营养盐浓度对棕鞭藻叶绿素荧光参数、细胞密度和总脂含量的影响

利用生物化学方法和叶绿素荧光动力学分析技术,研究了棕鞭藻在一次性培养过程中,不同营养盐浓度(f/4、f/2、f、2f、4f)对其叶绿素荧光参数、叶绿素含量、细胞密度、单位体积干质量、总脂含量和总脂收获量的影响。试验结果表明,营养盐浓度为2f时,该藻的最终细胞密度、叶绿素含量、单位体积干质量、总脂含量和总脂收获量均显著高于其他各处理组,由此可以看出,在本试验条件下,最适合棕鞭藻生长和油脂积累的营养盐浓度是2f。不同营养盐浓度对棕鞭藻的叶绿素荧光参数有显著影响,培养6～10d,f/4处理组的叶绿素荧光参数(光系统Ⅱ的最大光能转换效率;光系统Ⅱ的潜在活性;光系统Ⅱ的实际光能转化效率;相对电子传递效率和光化学淬灭)最低,其次为f/2处理组(P0.05)。培养7～10d,2f处理组的光系统Ⅱ的实际光能转化效率、相对电子传递效率和光化学淬灭显著高于其他处理组(P0.05)。培养结束时(第10d),各处理组细胞密度和总脂含量依次为:2f4fff/2f/4。相关性分析结果表明,营养盐浓度为f/4～2f时,棕鞭藻的细胞密度、叶绿素含量、单位体积干质量和总脂含量与营养盐浓度均呈显著的正相关;营养盐浓度为2f～4f时,上述各值与营养盐浓度则均呈显著的负相关。     

浸泡免疫迟钝爱德华氏菌疫苗诱导牙鲆黏液细胞的动态变化

为探明鱼类黏膜相关淋巴组织中黏液细胞对疫苗免疫的应答特性,本研究利用组织学和组织化学技术,研究了浸泡免疫灭活迟钝爱德华氏菌前后牙鲆皮肤、鳃、前肠、中肠和后肠中黏液细胞数量和特性的时序变化。苏木精-曙红(HE)、阿尔新蓝-过碘酸雪夫氏(AB-PAS)染色结果显示,免疫前皮肤主要分布含中性黏多糖的Ⅰ型黏液细胞以及含中性黏多糖和少量酸性黏多糖的Ⅲ型黏液细胞,鳃中可观察到Ⅰ、Ⅲ型以及含酸性黏多糖和少量中性黏多糖的Ⅳ型黏液细胞,前肠中主要分布Ⅰ型黏液细胞,中肠、后肠上皮中可观察到Ⅰ、Ⅲ、Ⅳ型和含酸性黏多糖的Ⅱ型黏液细胞。免疫后,牙鲆黏膜免疫相关淋巴组织中黏液细胞总量随时间呈现先增多后减少趋势,后肠在第5天达到峰值,其他于第3天达到峰值;免疫后各组织中Ⅰ型黏液细胞数量减少,含酸性黏多糖成分的Ⅱ、Ⅲ及Ⅳ型黏液细胞数量显著增多,表明疫苗免疫诱导黏液细胞成分由中性黏多糖向酸性黏多糖转变。p H 2.5和p H 1.0条件下AB染色结果显示,免疫后黏膜相关淋巴组织中酸性黏液细胞数量增多,且多数为硫酸化酸性黏液细胞。本研究结果为鱼类黏液的免疫防御功能及黏液细胞在鱼类黏膜免疫中的作用提供了理论依据。     

条石鲷消化道的形态学和组织学

采用解剖和光镜技术研究条石鲷消化道的形态学和组织学。条石鲷消化道包括具有发达颌齿的口咽腔，食道，胃，小肠和直肠。食道上皮组织可分为两个区域－头部和尾部，头部区域由扁平上皮层构成，尾部区域的上皮组织由单层柱状上皮细胞所构成，上皮含有大量 杯状细胞和黏液分泌细胞.胃呈V形，其粘膜上皮由单层柱状上皮组成，贲门部和胃体部上皮下有发达的胃腺组织。小肠上皮为具微绒毛的单层柱状上皮，肠道粘膜固有层中有管状肠腺存在；直肠上皮为单层柱状上皮，缺乏粘膜肌。小肠和直肠上皮中均分布有较多的杯状细胞，肠道系数约为0.78。在整个消化道中发现有四种杯状细胞。本文研究了条石鲷消化道的显微结构，并探讨了其消化道的组织学和解剖学特征与其杂食性的适应。     

Intensification of redclaw crayfish Cherax quadricarinatus culture: II. Growout in a separate cell system

In the process of exploring ways to intensify crayfish culture, a growout system of individual cages (cells) was designed to determine the effects of gender and cell size on the growth of the red claw crayfish Cherax quadricarinatus. Cells of three different diameters—large (25 cm), medium (20 cm) and small (16 cm)—were used. When crayfish were stocked at a mean weight of approximately 10 g, growth rate of males was significantly higher than that of females. The growth rate of the males in the large cells was 0.31±0.14 g/day, while that of the females was 0.18±0.09 g/day. The size of the cell had significant influence on the weight of males. Male crayfish in the large and medium cells grew better than those in the small cells. When males were stocked at a higher mean weight (about 23 g), their mean weight after 206 days was higher in the large cells (69.28±15.72 g) than in the small cells (58.11±12.66 g), suggesting that the growth of large males was also affected by cell size. Regardless of cell size, male animals of this species grew faster than females under conditions of individual cells. This intensive culture method appears to present a powerful improvement in yields, by as much as two orders of magnitude, in comparison with communal cultures.     

Differentiation and development of Leydig cell, and induction of spermatogenesis during testicular differentiation in the Japanese eel, Anguilla japonica

The initial appearance and the development of Leydig cells (LCs), the sites of steroid hormone production in the testis, were investigated ultrastructurally during testicular differentiation in the Japanese eel, Anguilla japonica. In addition, the effects of a single injection of human chorionic gonadotropin (HCG; 5 IU g body weight^-1) on histological changes of the testes and serum 11-ketotestosterone (11-KT) were examined at various stages (15–18, 20–23, 26–29, 32–35, 38–41 and 46–50 cm body length (BL)) of testicular differentiation. Testicular differentiation was morphologically characterized by the development of loose connective tissue on the medial side in animals 18–29 cm in BL. Ultrastructurally, LCs were first identified in the loose connective tissue of the testis of the 23 cm fish. In the testes of fish over 32 cm, clusters of LCs were distributed throughout the interstitial region accompanying the increase in number of spermatogonia. In fish larger than 32 cm, spermatogenesis was induced by administration of HCG; serum 11-KT levels were also raised. On the other hand, there was no effect on spermatogenesis or serum 11-KT levels in fish less than 29 cm, or in the controls. These result suggests that morphological differentiation of LCs occurs in testis of the 23 cm eel, and subsequently, the testes of eels of BL more than 32 cm acquire the capability to produce steroid hormones.     

胚胎干细胞的研究进展及应用前景

干细胞(Stem Cell)是一类具有分化潜能和自我复制的早期未分化细胞。胚胎干细胞(Embryonic stem cells,ES细胞)是一种早期胚胎内细胞团(inner cell mass,ICM)或原始生殖细胞(primordial germ cell,PGC)经体外分化抑制培养,分离和克隆得到的具有发育全能性的高度未分化细胞。本文综述了胚胎干细胞的形态学、生长特性、免疫学鉴定方法,ES细胞抑制分化和诱导分化的机理以及饲养层、血清和细胞因子等影响胚胎干细胞分离克隆的因素,并进一步阐述了胚胎干细胞的应用前景以及存在的问题。     

Effects of salinity on the growth and lipid composition of Atlantic salmon (Salmo salar) and turbot (Scophthalmus maximus) cells in culture

The direct effects of osmotic pressure (salinity) on growth performance and lipid composition were investigated in fish cells in culture. Cell lines from a relatively stenohaline marine species, turbot (Scophthalmus maximus) (TF) and an anadromous species, Atlantic salmon (AS) were cultured in media supplemented with NaCl to produce osmotic pressures varying from 300 to 500 mOsm kg⁻¹. The growth rates of the two cell lines were affected in a similar manner by the salinity of the media with the rank order for both peak cell numbers and growth rates up to the day of peak cell number being 300 > 350 > 400 > 450 > 500 mOsm kg⁻¹. Cell death occurred in both cell lines in older cultures at all salinities with the greatest loss of viable cells in media of 300 and 350 kg⁻¹. However, there were quantitative and qualitative differences between the cell lines in their lipid metabolism in response to the salinity of the media. The lipid content expressed per cell showed a positive correlation between lipid per cell and salinity in TF cells, but this was less apparent in AS cells. The percentage of total polar lipid classes increased with increasing salinity in TF cells due mainly to graded increases in the percentages of choline phospholipids. In contrast, there were no significant differences in the proportions of polar and neutral lipid classes with salinity in AS cells. The only significant effect of salinity in AS cells was a decreased proportion of dimethylacetals in total lipid at the highest salinity. The same significant effect of salinity on dimethylacetal content of total lipid was observed in TF cells. However, in addition there was a graded decrease in the percentage of 18:2n-9 in TF cell total lipid with increasing salinity. This was accompanied by increased percentages of total n-3 and n-6 PUFA with higher proportions of both groups of PUFA at 450 and 500 compared with 300 mOsm kg⁻¹. The results show that environmental salinity, in the absence of hormonal or other physiological stimuli, has direct effects on the growth and lipid metabolism of fish cells and that these effects differ in cells from different fish species.     

中药替代PHA体内注射获取大量鱼类肾细胞中期分裂相

报道以党参、当归和黄芪煎汁液替代PHA体内注射,促使鱼类肾淋巴细胞转化、分裂、增殖,以获取大量中期分裂相,制备染色体标本的方法。作者对三批30条胡子鲶的实验结果表明:党参、当归和黄芪煎汁液体内注射同样具有刺激肾细胞有丝分裂的作用.     

紫外线诱变建立草鱼抗出血病病原病毒的AHZC88细胞株

通过UV对草鱼出血病病原病毒敏感的草鱼ZC 7901细胞株反覆诱变,获得了对出血病病原病毒具有抗性的AHZC 88细胞株。经生物学特性测定,AHZC 88细胞的染色体2n=48,温度适应范围4°～38℃,最适生长温度27℃,分裂指数在36小时时达最高值。经病原病毒的人工侵染等试验表明,AHZC 88细胞不受草鱼出血病病毒感染。在电镜切片观察中,细胞内不见病毒颗粒。LDH同工酶分析,比敏感细胞少1条酶带。