Helminth parasites of freshwater fishes from Cuatro Ciénegas,Coahuila, in the Chihuahuan Desert of Mexico: inventory and biogeographical implications

As part of an ongoing inventory of the helminth parasites of freshwater fishes in Mexico, 570 individual fish were collected between Apr 2008 and Oct 2011 in 26 localities along the Cuatro Ciénegas region in Coahuila State, northern Mexico. Seventeen species of hosts, mostly corresponding to Nearctic freshwater elements, were studied. A total of 8324 individual worms were collected during this survey, representing 25 species of helminths, of which 9 were digeneans, 3 monogeneans, 3 acanthocephalans, 9 nematodes and 1 cestode. Most of the records in this checklist represent new host or locality records. The information provided in this checklist may be helpful for our understanding of the biodiversity and historical biogeography of this host–parasite system, because in the Cuatro Ciénegas region occur a Nearctic freshwater fish fauna, along with Neotropical and endemic elements, and from a biogeographical point of view, this may represent a transitional area.     

无公害金鳟养殖技术

金鳟（Oneorhynchus），又称甘脂鱼或黑珍珠石斑，是日本从虹鳟的突变种选育出的金黄色品系，1996年引进我国后根据其体色特征命名为“金鳟”。金鳟肉质细嫩，味道鲜美，肉厚刺少，蛋白质含量丰富，人体必需氨基酸和必需脂肪酸含量高，营养价值极高，不含胆固醇且容易消化吸收。     

Helminths of seven species of lacertid lizards from southern Africa

Two hundred and forty five lacertid lizards representing seven species (Heliobolus lugubris, Ichnotropis squamulosa, Meroles anchietae, M. cuneirostris, M. suborbitalis, Pedioplanis lineoocellata, P. namaquensis) from southern Africa were examined for helminths. Adults of one species of cestode, Oochoristica ubelakeri, and four species of nematodes, Maxvachonia dimorpha, Parapharyngodon rotundatus, Spauligodon smithi, Thubunaea fitzsimonsi and metacestodes of a cyclophyllid cestode, the nematodes, Abbreviata sp. and an undetermined ascarid species, and an acanthocephalan species (as cystacanths) were found. Mean helminth species richness for adult helminths was 2.4 ± 1.3 S.D. (range = 1–4 per host species).     

Localization of the N-methyl-D-aspartate R1 Receptor in the Pituitary Gland of Immature Rainbow Trout (Oncorhynchus mykiss)

A study was conducted on the selective immunostaining of pituitary cells and pars nervosa of immature rainbow trout by antibody raised against the R1 subunit of the rat ionotropic N-methyl-D-aspartate (NMDA) receptor. In the pars distalis, the mammotrophs of the rostral pars distalis exhibited the most marked imunoreactivity, with the somatotrophs of the proximal pars distalis showing a consistently lower degree of immunoreactivity. No imunoreactivity was associated with the corticotrophs, thyrotrophs or gonadotrophs. In the pars intermedia, the melanotrophs showed no evidence of immunoreactivity, whereas the putative somatomammotrophs exhibited a wide inter-animal range of immunoreactivity. Some imunostaining was also evident in the anterior and posterior part of the pars nervosa, at the interface of the pars distalis or pars intermedia with the pars nervosa.     

Flow Cytometric Analysis of Mitogen‐Induced Activation of Rainbow Trout (Oncorhynchus mykiss) Peripheral Blood Leucocytes

Proliferation of rainbow trout peripheral blood leucocytes in vitro is usually assessed by measuring incorporated tritiated thymidine. In this report we monitored the in vitro proliferative response to the mitogen Concanavalin A (Con A) by means of flow cytometry (FCM) and ³H‐thymidine incorporation. When analysed by FCM, blood leucocytes displayed two main cell populations with distinct forward and side scatter (FSC/SSC) characteristics: lymphocytes with low FSC/SSC values and non‐lymphoid leucocytes (NLL) with increased FSC/SSC values. The nature of these cell types were confirmed by microscopy. Interestingly, the FSC/SSC pattern of lymphocytes remained unchanged after in vitro stimulation with Con A, whereas cells from the NLL population showed a marked shift towards increased FSC values. In stimulated cultures, the increase of FSC values of the NLL population significantly correlated with contemporarily measured ³H‐thymidine incorporation (r=0.7, P < 0.001). The mitogenic response of blood leucocytes originating from different individual fish varied over wide ranges. It was found to be related to the numbers of NLL present in the leucocyte sample. The present results show that qualitative and quantitative FCM analysis of morphological parameters (FSC/SSC) of blood leucocytes makes it possible to discriminate between leucocyte populations of the rainbow trout and to monitor cell proliferation experiments.     

虹鳟酪氨酸酶基因的生物信息学分析及其在不同发育阶段和组织中的表达分析

酪氨酸酶（tyrosinase,Tyr）基因在调控动物色素合成的过程中发挥关键作用。为了解tyr基因与虹鳟（Oncorhynchus mykiss）体色变异的关系,本研究对虹鳟tyr-1和tyr-2基因进行了蛋白序列分析,并利用实时荧光定量PCR检测两种基因在野生型虹鳟（虹鳟）和黄色突变型虹鳟（金鳟）体色发生的19个不同时期和成鱼13种不同组织中的表达差异。蛋白序列分析结果表明,Tyr-1和Tyr-2都是亲水性蛋白,且蛋白结构主要是无规则卷曲和α-螺旋;实时荧光定量PCR结果显示,tyr-1基因在胚胎各时期均有表达,tyr-1基因表达量在虹鳟受精期最高,桑椹期次之,且显著高于其他时期（P<0.05）;tyr-1基因表达量在金鳟16-细胞期最高,且显著高于其他时期（P<0.05）;tyr-2基因分别从虹鳟囊胚期和金鳟原肠期开始表达,表达量均在心跳期达到最高且显著高于其他时期（P<0.05）。出膜后,tyr-1、tyr-2基因分别在虹鳟5日龄和金鳟3月龄表达量最高。在胚胎各时期中,tyr-1、tyr-2基因在虹鳟中表达量普遍高于金鳟,出膜后普遍低于金鳟。在各组织中,tyr-1基因在皮肤、眼睛、肾脏、肝脏等组织中有较高表达,tyr-2基因主要在皮肤、眼睛中有较高表达,在其他组织中表达量较低。以上结果表明,tyr-1和tyr-2基因与虹鳟体色变异具有一定的相关性,为深入阐明虹鳟体色变异机制和体色遗传改良奠定了理论基础。     

壳寡糖对虹鳟生长性能、血清生化指标及非特异性免疫功能的影响

本文旨在研究壳寡糖对虹鳟生长性能、血清生化指标及非特异性免疫功能的影响。选用体重约为 ６０ｇ的虹鳟 ４８０尾,随机分为 ４组（每组 ４个重复,每个重复 ３０尾）,分别饲喂在基础饲料中添加 ０、１００、２００和 ４００ｍｇ／ｋｇ壳寡糖的试验饲料。试验期为 ４９ｄ。结果表明：１）与对照组相比,１００、２００和 ４００ｍｇ／ｋｇ壳寡糖组的特定生长率分别提高了 ５．６０％（Ｐ＜０．０５）、１５．８９％（Ｐ＜０．０５）和１８．６９％（Ｐ＜０．０５）,增重率分别提高了７．５３％（Ｐ＜０．０５）、２１．２１％（Ｐ＜０．０５）和 ２６．０２％（Ｐ＜０．０５）,蛋白质效率分别提高了 ０．６０％（Ｐ＞０．０５）、７．０２％（Ｐ＞０．０５）和９．７９％（Ｐ＜０．０５）,饲料系数分别降低了 ０．６０％（Ｐ＞０．０５）、６．５５％（Ｐ＞０．０５）和 ８．９３％（Ｐ＜０．０５）;２）饲料中添加壳寡糖提高了虹鳟血清总蛋白、白蛋白、球蛋白含量（Ｐ＞０．０５）,降低了血清甘油三酯、胆固醇、葡萄糖含量以及谷丙转氨酶和谷草转氨酶活性（Ｐ＞０．０５）;３）饲料中添加２００和 ４００ｍｇ／ｋｇ壳寡糖可显著或极显著提高虹鳟的白细胞吞噬百分率（Ｐ＜０．０５）、吞噬指数（Ｐ＜０．０５）,血清杀菌百分率（Ｐ＜０．０１）以及血清、肝脏和鳃中溶菌酶活性（Ｐ＜０．０５）;４）虹鳟全鱼水分、粗蛋白质、粗脂肪、灰分含量在各组间差异不显著（Ｐ＞０．０５）。由此得出,在本试验条件下,饲料中添加壳寡糖可提高虹鳟的生长性能和非特异性免疫功能,建议添加量为２００ｍｇ／ｋｇ。     

Effects of Chito-Oligosaccharides on Growth Performance,Serum Biochemical Indices and Non-Specific Immunity Function of Rainbow Trout (Oncorhynchus mykiss)

本文旨在研究壳寡糖对虹鳟生长性能、血清生化指标及非特异性免疫功能的影响.选用体重约为60 g的虹鳟480尾,随机分为4组(每组4个重复,每个重复30尾),分别饲喂在基础饲料中添加0、100、200和400 mg/kg壳寡糖的试验饲料.试验期为49 d.结果表明:1)与对照组相比,100、200和400 mg/kg壳寡糖组的特定生长率分别提高了5.60％ (P ＜0.05)、15.89％ (P ＜0.05)和18.69％(P＜0.05),增重率分别提高了7.53％ (P ＜0.05)、21.21％ (P＜0.05)和26.02％ (P ＜0.05),蛋白质效率分别提高了0.60％ (P ＞0.05)、7.02％ (P ＞0.05)和9.79％ (P ＜0.05),饲料系数分别降低了0.60％(P＞0.05)、6.55％ (P ＞0.05)和8.93％(P＜0.05);2)饲料中添加壳寡糖提高了虹鳟血清总蛋白、白蛋白、球蛋白含量(P＞0.05),降低了血清甘油三酯、胆固醇、葡萄糖含量以及谷丙转氨酶和谷草转氨酶活性(P＞0.05);3)饲料中添加200和400 mg/kg壳寡糖可显著或极显著提高虹鳟的白细胞吞噬百分率(P＜0.05)、吞噬指数(P＜0.05),血清杀菌百分率(P＜0.01)以及血清、肝脏和鳃中溶菌酶活性(P＜0.05);4)虹鳟全鱼水分、粗蛋白质、粗脂肪、灰分含量在各组间差异不显著(P＞0.05).由此得出,在本试验条件下,饲料中添加壳寡糖可提高虹鳟的生长性能和非特异性免疫功能,建议添加量为200 mg/kg.     

茶多酚对虹鳟生长性能、生化指标和非特异性免疫指标的影响

本试验研究了不同水平茶多酚对虹鳟生长、肉质、血浆生化指标和免疫指标的影响.选取2日龄初始体重(152.23±4.90)g的虹鳟560尾,随机分为6组,分别饲喂添加0、25、50、100、500、1 000 mg/kg茶多酚饲料,每组3个重复,每个重复30尾鱼,试验进行8周.结果显示:与对照组相比,添加不同水平的茶多酚对虹鳟增重率、特定生长率和饵料系数未产生显著的影响(P>0.05),但显著提高肝体比和脏体比(P<0.05).除茶多酚25 mg/kg组外其它试验组鱼体水分含量显著降低(P<0.05),茶多酚1 000 mg/kg组显著降低鱼体粗脂肪含量(P<0.05),茶多酚25 mg/kg组显著升高鱼体粗蛋白质含量(P<0.05).随着茶多酚添加量的增加,谷草转氨酶(GOT)逐渐下降,除25 mg/kg组外各试验组均显著低于对照组(P<0.05);谷丙转氨酶(GPT)、总胆固醇(CHO)、低密度脂蛋白(LDL)和高密度脂蛋白(HDL)差异不显著(P>0.05).随着茶多酚从25 mg/kg提高到100 mg/kg,肝脏和肌肉中的SOD活性升高,茶多酚25 mg/kg组肌肉SOD和50 mg/kg组肝脏SOD显著升高(P<0.05);肌肉和血浆中MDA下降,25、100 mg/kg组肌肉和50、100 mg/kg组血浆MDA显著(P<0.05或P<0.01)下降;茶多酚50 mg/kg组肝脏、鳃中AKP、ACP活性与对照组相比显著升高(P<0.05),但500和1 000 mg/kg组却未表现出明显的作用.以上结果表明:添加50～100 mg/kg茶多酚可改善虹鳟非特异性免疫和肌肉品质;但茶多酚超过500 mg/kg对虹鳟未产生有益作用.     

Leptin mRNA and Protein Immunoreactivity in Adipose Tissue and Liver of Rainbow Trout (Oncorhynchus mykiss) and Immunohistochemical Localization in Liver

Leptin is an important modulator of energy balance and metabolism in mammals, but for evolutionary older vertebrates like fish, the first reports on leptin expression were only recently characterized and the functional role scarcely. In this study, we demonstrated leptin immunoreactivity in liver tissue of rainbow trout (Oncorhynchus mykiss) by immunohistochemistry using three different polyclonal antibodies against mammalian leptin. Immunoreactivity was observed in hepatocytes and also in parts of the biliary system. Using Western blot, we detected an immunoreactive band of about 16 kDa in serum and visceral adipose tissue (AT) of rainbow trout. The presence of leptin in fish AT has been doubted in other studies. Besides the immunoreactivity, leptin mRNA was detected in trout AT albeit not in all animals sampled. Our observations add further evidence to the concept of AT being a source of leptin in trouts. Moreover, the cellular localization of leptin immunoreactivity in liver opens up new vistas for understanding the functional role of leptin in teleosts.     

Effects of Ferrous Fumarate on Growth Performance, Blood Biochemical Parameters and Trace Element Contents of Juvenile Rainbow Trout ( Oncorhynchus mykiss )

本试验旨在研究富马酸亚铁对虹鳟幼鱼生长性能、血液生化指标及微量元素含量的影响.选择初始体重为(89.2±0.2)g的虹鳟幼鱼360尾,随机分成6组,每组3个重复,每个重复20尾鱼,分别饲喂添加富马酸亚铁0、20、40、80、160、480 mg/kg(以铁计)的试验饲料,各组分别为D0、D20、D40、D80、D160和D480组,D0组为对照组.各组铁实测含量分别为62.6、79.5、99.6、139.3、215.2、538.4mg/kg,试验期60 d.结果表明:1)饲料中不同铁水平对虹鳟幼鱼生长性能无显著影响(P＞0.05).2)血红蛋白含量和红细胞数量呈现先上升后平稳的趋势;各组血细胞比容无显著差异(P＞0.05).3)各组全鱼、脊椎骨和肌肉铁含量随着饲料中铁水平的升高而升高,肝脏铁含量呈现先上升后平稳的趋势;各组全鱼锌含量无显著差异(P＞0.05),D0组脊椎骨和肌肉锌含量显著高于其他各组(P＜0.05),D0和D20组肝脏锌含量显著高于其他各组(P＜0.05);全鱼铜含量随饲料铁含量的升高而升高,各组脊椎骨铜含量无显著差异(P＞0.05),D0组肌肉铜含量显著低于其他各组(P＜0.05).4) D0组血清溶菌酶活性显著低于D20、D40、D80和D160组(P＜0.05),但与D480组无显著差异(P＞0.05);过氧化氢酶活性呈现先上升后下降趋势,D40组最高.由此可见,本试验条件下,以富马酸亚铁作为铁源,通过折线模型分析发现,以血红蛋白含量和肝脏铁含量为评价指标的虹鳟幼鱼对饲料中铁需要量分别为99.8和100.4 mg/kg.     

杜仲皮水提物对虹鳟生长和肌肉品质、质构特性的影响

本试验旨在研究杜仲皮水提物对虹鳟(Oncorhynchus mykiss)生长和肌肉品质、质构特性的影响。选取体质健康、平均体重(145.56±4.12) g的虹鳟450尾,随机分为5个组,每组3个重复,每个重复30尾。各组分别在基础饲料中添加浓度为0(对照组)、0.5%、1.0%、2.0%和4.0%的杜仲皮水提物。试验期为10周。结果表明:1)各组之间终末体重、增重率、成活率、特定生长率均无显著差异(P>0.05)。2)各组间肌肉pH45 min、pH24 h均无显著差异(P>0.05)。对照组肌肉pH下降率最高,且显著高于2.0%和4.0%组(P<0.05),0.5%和1.0%组显著高于4.0%组(P<0.05)。3)各组间肌肉离心失水率、冷冻渗出率均无显著差异(P>0.05),1.0%组肌肉滴水损失显著高于其他各组(P<0.05)。4) 4.0%组肌肉弹力和弹性显著高于对照组(P<0.05),4.0%组肌肉胶着性和咀嚼性显著高于1.0%组(P<0.05),4.0%组肌肉内聚性显著高于1.0%、2.0%和对照组(P<0.05)。5) 1.0%和4.0%组肌肉肌纤维直径显著低于对照组(P<0.05)。肌肉肌纤维密度随着杜仲皮水提物浓度的增加而增大,0.5%、1.0%、2.0%和4.0%组之间肌纤维密度无显著差异(P>0.05),但均显著高于对照组(P<0.05)。综合以上各项指标,建议饲料中添加浓度为4.0%杜仲皮水提物以改善虹鳟肌肉品质。     

富马酸亚铁对虹鳟幼鱼生长性能、血液生化指标及微量元素含量的影响

本试验旨在研究富马酸亚铁对虹鳟幼鱼生长性能、血液生化指标及微量元素含量的影响。选择初始体重为（８９．２±０．２）ｇ的虹鳟幼鱼 ３６０尾,随机分成 ６组,每组 ３个重复,每个重复 ２０尾鱼,分别饲喂添加富马酸亚铁 ０、２０、４０、８０、１６０、４８０ｍｇ／ｋｇ（以铁计）的试验饲料,各组分别为 Ｄ０、Ｄ２０、Ｄ４０、Ｄ８０、Ｄ１６０和 Ｄ４８０组,Ｄ０组为对照组。各组铁实测含量分别为 ６２．６、７９．５、９９．６、１３９．３、２１５．２、５３８．４ｍｇ／ｋｇ,试验期６０ｄ。结果表明：１）饲料中不同铁水平对虹鳟幼鱼生长性能无显著影响（Ｐ＞０．０５）。２）血红蛋白含量和红细胞数量呈现先上升后平稳的趋势;各组血细胞比容无显著差异（Ｐ＞０．０５）。３）各组全鱼、脊椎骨和肌肉铁含量随着饲料中铁水平的升高而升高,肝脏铁含量呈现先上升后平稳的趋势;各组全鱼锌含量无显著差异（Ｐ＞０．０５）,Ｄ０组脊椎骨和肌肉锌含量显著高于其他各组（Ｐ＜０．０５）,Ｄ０和 Ｄ２０组肝脏锌含量显著高于其他各组（Ｐ＜０．０５）;全鱼铜含量随饲料铁含量的升高而升高,各组脊椎骨铜含量无显著差异（Ｐ＞０．０５）,Ｄ０组肌肉铜含量显著低于其他各组（Ｐ＜０．０５）。４）Ｄ０组血清溶菌酶活性显著低于 Ｄ２０、Ｄ４０、Ｄ８０和 Ｄ１６０组（Ｐ＜０．０５）,但与 Ｄ４８０组无显著差异（Ｐ＞０．０５）;过氧化氢酶活性呈现先上升后下降趋势,Ｄ４０组最高。由此可见,本试验条件下,以富马酸亚铁作为铁源,通过折线模型分析发现,以血红蛋白含量和肝脏铁含量为评价指标的虹鳟幼鱼对饲料中铁需要量分别为 ９９．８和 １００．４ｍｇ／ｋｇ。     

Comparing Sex Steroid Levels During the Annual Cycles of Rainbow Trout (Oncorhynchus mykiss) Diploid Female (XX) and Triploid Female (XXX) Genotypic Sex

In this study, the annual cycle of the gonadal steroids testosterone (T), 11‐ketotestosterone (11‐KT), 17β‐estradiol (E2) and 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) was determined using radioimmunoassay and then compared for two populations of rainbow trout, XX diploid females (n = 40) and XXX triploid females (n = 15). In females, E2 and DHP levels were found to be significantly related to body weight (r = 0.22513; p < 0.0001 and r = 0.15831; p > 0.001, respectively). In this group, E2 concentrations peaked in November (25.05 ng /ml), while maximum DHP levels, only measurable from October to April, were attained in February (64.14 ng /ml). No significant differences in hormone ranges related to egg output ability were observed. Finally, sex steroid concentrations were low in the triploid female XXX fish compared to the female XX population. Nevertheless, maximum T (33.85 ng /ml) and 11‐KT (32.35 ng /ml) levels were recorded in January, for XXX. The levels for these two hormones are relatively high and are also significantly associated (r = 0.8430; p < 0.0001). Diploid females showed significantly higher levels of E2 than triploids over the 12‐month study period. The female triploid fish produced the lowest steroid hormone levels, such that these would be the most suitable for human consumption.     

不同比例膨化豆粕替代鱼粉对虹鳟生长、体成分及血液学指标的影响

本研究旨在研究不同比例膨化豆粕替代鱼粉对虹鳟生长、体成分及血液学指标的影响.试验采用单因素完全随机分组设计,450尾虹鳟鱼,随机分为5个组,每组3个重复,每个重复放养30尾鱼,试验期90 d.选择初始条件一致、体重为(4.00±0.04)g的虹鳟为试验对象,基础日粮中含50%的鱼粉,以膨化豆粕为替代蛋白源并进行植酸酶预处理,各组分别含有0(对照组)、13.60%、27.20%、40.80%和54.40%的膨化豆粕,相应替代基础日粮中0、20%,40%、60%和80%的鱼粉蛋白.结果表明:各试验组虹鳟的脏体比、肥满度、全鱼和肌肉的主要营养成分以及谷草转氨酶、谷丙转氨酶等血清生化指标与对照组差异不显著(P>0.05);随着膨化豆粕替代比例的增加,虹鳟的各项生长及饲料利用指标在对照组与20%～60%的试验组之间差异不显著(P>0.05),与80%的试验组差异显著(P<0.05),其中80%的试验组增重率、特定生长率、蛋白质效率与其他各组相比显著降低(P<0.05),饲料系数显著升高(P<0.05).通过二次多项式同归分析,膨化豆粕替代鱼粉蛋白的最适比例为26.90%.综上所述,在本试验条件下,膨化豆粕对鱼粉蛋白的最大替代量为60%,当替代比例为26.90%时获得最佳生长效果.     

Sex Steroid Levels in XY Males and Sex‐Reversed XX Males,of Rainbow Trout (Oncorhynchus mykiss), During the Reproductive Cycle

In this study, the annual cycle of the gonadal steroids testosterone (T), 11‐ketotestosterone (11‐KT), 17β‐oestradiol (E2) and 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) was determined using radioimmunoassay and then compared, for XY males (n = 35) and sex‐reversed XX males (n = 27) rainbow trout, to establish possible endocrinology differences. Both in XY males and sex‐reversed XX males, significant correlation was shown between body weight and T (r = 0.5046 and 0.34078, respectively; p < 0.0001) or KT (r = 0.52494 and 0.43545, respectively; p < 0.0001) concentrations. Plasma androgen levels in XY and sex‐reversed XX males were similar and showed an intense seasonal variation. The highest levels for T and 11‐KT were detected from December to April with a peak in January (51.67 ± 5.11 and 61.95 ± 4.25 ng/ml, for XY males and 57.1 ± 5.82 and 59.27 ± 4.84 ng/ml, respectively, for XX males). In addition, there was a positive correlation (p < 0.0001) between T and 11‐KT levels for XY males (r = 0.7533) and sex‐reversed XX males (r = 0.6019). Concentrations of DHP in XY males also showed seasonal variation with a peak in February (25.18 ± 12.99 ng/ml). However, DHP levels in sex‐reversed XX males were undetectable (<0.1 ng/ml) over the year. Levels of E2 were undetectable through the year in both groups of trout. In conclusion, the androgenic and oestrogenic profiles of sex‐reversed XX males were similar to those observed in XY males. The only difference in the annual gonadal steroid cycle between XY and sex‐reversed XX males was in the DHP profile.     

切达奶酪粉部分替代鱼粉对虹鳟幼鱼生长性能、体成分及血浆生化指标的影响

本试验旨在研究用切达奶酪粉(cheddar cheese by-products,CCB)部分替代鱼粉对虹鳟(Oncorhynchus mykiss)幼鱼生长性能、体成分和血浆生化指标的影响.用切达奶酪粉分别替代基础饲料中0、15%、30%和45%的鱼粉蛋白质,同时逐渐降低豆油使用量,配成4个等氮等能的试验饲料,并分别...     

Cloning and characterization of a homologue of the alpha inhibitor of NF-kappaB in Rainbow trout (Oncorhynchus mykiss)

A homologue of IkappaBalpha, the alpha member of the IkappaB family of NF-kappaB inhibitors, was identified in a Rainbow trout suppression subtractive hybridization library enriched in sequences up-regulated in cultured leukocytes after lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFalpha) stimulation. The full-length cDNA was isolated and sequenced. The predicted amino acid sequence is 61.5% similar and 54% identical to human IkappaBalpha, while only 42% similar and 35% identical to IkappaBbeta, and 38% similar and 32% identical to IkappaBvarepsilon. Rainbow trout IkappaBalpha contains a central ankyrin repeat domain required for its interaction with NF-kappaB and a putative PEST-like sequence in the C-terminus. Expression of IkappaBalpha is up-regulated by LPS and TNFalpha treatment, two known activators of NF-kappaB, suggesting the existence of an autoregulatory loop in fish, as is the case for mammals. These results confirm the existence of the NF-kappaB signalling pathway in fish and suggest a similar functional interaction between IkappaBalpha and NF-kappaB.     

Protection of rainbow trout (Oncorhynchus mykiss) from lactococcosis by probiotic bacteria

We analysed the effect of probiotic supplementation on the control of lactococcosis in rainbow trout. Probiotic strains Leuconostoc mesenteroides CLFP 196 and Lactobacillus plantarum CLFP 238 were administered orally to fish for 30 days at 10(7) CFU g(-1) feed. Thirty days after the start of the probiotic feeding, fish were challenged with Lactococcus garvieae. Probiotic supplementation reduced fish mortality significantly, from 78% in the control group to 46-54% in the probiotic groups.     

Two new records of helminth parasites of domestic cat from Uruguay: Alaria alata (Goeze, 1782) (Digenea, Diplostomidae) and Lagochilascaris major Leiper, 1910 (Nematoda, Ascarididae)

Eight helminth taxa were recovered from the necropsy of four stray domestic cats from Colonia Miguelete, county of Colonia, Uruguay. Two of them are recorded for the first time for domestic cats in that country: Alaria alata (Goeze, 1782) from the small intestine (which is also the first trematode species found in domestic cat in Uruguay), and Lagochilascaris major Leiper, 1910 from the pharynx. The remaining helminth species found were Toxocara mystax (Zeder, 1800) and Spirometra sp. from the small intestine, Trichuris serrata (von Linstow, 1879) from the caecum, Eucoleus aerophilus (Creplin, 1839) from the trachea, and Pearsonema feliscati (Diesing, 1851) from the urinary bladder. Moreover, four female specimens of an unidentified Spiruroidea were collected from the stomach and small intestine of one host.