF)均无显著影响(P 0.05)。全鱼、肌肉及肝脏中水分、粗蛋白、粗脂肪含量变化无显著性差异(P 0.05)。D3组幼鱼血清溶菌酶显著高于其他各组(P 0.05), 而D4组各免疫指标明显低于对照组(P 0.05); D3和D4组幼鱼血清的谷丙转氨酶(ALT)、谷草转氨酶(AST)活力显著低于对照组。除A1-6h组外各实验组水体氨氮含量均显著低于对照组(P 0.05), 各实验组亚硝酸盐含量均显著高于对照组(P 0.05), 各实验组总氮、总磷、磷酸盐含量均与对照组无显著性差异(P 0.05)。研究证明, 在饲料中适量添加丝兰提取物能够显著增强大菱鲆幼鱼非特异性免疫能力, 并显著降低养殖水体氨氮含量, 对大菱鲆生长及体组成无显著影响。以非特异性免疫及水体氨氮含量为综合评定指标, 大菱鲆幼鱼饲料中丝兰提取物的适宜添加量为0.20%。       

光色对豹纹鳃棘鲈(Plectropomus leopardus)幼鱼生长及血液生化指标的影响

为了探索光色对鱼类的生长和血清生化指标的影响,利用一个小型循环水养殖系统中的不同养殖水槽,设置了白光、红光、黄光、绿光和黑暗5种光照环境,对豹纹鳃棘鲈(Plectropomus leopardus)幼鱼(体长19.67±1.26 cm,体质量92.92±4.05 g)进行了120 d的养殖实验。结果表明:光色对豹纹鳃棘鲈的生长和存活的影响存在显著性差异,绿光组幼鱼的存活率和体质量均最大,白光组幼鱼的肝胰脏指数(HSI)最高;白光组幼鱼的血糖、血脂和蛋白质的含量均低于其他4组;白光组幼鱼的谷丙转氨酶(ALT)、谷草转氨酶(AST)和乳酸脱氢酶(LDH)的含量最高,白光组幼鱼的LDH显著高于红光组和绿光组;白光组幼鱼的肌酐(CREA)和尿素氮(BUN)含量高于其他4组(P0.05);5种光色下的幼鱼血液中的无机离子含量除Mg~(2+)外,Ca~(2+)、P~(3+)、Na~+和K~+均无显著性差异。综合生长、存活及血清生化指标分析,5种光色中,绿光最适宜豹纹鳃棘鲈幼鱼生长和存活。     

南方鲇的营养学研究:饲料中大豆蛋白水平对生长的影响

以初始体重为 2 3 .78± 0 .0 9g的南方鲇幼鱼为实验对象 ,在室内循环水养殖系统中进行为期 6周的生长实验。以大豆蛋白分别替代 0 %、1 3 %、2 6 %、3 9%、5 2 %和 6 5 %的鱼粉蛋白 ,配制成 6种等氮 (粗蛋白为 48%)、等能 (总能 2 0 KJ/ g)的饲料 ,用于探讨饲料中鱼粉蛋白与大豆蛋白的不同比例对南方鲇生长及饲料转化率的影响。实验在 2 7.5± 0 .2℃水温条件下进行 ,溶氧维持在 5 mg/ L以上 ,光照周期为 1 4L:1 0 D。实验结果表明 ,当大豆蛋白分别替代1 3 %、2 6 %和 3 9%的鱼粉蛋白时 ,3组之间的特定生长率 (SGR)的差异不显著 (P>0 .0 5 ) ,但均显著高于 5 2 %和 6 5 %替代水平 (P<0 .0 5 )。其中 1 3 %和 2 6 %的替代水平的特定生长率(SGR)显著高于对照组 (P<0 .0 5 ) ;3 9%替代水平的特定生长率 (SGR)与对照组之间差异不显著 (P>0 .0 5 ) ;而 5 2 %和 6 5 %替代水平的特定生长率 (SGR)则显著低于对照组 (P<0 .0 5 )。饲料转化率 (FCE)、蛋白质效率 (PER)和蛋白质累积率 (PPV)分别在各处理组之间的差异关系与特定生长率 (SGR)在各组之间的变化相类似。因此 ,本文提出南方鲇饲料中大豆蛋白替代 3 9%的鱼粉蛋白是适宜的 ,过量的添加将影响南方鲇的生长及饲料转化率。通过分析认为大豆蛋白影响南方鲇生     

南方鲇的营养学研究:饲料中大豆蛋白水平对消化率及摄食率的影响

以23.78±0.09g的南方鲇为实验对象,以Cr2O3作为测定饲料消化率的指示物,以大豆蛋白分别替代0%、13%、26%、39%、52%和65%的鱼粉蛋白,配制成6种等氮(粗蛋白48%)、等能(总能20KJ/g)的饲料,用于探讨饲料中大豆蛋白替代鱼粉蛋白的比例对南方鲇消化率及摄食率的影响。实验在27.5±0.02℃水温条件下进行6周,溶氧维持在5mg/L以上,光制为14L∶10D。结果表明,饲料中不同比例的鱼粉蛋白与大豆蛋白对南方鲇的消化率及摄食率均存在显著影响(P<0.05)。其中南方鲇对于物质、蛋白质、脂肪和能量的消化率随着大豆蛋白替代率的提高而逐步下降,当替代量为65%时,其消化率显著低于其余各组(P<0.05)。而南方鲇的摄食率均随着饲料中大豆粉添加量的升高而升高,当大豆蛋白替代鱼粉蛋白超过39%时,摄食率显著高于其余各组(P<0.05)。通过分析认为,消化率是限制南方鲇利用大豆粉的重要因素,而摄食率不是影响其利用率的主要原因。     

粘虫幼虫密度对成虫能源物质含量的影响

通过粘虫Mythimna separata幼虫密度(1头/瓶、20头/瓶、40头/瓶)对成虫水分、甘油酯和糖原含量影响的研究结果。不同幼虫密度处理的初羽化成虫水分含量无明显差异,但1～5日龄40头/瓶的雄蛾及1～3日龄雌蛾高于单头处理的;20、40头/瓶的初羽化成虫甘油酯含量没有显著的差异,但均显著地高于单头饲养的;20头/瓶羽化的雌、雄成虫l～5日龄甘油酯含量随日龄的增加而增加,到5日龄达到最大值后才开始下降,40头/瓶的在3日龄达到最大值后即开始下降,而单头饲养羽化的在1日龄达到较高值,2日龄降至最低后再缓慢回升。幼虫密度对初羽化成虫及1～7日龄雄蛾的糖原含量没有显著的影响,但20、40头/瓶条件下羽化的1～7日龄雌蛾糖原含量随日龄的增加而增加,而单头饲养的则随日龄的 增加而下降。这些结果表明幼虫密度不仅影响到初羽化成虫能源物质的含量,而且也可能影响到成虫能源物质特别是甘油酯的代谢。     

Life table parameters, reproductive rate, intrinsic rate of increase, and estimated cost of rearing Podisus maculiventris (Heteroptera: Pentatomidae) on an artificial diet.

The impact of an insect-free artificial diet provided at nymphal and/or adult stage upon the developmental rate, life table parameters, and fertility table parameters was examined for Podisus maculiventris (Say). This study showed that when fed an insect-free artificial diet during both the nymphal and adult stage, developmental time was prolonged, preoviposition period was extended, and reproductive rate (R0) and intrinsic rate of increase (r) were significantly lower than when fed larval insect prey at both nymphal and adult stages. Additionally, feeding larval prey to adults reared as nymphs on an artificial diet significantly increased the proportion of fertile females, the number of eggs laid by mated females, the reproductive rate and intrinsic rate of increase, but the mean generation time was not significantly different. Likewise, feeding artificial diet to adults reared on larval prey resulted in a significant reduction in reproductive rate and intrinsic rate of increase. The "realized" cost to rear P. maculiventris on the artificial diet was calculated (as the cost to double the population size) using raw material cost, fertility table parameters and doubling time values. Raw material cost for rearing P. maculiventris colony on Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) was only 1.4 times higher than the cost of artificial diet raw materials required to rear the same size colony. However, the realized cost of rearing was 3.5 times higher when rearing on artificial diet because of the prolonged developmental time and reduced reproductive output. The cost efficiency of rearing a beneficial insect on an artificial diet that decreases the intrinsic rate of increase of a colony is discussed, as well as the advantages and disadvantages of supplementing adult diets with natural prey at the reproductive stage.     

Dietary glycerol and adult access to water: effects on fecundity and longevity in the almond moth

The quality of food eaten by larval insects will affect traits such as gamete production, fat reserves, muscle bulk and body size in the adult. Moreover, larvae also depend on high moisture content in the diet for survival. The almond moth (Ephestia cautella) (W.) (Lepidoptera; Pyralidae) does not feed as an adult although it continues to drink water. We tested the idea that an almond moth could compensate for a low-water diet as a larva by increasing its water intake as an adult. We reared larvae on two different food sources with different moisture regimes; standard laboratory diet with glycerol (relatively wet) and standard diet without glycerol (relatively dry). Half the adult moths from each treatment were given water to drink before their first and only mating. Our results show that wet larval diets (i.e. containing glycerol) significantly decreased fecundity (total number of eggs laid and the proportion of hatched larvae), whilst it significantly increased male and female longevity. The interaction effect of water access for adult males and females was significant, independent of the glycerol in the larval diet. Longevity in females that were not presented with water as adults was slightly higher if mated with a male that had had access to water, suggesting a mating donation of water. However, females that received water as adults showed a decreased longevity if mated with a male who had also had access to water as an adult, indicating a negative effect of water if received by both males and females. In addition, when the larval diet included glycerol, increased number of eggs laid decreased female longevity, whilst an absence of glycerol in the larval diet resulted in low female longevity that was unlinked with fecundity. Glycerol is used in many artificial insect diets and the fact that it shows a strong effect on key life-history traits (reproductive output and longevity in this species), merits careful re-examination of its effects on these important traits in other laboratory models. We also discuss the possibility that larval diet can affect female reproductive decisions.     

幼虫密度对甜菜夜蛾生长发育与繁殖的影响

为了研究甜菜夜蛾Spodoptera exigua(Hübner)幼虫的密度对其发育及繁殖的影响,本实验观察了5种幼虫密度下（1,5,10,20,30头/瓶）,幼虫发育和成虫繁殖情况。结果表明：幼虫和蛹历期、存活率和蛹重均差异显著。幼虫和蛹历期均以20头/瓶的最短,1头/瓶的最长,其余随幼虫密度增加而延长;幼虫至蛹存活率以10头/瓶的最高,其余随幼虫密度增加而降低;1头/瓶的蛹最重,显著高于其他密度的,其余随幼虫密度增加而下降。尽管密度间成虫羽化率和产卵前期均无显著差异,但成虫产卵量、寿命和畸形率差异显著。1头/瓶的产卵量最多,其次为10头/瓶的,其余随幼虫密度增加而减少,30头/瓶的产卵量显著少于其他密度的; 密度在1～20头/瓶范围内,雌蛾寿命均较短,显著短于30头/瓶的,而雄蛾寿命以5头/瓶的最短,显著短于其他密度的（10头/瓶除外）,10头/瓶的次之,其余密度间差异不显著;不同幼虫密度下羽化的成虫畸形率差异显著,10头/瓶的最低,其余随幼虫密度增加而升高; 生命表结果表明甜菜夜蛾在10头/瓶下世代存活率和种群增长指数均最高,幼虫密度过低或过高均不利于种群增长;世代存活率（S）和种群增长指数（I）与幼虫密度之间的关系均呈抛物线关系：S =－0.2087x²+2.5694x+211.52 (R²=0.88),I=－0.0552x²+0.9166x+54.168 (R²=0.95)。结果提示幼虫密度影响甜菜夜蛾种群动态的重要生态因子之一。     

Induction of glutathione S-transferase in the castor semilooper,Achaea janata (lepidoptera,Noctuidae) following fenitrothion treatment

Glutathione S-transferase activity was determined in the lepidopteran insect species,Achaea janata, during larval, pupal and adult stages following treatment with sublethal and lethal doses of fenitrothion. Both doses of insecticide produced significant induction of enzyme activity. The rate of induction of enzyme activity was not significantly different in insects that received sublethal and lethal doses of insecticide. Enzyme activity in the different stages of insecticide-treated insects was in the order pupa > adult > larva. However, the inducing effect of the insecticide was higher in larvae, than in pupae and adult. In the absence of induction, the level of enzyme was as much as 3 times higher in midgut tissue than in carcass. In larvae treated with sodium barbitone along with fenitrothion, the knock-down effect of the insecticide was delayed. This was attributed to the increased induction of glutathione S-transferase in the larvae treated with sodium barbitone. The level of reduced glutathione, a rate-limiting factor in the induction of glutathione S-transferase, changed in a cyclic manner in insecticide-treated larvae.     

不同性别和生长阶段对克氏原螯虾肠道菌群多样性的影响

为研究性别和生长阶段对克氏原螯虾(Procambarus clarkii)肠道菌群的影响, 实验对来自虾塘的雌雄成虾肠道样品及来自实验室养殖的幼虾和成虾的肠道样品进行了16S rRNA高通量测序分析。结果表明, 不同性别间克氏原螯虾肠道菌群的多样性和功能均没有显著性差异(独立样本t检验: P>0.05), 其优势菌群在门水平上均包括厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)等; 属水平上包括拟杆菌属(Bacteroidia)、希瓦氏菌属(Shewanella)、梭菌属(Clostridium)和柠檬酸杆菌属(Citrobacter)等; 但各优势菌群在个体间的丰度差异较大, 且在成虾阶段趋于保守, 属肠道常驻菌群。幼虾肠道菌群的Alpha多样性显著高于成虾(独立样本t检验: P<0.05)。在门水平上, 优势菌群较为一致, 包括变形菌门、拟杆菌门、厚壁菌门和放线菌门(Actinobacteria)。成虾厚壁菌门与拟杆菌门的比例高于幼虾, 表明成虾分解食物和吸收营养的潜力更强。在属水平上, 成虾和幼虾肠道中均存在大量的黄杆菌属(Flavobacterium)、拟杆菌属和氢噬胞菌属(Hydrogenophaga), 这些菌属可以帮助机体进行多种营养代谢, 成虾肠道中与碳水化合物代谢相关的菌群多于幼虾。PICRUSt功能预测显示, 在克氏原螯虾肠道中, 营养代谢功能相关的菌群相对丰度最高, 而成虾肠道菌群代谢碳水化合物的功能显著高于幼虾。实验表明, 在野外虾塘养殖下的克氏原螯虾的肠道菌群不论是在群落多样性、物种丰度还是菌群功能预测上, 都未体现出性别间的差异, 且肠道菌群的个体差异较大; 但在不同生长阶段间, 克氏原螯虾肠道微生物的群落多样性、丰度及功能都有显著差异, 相比于幼虾, 成虾肠道菌群多样性降低, 多种代谢功能升高。     

Serum biochemical values in fallow deer (<Emphasis Type="Italic">Dama dama</Emphasis> L.) from different habitats in Croatia

Serum biochemical values were determined in blood samples collected from 48 shot fallow deer from the Brijuni islands and 45 sedated fallow deer (Dama dama L.) from hunting grounds in the continental part of Croatia. The parameters were compared with regard to age, sex and habitat. Statistically significant differences were found for serum total protein concentration, alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activity between young and adult island deer, as well as for total protein, triacylglyceride, cholesterol concentration and alkaline phosphatase activity between young and adult continental deer. In young animals, island males had higher albumin concentrations, while continental males had higher alkaline phosphatase values than females. In adult animals, island males had a higher blood urea nitrogen concentration, while continental males had higher albumin and cholesterol concentrations, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and creatine kinase activities. In this group, males exhibited lower bilirubin and triacylglyceride concentrations than females. Our results indicate that besides age, sex and sampling method, nutritional and environmental factors should be considered when evaluating serum biochemical parameters of fallow deer     

Biochemistry of development in insects. Incorporation of fatty acids into different lipid classes.

1. To study the different metabolic behaviour of various stages of development of the insect Ceratitis capitata, the incorporation of labelled decanoic, lauric, myristic, palmitic, stearic, oleic, and linoleic acids into triacylglycerols by insect homogenates was investigated. The time-course of incorporation of labelled fatty acids was firstly studied by using oleic acid; it showed that after 10 min of incubation the levels of radioactivity incorporated into triacylglycerols and those remaining in the free fatty acids were practically unchanged. 2. All labelled fatty acids were efficiently incorporated by larval homogenates; however, most of the radioactivity remained as free fatty acids in the presence of pharate adult homogenates, palmitic, and stearic acids being the most scarcely incorporated by this stage of development of the insect. 3. Plots of triacylglycerol and free fatty acid radioactivites versus the stage of development defined a crossing-zone in coincidence with the larval-pupal apolysis. This metabolic difference between larval and pharate adult homogenates could not be explained through differences in the acyl-CoA synthetase activity of the insect; this enzyme activity was notably higher in pharate adult homogenates than in the larval homogenates whatever would be the nature of the fatty acid. 4. [14C]Triolein was scarcely hydrolyzed by both larval and pharate adult homogenates. 5. Double-label experiments were carried out by incorporating either [3H]oleic acid or [3H]-palmitic acid and [14C]glycerol 3-phosphate by larval and pharate adult homogenates at different incubation intervals. Diacylglycerols, triacylglycerols, and phosphoglycerides were isolated and the 14C/3H molar ratio calculated. Results suggest the existence of a different acyltransferase activity in the different stages of development of the insect.     

Cytochrome oxidase activity during diapause and metamorphosis of the Japanese beetle,Popillia japonica Newman

1. Determinations were made on the activity of cytochrome oxidase of individual Japanese beetles during growth, diapause, and metamorphosis. All readings were made on homogenates at a dilution of 1:1,000, except for adult beetles, when the final dilution was 1:10,000. 2. The activity of the enzyme increased during larval growth from a low value of 0.022 in the second instar, to high values ranging from 0.074 to 0.083 in diapause third instar larvae. 3. The high activity of cytochrome oxidase during larval diapause indicates that this condition may be physiologically different from that occurring in the egg or pupal stages of most other insects. 4. During metamorphosis, the activity of cytochrome oxidase follows the characteristic U-shaped curve associated with respiratory metabolism. It thus appears that most of the oxidation occurring in metamorphosing individuals is mediated through the cytochrome system. 5. The activity of cytochrome oxidase is significantly higher in the adult male than it is in the adult female; the values (calculated on the basis of a 1:1,000 dilution) were 0.40 ± 0.028 and 0.25 ± 0.012, respectively.     

Distribution of glutamine hexosephosphate aminotransferase in rat tissues; changes with state of differentiation

The activity of glutamine hexosephosphate aminotransferase (L-glutamine: D-fructose 6-phosphate aminotransferase, EC 2.6.1.16) was determined with an improved assay method in some three dozen rat tissues: adult, developing and neoplastic. The highest activities (20–200 units/g) were seen in colon, mammary (during late lactation), submaxillary, sublingual and parotid glands, placenta and liver. The activity increased strikingly along the length of the intestine; glucose feeding inhibited it in ileum and colon. In liver and intestine the activity increased with age but in brain, muscle, heart and kidney the activity was considerably higher during fetal (7.1–12.8 units/g) than in adult life (0.8–3.5 units/g). Renal, mammary and muscle tumors (but not hepatomas) had much higher activities (4–20.5 units/g) than the cognate normal adult tissue.The distribution pattern among tissues indicates that glutamine hexosephosphate aminotransferase is of general importance to all growing, undifferentiated tissues and of special importance to the differentiated function of particular adult organs. The latter are organs which engage in glycoprotein secretion. The results support the assumption that glutamine hexosephosphate aminotransferase activity is essential for glycoprotein synthesis.