神农架川金丝猴粪便和尿液中类固醇激素的检测

灵长类动物类固醇激素的研究已经在很多物种间展开(Cariso et al.,1999;Lutz et al.,2000;He et al.,2001;Yan and Jiang,2006;Brandon et al.,2008;Lu et al.,2010;Kim et al.,2012)。特别是对于没有明显发情特征的灵长类动物,类固醇激素的变化可以为它们的繁殖状态提供更多可靠的评估(Fujita et al.,2001)。自然状态下野生动     

哺乳动物细胞去核产物(胞质体及核体)的结构与功能研究

1967年Carter发现细胞松弛素可以诱发组织培养细胞的自发排核之后,Prescott(1972)借助细胞松弛素存在下的离心处理,使这一排核现象普遍化,从而确立了体外细胞去核的标准方法。经过不断改进(croce et al., 1974;Veomett et al., 1976;Lucas etal., 1976;Wigler et al., 1975),现在,这一技术已广泛应用于细胞学研究的各个重要领域(Mc Burney et al., 1979;Goldman et al., 1974;du Bols et al., 1980)。细胞去核技术及其应用的研究在我国已有初步开展(陈瑞铭等,1979;沈鼎武等,1980)。本实验对二种上皮型传代细胞系进行了去核手术,用扫描电镜和透射电镜对所获得的胞质体     

中华鳖精子的超微结构

爬行纲在动物进化中占有重要地位,而且爬行纲动物种类繁多,生态环境和生活习性差异颇为明显。关于爬行动物生殖特性的资料很有限,而且由于动物种类的复杂性,不同动物的研究结果差异较大(Gustavo et al.,2004),缺乏统一的结构模式。精子的形态结构与动物的生殖特性直接相关,在一     

In vivo tunable CRISPR mediates efficient somatic mutagenesis to generate tumor models

Dear Editor, CRISPR/Cas9 has revolutionized genome editing technology due to its simplicity and robustness (Mali et al., 2013). Several inducible CRISPR/Cas9 systems recently developed make spatiotemporal genome editing possible (Kon ermann et al., 2013;Balboa et al., 2015;Dow et al., 2015;Zetsche et al., 2015;Liu et al., 2016;Kleinjan et al., 2017;Maji et al.. 2017;Senturk et al., 2017;Lu et al., 2018).     

圈养大熊猫血清微量元素含量的测定与分析

正微量元素包括Fe、Cu、Cr、Mn和Zn等,虽含量极微,但具有极重要的生理功能,涉及机体的生长发育、免疫代谢等生命活动过程(Shenkin,2008; Subrahmanyam et al.,2015),也是反映机体新陈代谢及生理功能状况的重要指标(Carpene et al.,2017)。例如Fe元素参与机体氧的运输和贮存(Abbaspour et al.,2014),血清铁被认为是动物营养评估的生化指标(Ganapathy et al.,2011); Cu元素是多种氧化酶的重要组分,参与动物新陈代谢、生长发育等(Desai et al.,2014)。     

Persisting lung pathogenesis and minimum residual virus in hamster after acute COVID-19

Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has infected more than 200 million people,causing coronavirus disease 2019(COVID-19)worldwide.Lungs are the primary target organ of SARS-CoV-2 infection.The mild COVID-19 cases develop symptoms of fever,fatigue,muscle weakness,chest pain,headache and cough(Chen et al.,2020;Wang et al.,2020;Zhu et al.,2020),while severe COIVD-19 cases might have pneumonia,breathing difficulties,multiple organ failure and death(Chen et al.,2020;Wang et al.,2020;Zhu et al.,2020).Both the clinicians and researchers have largely focused on the acute phase of COVID-19,but the long-term health consequences of the COVID-19 patients after clinical recovery remain less investigated.Several clinical cohorts demonstrated that some patients discharged from hospital still experience symptoms including fatigue,muscle weakness,chest pain,cough and breathing difficulties(Carfi et al.,2020;Lim et al.,2020;Huang et al.,2021).Moreover,severely impaired pulmonary diffusion capacities and abnormal chest imaging manifestations were observed in some convalescent patients(Huang et al.,2021).Surprisingly,residual virus(An et al.,2020;Yao et al.,2020;Kim et al.,2021)were detected in some convalescent patients.     

Breeding cotton with superior fiber quality: identification and utilization of multiple elite loci and exotic genetic resources

正In the last decade, cotton genomics had great progress in genome assembling(Li et al., 2015; Huang et al., 2020) and agriculturally important locus identification(Du et al., 2018;Ma et al., 2018; Li et al., 2021).Upland cotton(Gossypium hirsutum) is one of the most important cash crops cultivated worldwide. The fiber quality of cotton directly determines its economic value, and therefore enhancing fiber quality is always the primary task in cotton breeding practices(Xia et al., 2019; Huang et al.,2021).     

Import of Rift Valley fever to China: a potential new threat?

正Several recent studies in Virologica Sinica and other journals have highlighted the enormous international challenge of emerging arboviral diseases,such as Zika virus disease,dengue,and chikungunya(Islam et al.,2015;Maurice et al.,2015;Dai et al.,2016;Deng et al.,2016;Song et al.,2016;Wang et al.,2016;Xu et al.,2016;Zhang et al.,2016;Zhou et     

A modified high-efficiency thermal asymmetric interlaced PCR method for amplifying long unknown flanking sequences

<正>Rapid and efficient isolation of unknown flanking DNA sequences adjacent to known regions is important for molecular biology research.For this purpose,several PCR-based methods have been reported,including inverse PCR(Uchiyama and Watanabe,2006),ligation-mediated PCR(Yan et al.,2003;Ballester et al.,2005;Wang et al.,2007;Trinh et al.,2012)and randomly primed PCR(Liu and Whittier,1995;Liu et al.,1995;Antal et al."2004;Liu and Chen,2007;Reddy et al.,2008;Wang     

大鳞副泥鳅雄核单倍体的早期发育

目前,有关鱼类雄核发育的研究已见于川鲽(Platichthys flesus)、马苏大麻哈鱼(Oncorhynchus masou)、虹鳟(Oncorhynchus mykiss)、红点溪鳟(Salvelinus fontinalis)、鲤鱼(Cyprnus carpio)、尼罗罗非鱼(Oreochromis niloticus)、泥鳅(Misgurnus anguillicaudatus)、斑马鱼(Danio rerio)等(Purdom,1969;Arai et al., 1979; Scheerer et al., 1991; May et al., 1988; Bongers et al., 1994;Grunina et al., 1990; Meyers, 1995; Masaoka et al., 1995; 赵振山等,1998;Corley-Smith et al., 1996).     

中国对虾继饥饿后的补偿生长研

1999年7至8月份,在25.0±0.5℃条件下对中国对虾（湿重,1.454±0.150g）进行了不同时间的饥饿处理后再供食的恢复生长实验。对照组C连续饱食投喂32d;处理组S4、S8和S12分别饥饿4、8和12d后再饱食投喂28、24和20d。主要结果如下饥饿结束时各处理组的干重和湿重显著低于对照组（P<0.05）;实验结束时S4组和对照组间的干重和湿重差异不显著（P>0.05）,而S8和S12两组的干重和湿重仍显著低于对照组（P<0.05）;恢复生长后各处理组的湿重摄食率显著高于对照组（P<0.05）。实验结果表明,中国对虾继饥饿后再恢复喂食出现完全或部分补偿生长效应,且这种补偿生长效应主要是通过恢复生长阶段食欲增大,摄食水平提高实现的。     

哲罗鱼稚鱼最佳投喂策略

为探讨哲罗鱼稚鱼的最佳投喂策略,设置了饥饿再投喂试验、饥饿再投喂恢复试验以及日投喂频率试验.结果表明: 饥饿再投喂试验中,各饥饿组未表现出补偿生长现象.但在饥饿再投喂恢复试验中,各饥饿组表现出不同程度的补偿生长,其中S_1/2组(饥饿1/2 d投喂1/2 d)体质量的增加量与对照组接近,表现出完全补偿生长.表明在哲罗鱼早期稚鱼阶段(体质量0～2 g,水温9～15.3 ℃),S_1/2是可以考虑使用的投喂方法.日投喂频率试验中,T₃组(日投喂3次)体长、体质量的增加量以及特定生长率均最高,饵料转化率也相对较高.表明在哲罗鱼后期稚鱼阶段(体质量2～21 g,水温8.8～15.5 ℃),以日投喂3次为宜.     

哲罗鱼稚鱼最佳投喂策略

为探讨哲罗鱼稚鱼的最佳投喂策略,设置了饥饿再投喂试验、饥饿再投喂恢复试验以及日投喂频率试验.结果表明: 饥饿再投喂试验中,各饥饿组未表现出补偿生长现象.但在饥饿再投喂恢复试验中,各饥饿组表现出不同程度的补偿生长,其中S_1/2组(饥饿1/2 d投喂1/2 d)体质量的增加量与对照组接近,表现出完全补偿生长.表明在哲罗鱼早期稚鱼阶段(体质量0～2 g,水温9～15.3 ℃),S_1/2是可以考虑使用的投喂方法.日投喂频率试验中,T₃组(日投喂3次)体长、体质量的增加量以及特定生长率均最高,饵料转化率也相对较高.表明在哲罗鱼后期稚鱼阶段(体质量2～21 g,水温8.8～15.5 ℃),以日投喂3次为宜.     

短期饥饿和再投喂对岩原鲤仔鱼生存生长以及RNA/DNA和RNA/蛋白质比率的影响(英文)

研究通过对岩原鲤仔鱼在饥饿和再投喂条件下其生存、生长率、RNA/DNA和RNA/蛋白质比率的测定,评估了仔鱼对饥饿的耐受能力和恢复能力。在(19.5±0.5)℃水温下,将岀膜后第16天的岩原鲤仔鱼随机分成6个组:1个持续投饲对照组,实验组分别禁食1、2、3、4、5d后再投喂,实验共进行10d。每天分别从各组取9尾鱼测定体重、体长、RNA、DNA、蛋白质含量。实验结果显示,饥饿处理组仔鱼存活率和以上各项生长指标均随饥饿时间的增加而下降,在恢复投喂后均表现不同程度的补偿生长,其中饥饿1、2、3d的仔鱼在恢复投喂后显示出完全补偿生长,几乎弥补了饥饿所产生的影响,平均终体重与对照组比较无显著差异。饥饿4、5d的仔鱼显示部分补偿生长,恢复投喂只少量减轻了饥饿的影响,平均终体重与对照组相比存在显著差异。饥饿1、2、3d的仔鱼和4、5d的仔鱼在恢复投喂后分别需要1—2d和4d时间才能达到与对照组无显著差异水平。仔鱼生长率变动范围从0.59%到8.00%WW/day,仔鱼RNA/DNA比率、RNA/蛋白质比率与生长率的回归方程为:GR=3.63RNA/DNA 1.74(R2=0.80)和GR=120.14RNA/Protein 2.33(R2=0.31),两种比率均与生长率呈显著线性相关,RNA/DNA比率对生长变化的拟合度更好。结果表明,仔鱼阶段食物缺乏很可能是影响岩原鲤仔鱼存活、生长的主要因素。RNA/DNA更适合作为评定岩原鲤仔鱼营养条件和生长的指标。     

完全或部分的食物剥夺对中华鳖(Pelodiscus sinensis)幼体补偿生长反应的影响:生长率的时间变化模式与体组成的变化

为了探究中华鳖（Pelodiscus sinensis）幼体的补偿生长能力,我们对中华鳖幼鳖（平均湿重9．56g）进行如下6种处理：饥饿0（对照）、1、2、3、4周,或者食物限制4周,即只投喂体湿重百分之一的食物;然后对各组进行饱食处理直到10周的实验结束为止。结果发现在饱食期的第一周各饥饿处理组的特殊生长率均显著高于对照组（P〈0．05）,但是终体重均没有赶上对照组。当饥饿或食物限制结束时,脂肪含量随着饥饿期的延长而降低,灰分和水分则表现出相反的变化趋势：脂肪含量显著低于对照（P〈0．05）,而灰分和水分则显著高于对照（P〈0．05）。蛋白含量则没有显著变化（P〉0．05）。实验结束时,除了灰分外（P〈0．05）,其他个体组成指标均恢复到对照组的水平。以上结果表明中华鳖幼体在饥饿胁迫下首先利用脂肪作为主要能源以维持生存,以及在该研究条件下完全的食物剥夺可以诱发其部分补偿生长反应．而部分食物剥夺则不能诱发此反应。     

Lipid metabolism during the initiation of lactation in the rat. The effects of starvation and tumour growth.

1. The effects of starvation post partum (24 h) and tumour growth pre partum on the initiation of lactation in the rat were studied. 2. Tumour growth decreased food intake at 24 h, but not at 2 days post partum. 3. Pup growth rate increased with hyperphagia; starvation and tumour burden decreased pup growth, and starvation decreased maternal body weight. 4. Starvation decreased gastrointestinal-tract mass; tumour growth decreased gastrointestinal-tract and mammary-gland mass. 5. Mammary-gland DNA-synthesis rate was high immediately post partum, but decreased by day 3 of lactation; starvation and tumour burden decreased this rate, and also decreased gastrointestinal-tract DNA-synthesis rate. 6. Arteriovenous differences for glucose and lactate across the mammary gland did not change with time, nor were they affected by the tumour. Starvation decreased arterial glucose and lactate, and the gland extracted less glucose but produced lactate. 7. Mammary-gland lipogenesis was sensitive to starvation and to tumour growth. 8. In contrast with the gradual development of mammary-gland lipogenic enzyme activities, lipoprotein lipase activity was high in the gland by 2 days post partum; starvation or tumour burden decreased the activity. 9. The mammary gland is sensitive post partum to decreased food intake, and to tumour presence. The effects of the latter are apparently independent of hypophagia.     

Effect of starvation and refeeding on digestive enzyme activities in juvenile roach, Rutilus rutilus caspicus

We evaluated the effects of starvation and refeeding on digestive enzyme activities in juvenile roach, Rutilus rutilus caspicus. Fish were divided into four feeding groups (mean mass 1.68 ± 0.12 g). The control group was fed to satiation twice a day throughout the experiment with formulated diet (SFK). The other three groups were deprived of feed for 1(S1), 2(S2), and 3(S3) weeks, respectively, and then fed to satiation during the refeeding period. The results showed that trypsin specific activity was not affected significantly either by starvation or refeeding, in all experimental groups. Chymotrypsin specific activity did not change significantly in S1 fish during the experimental period. In S2 and S3 fish no significant changes were observed during the starvation period. Upon refeeding, the activity increased in S2 fish, while it decreased in S3 fish. Amylase specific activity decreased significantly during the starvation period in all experimental groups. Upon refeeding, the activity increased. Alkaline phosphatase specific activity did not change significantly during the experiment period in S3 fish, while it showed significant changes during the starvation and refeeding period in the S1 and S2 fish. Starvation also had a significant effect on the structure of the intestine.     

Compensatory growth in sub‐yearling Siberian sturgeon,Acipenser baerii Brandt, 1869: Effects of starvation and refeeding on growth,feed utilization and body composition

The capacity of sub‐yearling Siberian sturgeon (Acipenser baerii Brandt, 1869) (19.7 ± 0.8 g) to show compensatory growth was assessed for a 40‐day period for the effects of short‐term starvation and refeeding on growth, feeding performance and body composition. After acclimation, 25 experimental fish were randomly distributed among twelve 500‐L cylindrical fiberglass tanks with a flow‐through system. The fish were subjected to four different feeding regimes: control, which was fed four times daily to apparent satiation; T₁: four periods of 2 days starvation alternating with 8 days re‐feeding; T₂: two periods of 4 days starvation alternating with 16 days refeeding; T₃: an 8 days starvation period followed by 32 days refeeding. At the end of the experiment, the deprived fish attained body weights comparable to those attained by the control fish. There were no differences in growth and feeding performances between the deprived and the control fish. Total protein and lipid contents of the control fish were significantly higher than that of T₁ and T₂ fish at the end of the experiment (P < 0.05). A significant difference in the energy content was observed between T₂ and the control. Siberian sturgeon exhibited complete compensation, indicating a high ability of the deprived fish to grow sufficiently to fully compensate for weight loss during starvation. The results suggested that the feeding schedule involving starvation–refeeding cycles could be a promising feed management option for the culture of this species.     

An experimental manipulation of food and water: growth and time-space utilization of hatchling lizards (Sceloporus undulatus)

Summary At a site in western Nebraska, we studied the effects of supplemental food and water on growth, survival, and habitat utilization of hatchling iguanid lizards, Sceloporus undulatus. Hatchlings were randomly assigned to one of four experimental groups and received either (1) supplemental food only, (2) supplemental water only, (3) supplemental food and water, or (4) neither supplemental food nor water (control). Neither supplemental food nor supplemental water affected growth rate in length, growth rate in mass, or size-specific body mass (i.e. robustness) at the end of the treatment period. Over the 45 day treatment pierod, there were no significant differences among treatment groups in survival, home-range size, or habitat utilization. There were, however, significant differences in the index of activity. Hatchlings in the treatment groups receiving supplemental water were sighted more often than hatchlings in the control group. We conclude that, during our study, neither food nor water limited growth but that water limited activity.     

Anthropometrical parameters and markers of obesity in rats

The present study was undertaken to determine anthropometrical parameters in male adult Wistar rats. We tested the hypothesis that the anthropometrical index may identify obesity and may predict its adverse effects on lipid profile and oxidative stress in rats. Two experimental protocols were performed. In the first experiment, 50 male Wistar rats, 21 days old and fed a control chow were studied up to 150 days of age. In the second experiment, male Wistar rats, 60 days old, were divided into three groups (n = 8): control (C) given free access to a control chow; (S) receiving the control chow and drinking 30% sucrose ad libitum and (HC) fed a high-carbohydrate diet ad libitum. The first experiment showed that food consumption, energy intake and body weight increased with increasing age, while specific rate of body mass gain was significantly decreased. There were no significant differences in body length and thoracic circumference of rats from 60 days of age. The abdominal circumference (AC) and body mass index (BMI) significantly increased with enhancing age in rats up to 90 days of age and remained constant thereafter. In the second experiment, after 30 days of dietary treatment, the final body weight, body mass gain, carcass fat and BMI were higher in S and HC rats than in C. There were no significant alterations in body length and carcass protein among the groups. Triacylglycerol (TG), total cholesterol (CT), low-density lipoprotein cholesterol (LDL-C) and lipid hydroperoxide (LH) were higher in S and HC rats than in C. High-density lipoprotein cholesterol (HDL-C) decreased in HC rats and total antioxidant substances (TAS) decreased in S and HC rats. There were positive correlations between BMI with carcass fat, BMI with LH and BMI and serum TG concentration. In conclusion, the BMI for male adult Wistar rats ranged between 0.45 and 0.68 g/cm(2). Obesity may be easily estimated from the BMI in rats. Alterations in BMI were associated with dyslipidemic profile and oxidative stress in serum of rats and BMI may predict these adverse consequences of the obesity in rats.