Infrared Spectroscopic Study of Loach Liver under Cadmium Stress

[ Objective ] In order to study the influence of cadmium stress on loach liver. [ Method ] FTIR-NEXUSTM Fourier transform infrared spectrometer（FTIR） was used to scan liver sample with wavelength from 1 800 -400 cm^-1. The collected infrared spectrum was conducted deconvolution and curve fitting treatment to analyze changing trend of relevant macromolecular compounds in loach liver tissue under Cd^2＋ stress. [ Result ] The structures of protein and nucleic acid as well as their synthesis pathways changed significantly. [ Conclusion]FTIR technique possessed broad application value in studying animal resistance and environment monitoring.

Research on Embryonic Development of Loach

[Objective] Aim to know the whole process of embryonic development of loach. [Method] DOM + LHRH-A2 was used to induce spawning of loach,then after fertilization,the embryos were cultured into freshwater water with temperature from 24 to 26 ℃ and pH from 7.0 to 7.5. The embryonic development of loach was observed and 27 concrete morphological characteristics and development time of loach from fertilized egg to newly hatched larval period were described in detail. [Result] The embryonic development of loach could be divided into cleavage stage,blastocyst stage,gastrula stage,neurula stage and organogenesis stage. The loach embryo from fertilized egg to out membrane period was 30 h 45 min in fresh water from 24 to 26 ℃ and pH from 7.0 to 7.5. [Conclusion] It provided important reference for studying artificial propagation and genetic breeding of loach.

Ecotoxicological effects of mixed pollutants resulted from e-wastes recycling and bioaccumulation of polybrominated diphenyl ethers in Chinese loach(Misgurnus anguillicaudatus)

To understand potential ecotoxicological effects of electrical and electronic equipment waste （e-waste） recycling and polybrominated diphenyl ethers （PBDEs） bioaccumulation in loaches, a semi-field experiment using Chinese loach （Misgurnus anguiUicaudatus） as experimental fish was performed. Larval loaches were kept in net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site （27%, 19/70） and from reference site （70%, 49/70）. Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers （PBDEs）, the main pollutants in e-waste, in loaches was also studied, the mean concentration of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L （dissolved phase）. BDE 209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE 209 （less than 0.01% of total PBDEs） and high concentration of BDE47 （up to 39.34% of total PBDEs） were detected in loaches.

Schistura porthos Kottelat,2000,a new record of nemacheilid loach for China

A nemacheilid loach not recorded for China so far has been collected during a survey of the Nanxinghe River,Luosuojiang River subbasin,Mekong basin.The specimens could be identified as Schistura porthos Kottelat,2000.The occurrence in the Luosuojiang River subbasin is a distributional range extension.

Distribution of endocrine-disrupting PCBs in hard roes of loaches and their potential ecological effects in Weishanhu Lake,China

Preliminary study is carried out on the endocrine-disrupting organic chemicals of polychlorinated biphenyls(PCBs: PCB-28, 60, 104, 153, 190) in hard roes of loaches( Misgurnus anguillicaudatas ) in Weishanhu Lake, China. Results showed that the hard roes of loaches collected from the areas near the influx(such as Pengkou T-PCB=0.243 μg/g) or efflux(such as Hanzhuang T-PCB=0.221 μg/g) are characterized by higher PCB contents, about 4 times that from the central lake(T-PCB=0.066 μg/g), suggesting great difference between their pollutions. The PCB distributions indicated that PCB congeners with more chlorine are more easily accumulated in roes of loaches. The microscopic characteristics reveal that the PCB contents at present cannot lead the roes of loaches to be abnormal. However, the roes with higher PCBs in Pengkou and Hanzhuang are obviously bigger than those with lower PCBs(T-PCBs≤0.176 μg/g) in other localities. It is suggested that PCBs have a stronger estrogenic activity on the roes of loaches, and the phenomenon is likely premonitory for the abnormal development of the hard roes.

A Novel Oligosaccharide from the Mucus of the Loach

A novel oligosaccharide was isolated and purified from the mucus of the loach, Misgurnus anguillicaudatus. It was identified by several qualitative tests and characterized by elementary analysis, UV and IR spectrum. Its average molecular weight (Mw=1539.4) was determined by gel permeation chromatography. The major structural monomers of Misgurnus anguillicaudatus oligosaccharide were identified to be D-galactose and L-fucose by paper chromatography and gas chromatography.

Development of Inter-Family Nuclear Transplant Embryos by Transplanting the Nuclei from the Loach Blastulae into the Non-Enucleated Zebrafish Eggs

The developmental fate of the pronuclei in recombined embryos obtained by transplanting the donor nuclei into the non-enucleated eggs remains controversial in the case of fish. In the present study, the nuclei from the loach blastulae were transplanted into non-enucleated zebrafish eggs, the resulting 9 inter-family nuclear transplant embryos developed to larval stages. Although the development timing of the nuclear transplants resembled that of zebrafish, chromosome examination revealed that most of the recombined embryos were diploids with karyotype characteristic of loach, which was also proved by RAPD analysis. Moreover, 3 out of the 9 larval fish formed barb rudiments specific to loach. It was therefore concluded that the nuclear transplant larval fish were inter-family nucleo-cytoplasmic hybrids; and that only the donor nuclei were involved in the development of the nuclear transplant embryos, while the pronuclei in the non-enucleated eggs were likely automatically eliminated during the development.

Study on the Toxicity of Acetochlor to Loaches

[Objectives] This study was conducted to investigate the toxic effect of acetochlor in loaches. [Methods]Loaches were put into the acetochlor solution with concentrations of 0,0. 062 5,0. 125,0. 25,0. 5 and 1 μl/L,respectively. The effects on dismutase( SOD),peroxidase( POD),catalase( CAT) and glutathione( GSH) activity and malondialdehyde( MDA) content in the liver of loaches were analyzed after 12,24,48 and 72 h of exposure. [Results] The activity of SOD,POD,CAT and GSH increased with the stress time and concentration,reached their maximums at 48 h after acetochlor treatment,and then decreased.However,MDA content increased with the stress time and concentration. [Conclusions] Acetochlor had obvious oxidative stress on loaches,and the activity of SOD,POD,CAT and GSH showed an obvious induction-inhibition effect with the increase of acetochlor concentration and the extension of stress time.

Effect of New Fly Maggot Protein Feed on mRNA Expression of TOR Signaling Pathway-related Genes in Loaches (Misgurnus anguillicaudatus)

[Objectives] This study was conducted to explore the effects of new fly maggot protein feed on the mRNA expression of genes related to the TOR signaling pathway in loaches(Misgurnus anguillicaudatus). [Methods] Two kinds of test feed with equal nitrogen and energy were prepared by replacing 60% of the fish meal in the control group with the new fly maggot protein feed, i.e., Diet1(control group) and Diet2(60% fish meal replacement group). The feeding experiment was carried out in an indoor circulating water system, and the breeding period was 60 d. [Results] For the livers, the mRNA levels of TOR and 4EBP1 in the Diet2 group were significantly higher than those in the Diet1 group(P<0.05), while the expression of 4 EBP2 was lower than in the Diet1 group(P<0.05);and as to the muscles, the mRNA levels of TOR and 4EBP1 in the Diet2 group were significantly lower than those in the Diet1 group(P<0.05), while there was no significant change in the mRNA level of 4EBP2 between the two groups. [Conclusions] The replacement of fish meal by fly maggot cultures affected the mRNA expression of TOR, 4EBP1 and 4EBP2 in loach livers and muscles.

Electrofusion between Blastula Cells and Unfertilized Egg in Loach (Paramisgurnus dabryanus)

Electrofusion between blastula cells and unfertilized eggs in loach were investigated usingdielectrophoretic field where, under alternating sinusoidal electric field, blastula cells formed beads-like chain in close contact with the unfertilized egg and cell fusion occurred between eggs and thecells in tight contact with them. The nuclei ofblastula cells were brought into the cytoplasm of therecipient eggs, where they promoted the development of the fused eggs just like the zygote nuclei.But the development of the fused eggs was different from that of zygotes. Several nuclei might enterone and the same egg simultaneously and all of them could undergo division, resulting in severalblastomere after the first cleavage of the recipient egg. Before blastula stage, the embryo developingfrom the fused egg showcd irregular shape, but it was soon regulated and developed to a normalblastula which often continued its development into a normal individual. Cell/egg electrofusion cameto its highest fosion rate (80%) 8nd hatching rate (20%), with cell density at 1×10~3 cells/ml, Ca^(++)concentration at 10 mM, mannitol at 0.2 M and when the blastula cells were digested with 100μg/ml pronase E for 6-10 min at 20℃. The mechanism underlying development of electrofused eggsis discussed. As the result indicates, electrofusion might prove to be a promising biotechnology justas nuclear transplantation.

泥鳅扰动对稻田土壤孔隙水中砷的影响

为探究不同养殖密度(低密度、中密度、高密度)泥鳅扰动对土壤孔隙水中砷(As)含量的影响,采集湖南浏阳稻田表层土,以泥鳅为扰动生物,对泥鳅扰动土壤孔隙水中As含量变化进行研究,为进一步开展土壤-水环境中As循环研究提供基础数据。结果表明:泥鳅扰动后,土壤pH随时间先升高后降低,扩散层变宽,并逐渐向深层土壤扩散,泥鳅组土壤pH表现为:中密度组>低密度组>高密度组,低密度组和中密度组土壤溶解氧(DO)显著高于对照组和高密度组(P<0.05),中密度组土壤DO略高于低密度组,推测中密度组的扰动能力较其他密度组强;土壤-水界面pH和DO梯度变化明显,低密度组和中密度组土壤-水界面DO变化梯度较高密度组大,分层现象明显,各处理土壤体系DO表现为:土壤上覆水>土壤-水界面>土壤;泥鳅扰动促进了As由土壤向土壤上覆水迁移释放,显著增加了土壤上覆水As含量,其中低密度组促进效果较中密度组和高密度组显著;各处理土壤孔隙水As含量随时间逐渐减小(淹水期除外),从土壤深处向土壤-水界面迁移,总体呈现为土壤表层小于深层,泥鳅扰动能显著减少土壤孔隙水As含量,尤其对低密度组和中密度组土壤孔隙水As含量减少具有一定促进作用,同时也促进了土壤中As向土壤-水界面迁移释放;第7天时,泥鳅组土壤孔隙水As含量变化最显著,贯穿于整个土壤深度,低密度组As含量显著小于中密度组和高密度组,说明低密度组促进效果较中密度组和高密度组显著,这与土壤上覆水结果一致。研究表明,泥鳅扰动显著减少了土壤孔隙水As含量,其中低密度组和中密度组对不同深度土壤孔隙水As含量减少具有一定的促进作用,同时也促进了土壤中As向土壤-水界面迁移释放。

台湾泥鳅精子超低温冷冻保存技术研究

为建立台湾泥鳅精子超低温冷冻保存方法,采用显微镜观察精子活率,流式细胞术检测质膜完整性,研究4种稀释液[Hank′s平衡盐溶液(HBSS)、D-15、D-17、鱼用任氏液],5种抗冻剂(甲醇、乙二醇、丙二醇、二甲基亚砜、N,N-二甲基甲酰胺)在4个体积分数(2.5%、5.0%、7.5%、10.0%),不同平衡时间、熏蒸高度和时间、解冻温度和时间对台湾泥鳅精子超低温冷冻保存的影响。试验结果显示:以Hank′s平衡盐溶液为稀释液的精子活率最高,为(45.28±5.75)%;以5%甲醇作为抗冻剂的台湾泥鳅精子活率和质膜完整比例最高,分别为(51.25±5.03)%和(81.70±2.35)%;最佳平衡时间为30 min,最佳熏蒸高度和时间为9 cm和10 min,最后将冻精在37℃水浴锅中解冻10 s的解冻效果更佳。用冷冻复苏的台湾泥鳅精子进行人工授精,受精率达(68.94±6.22)%。综上,用Hank′s平衡盐溶液稀释台湾泥鳅鲜精,与甲醇1∶1混合至终体积分数为5%,放于4℃平衡30 min,而后装入麦管,在液氮面上方9 cm处熏蒸10 min后投入液氮保存可作为台湾泥鳅精子超低温冷冻的保存方法,解冻时在37℃水浴锅中解冻10 s,可获得更好的解冻效果。

杀菌剂甲基托布津和多菌灵对泥鳅的急性毒性及肝脏酶活性的影响

为了解甲基托布津(Methyltobuzine,TM)和多菌灵(Carbendazim,BCM)对水生动物的毒性效应,在水温(25±2)℃下,将平均体长(6.3±0.7)cm和平均质量(2.4±0.5)g的6月龄泥鳅(Misgurnus anguillicaudatus)置于65 mg·L^(-1)、85 mg·L^(-1)、112 mg·L^(-1)、146 mg·L^(-1)、191 mg·L^(-1)TM和26 mg·L^(-1)、34 mg·L^(-1)、45 mg·L^(-1)、58 mg·L^(-1)、76mg·L^(-1)BCM下,采用半静水实验法,研究TM和BCM的24 h、48 h、72 h、96 h的半致死浓度(LC50)和24 h安全浓度(SC);并在0.05 mg·L^(-1)、0.50 mg·L^(-1)、5.00 mg·L^(-1)TM和0.02 mg·L^(-1)、0.10 mg·L^(-1)、0.50 mg·L^(-1)、2.50 mg·L^(-1)BCM中胁迫7 d、14 d、21 d、28 d,检测泥鳅肝脏过氧化物酶(POD)、谷丙转氨酶(GPT)、谷草转氨酶(GOT)活性变化。结果表明,TM对泥鳅的24 h、48 h、72 h、96 h LC50分别为35.48 mg·L^(-1)、26.98 mg·L^(-1)、17.25 mg·L^(-1)和10.03 mg·L^(-1),24 h SC为6.16 mg·L^(-1);BCM对泥鳅的24 h、48 h、72 h、96 h LC50分别为23.53 mg·L^(-1)、17.66 mg·L^(-1)、6.54 mg·L^(-1)和3.58 mg·L^(-1),24 h SC为3.98 mg·L^(-1);TM和BCM胁迫下POD、GOT、GPT活性随浓度升高呈现先上升后下降的趋势,随着胁迫时间延长各参数的活性呈下调趋势。BCM处理组较TM处理组变化趋势更显著。综上所述,TM对6月龄泥鳅具有低毒性作用,BCM对6月龄泥鳅则具有中等毒性作用;一定剂量TM和BCM长期胁迫对泥鳅造成严重影响,对POD、GPT、GOT活性具有明显抑制作用,随胁迫时间延长抑制加剧,其中BCM较TM抑制作用更强。

低酯果胶和玉米淀粉对泥鳅肌原纤维蛋白凝胶特性的影响

该研究旨在探讨外源添加物对肌原纤维蛋白凝胶特性的影响,以改善淡水鱼糜的性能。将泥鳅肌原纤维蛋白与不同含量(0%~25%)的低酯果胶和玉米淀粉混合制备复合胶,采用质构仪、色差分析仪、扫描电子显微镜和红外光谱仪对其性能进行研究。结果表明,加入低酯果胶后,凝胶硬度、强度和持水力显著升高,蒸煮损失显著降低;添加玉米淀粉后,凝胶强度和持水力显著提高。同时,低酯果胶添加量和玉米淀粉添加量分别为25%和10%时,凝胶网络结构最紧凑有序。红外结果显示,添加低酯果胶和玉米淀粉能促进热凝胶过程中β-折叠结构的形成。该研究结果可为泥鳅鱼糜的加工提供理论指导。

杂交3倍体泥鳅鳍细胞系染色体组构成研究

通过天然4倍体(4n=100)和2倍体(2n=50)泥鳅杂交创制不同子代杂交组合(4n♀×2n♂、2n♀×4n♂)。以传代20次的杂交3倍体泥鳅鳍细胞系为材料,采用常规冷滴片法制备染色体标本,通过吉姆萨染色确定数目及核型;通过银染法及CMA_3/DA/DAPI三重荧光染色技术对其进行带型分析。结果显示:正反交3倍体鳍细胞系的染色体分裂相数目为3n=75,核型公式15m+6sm+54t,NF=96;正反交3倍体泥鳅鳍细胞系的染色体分裂相中显示有3个银染点,均位于第1组中部着丝粒染色体(M1)短臂的端部区域;正反交3倍体泥鳅鳍细胞的染色体中期分裂相中显示有3个CMA_3荧光信号点,均位于M1区域。研究表明:杂交3倍体泥鳅鳍细胞经细胞培养传代20次后的染色体组成未发生改变,其染色体数目、核型和带型与3倍体泥鳅其他体细胞结果一致。

Catching Loaches

People would like to say South China is a region which can Bring forward men of

Effects of cadmium,17 β-estradiol and their interaction in the male Chinese loach (Misgurnus anguillicaudatus)

To assess the interaction effect between cadmium (Cd) and 17-estradiol (E2),male Chinese loaches (Misgurnus anguillicaudatus) were exposed to E2 (1 g/L) and Cd (50 or 500 g/L) alone and in combination using a semi-static waterborne exposure system.The effects of E2 on the accumulation and distribution of Cd,as well as the effects of Cd on vitellogenin (Vtg) synthesis induced by E2,were investigated.Cd mainly accumulated in the kidneys,liver,intestines,and gills,with little amounts in muscles,bones,and gonads.Co-exposure with E2 did not change the main targets for Cd.E2 could induce Vtg synthesis in male Chinese loaches,and co-exposure with 50 or 500 g/L Cd could inhibit the Vtg induced by 1 g/L E2.Compared with the results reported in the literature,it can be concluded that factors such as fish species,Cd dosage,and manner of exposure might make contributions to the interaction between Cd and E2.Our results also suggested that male Chinese loaches are susceptible to Cd,and can be recommended as a potential sentinel species to study the ecotoxicology of heavy metals.

Vitellogenic responses of male Chinese loach (Misgurnus anguillicaudatus) exposed to the individual or binary mixtures of 17β-estradiol and nonylphenol

Male Chinese loaches were exposed to 17β-estradiol (E2) and nonylphenol (NP) both singly and in combination for 42 days using semi-static waterborne exposure system. Plasma vitellogenin (Vtg) was chosen as determining endpoint. The results demonstrated that 0.5 μg/L E2 could induce the enhancement of Vtg contents in male Chinese loaches after exposure for 21 days, which showed a time-related increasing manner; NP was also estrogenic to male Chinese loach, and the vitellogenic responses showed in a time-and dose-related manner, which was less potent than that of E2. The bi- nary mixtures of E2 and NP can significantly elicit the production of Vtg in male Chinese loaches, which was more potent than that of individual compounds, and Vtg induced in the binary mixture groups was higher than the summation of Vtg induced in the corresponding single-compound groups at the same concentration.

饲料中添加黄芪多糖对台湾泥鳅苗生长性能、器官指数及抗氧化能力的影响

文章旨在研究饲料中添加不同含量水平的黄芪多糖对台湾泥鳅苗生长性能、器官指数及抗氧化能力的影响。试验选取270尾健康的台湾泥鳅鱼苗,初始体长(6.23±0.78)cm,体重(2.51±0.08)g。鱼苗随机分为3组,每组3个重复,每个重复30尾。各组台湾泥鳅苗分别饲喂基础饵料+0、200、400 mg/kg黄芪多糖,试验为期62 d。结果表明:1)与0 mg/kg黄芪多糖组相比,200、400 mg/kg黄芪多糖组泥鳅的末重显著提高10.06%、37.74%(P<0.05),特定生长率显著升高15.53%、50.49%(P<0.05),增重率显著升高20.31%、80.81%(P<0.05)。2)3组泥鳅的肝体比、脏体比无显著差异(P>0.05)。3)与0 mg/kg黄芪多糖组相比,400 mg/kg黄芪多糖组总抗氧化能力显著提高(P<0.05),200 mg/kg黄芪多糖组总超氧化物歧化酶活性显著提高(P<0.05),200、400 mg/kg黄芪多糖组溶菌酶活性显著提高(P<0.05),丙二醛显著降低(P<0.05)。由此可见,在饲料中添加400 mg/kg黄芪多糖可提高台湾泥鳅苗的生长性能,改善抗氧化能力。

泥鳅黏液多糖的化学组成、理化性质及体外降糖活性

为对泥鳅的加工与流通副产物黏液进行开发利用,采用超声辅助的水提醇沉法,从大鳞副泥鳅黏液中提取一种泥鳅黏液多糖(PDMP)。采用紫外光谱、凝胶过滤色谱、高效液相色谱、傅里叶变换红外光谱、1H NMR和13 C NMR分析PDMP化学组成,采用X射线衍射、热重分析和扫描电镜研究PDMP的理化性质。结果表明,PDMP的总糖含量为(95.51±2.27)%,硫酸基含量为(23.41±0.87)%,不含糖醛酸,含有乙酰基。PDMP的分子质量为362928 u,由岩藻糖、半乳糖、甘露糖、葡萄糖和木糖组成,物质的量比为13.27∶5.68∶2.31∶2.23∶0.45。PDMP中含有(1→)-和(1→6)-的α-糖基和β-糖基的吡喃糖。PDMP热稳定较强,有一定的结晶性,表面具有均一密集的蜂窝状孔洞,内部具有大小不一的孔洞结构。体外降糖研究表明,PDMP对α-淀粉酶和α-葡萄糖苷酶抑制活性的IC50值分别为152μg/mL和550μg/mL。9 mg/mL的PDMP对α-淀粉酶和α-葡萄糖苷酶活性的抑制率分别达到65.02%和86.40%。本研究结果为PDMP在现代食品工业和医药领域的应用提供参考。