Development and use of an Arctic charr cell line to study antiviral responses at extremely low temperatures          下载免费PDF全文

S L Semple  N T K Vo  A R Li  P H Pham  N C Bols  B Dixon 《Journal of fish diseases》2017,40(10):1423-1439

Arctic charr (Salvelinus alpinus) are the northernmost distributed freshwater fish and can grow at water temperatures as low as 0.2 °C. Other teleost species have impaired immune function at temperatures that Arctic charr thrive in, and thus, charr may maintain immune function at these temperatures. In this study, a fibroblastic cell line, named ACBA, derived from the bulbus arteriosus (BA) of Arctic charr was developed for use in immune studies at various temperatures. ACBA has undergone more than forty passages at 18 °C over 3 years, while showing no signs of senescence‐associated β‐galactosidase activity and producing nitric oxide. Remarkably, ACBA cells survived and maintained some mitotic activity even at 1 °C for over 3 months. At these low temperatures, ACBA also continued to produce MH class I proteins. After challenge with poly I:C, only antiviral Mx proteins were induced while MH proteins remained constant. When exposed to live viruses, ACBA was shown to permit viral infection and replication of IPNV, VHSV IVa and CSV at 14 °C. Yet at the preferred temperature of 4 °C, only VHSV IVa was shown to replicate within ACBA. This study provides evidence that Arctic charr cells can maintain immune function while also resisting infection with intracellular pathogens at low temperatures.  相似文献   

Effects of dietary arachidonic acid on final maturation,spawning and composition of gonad of black sea urchin Diadema setosum (Leske, 1778)     

Hua Thai Nhan  Truong Quynh Nhu  Pham Minh Duc  Hon Jung Liew  Harry Ako  Rajesh Jha 《Aquaculture Nutrition》2020,26(5):1771-1779

This study investigated the effect of dietary arachidonic acid (ARA, 20:4n‐6) on final maturation, spawning performance and composition of the gonad of black sea urchin (Diadema setosum). Four different dietary ARA levels of 0.3 g/kg (Control diet), 1.4 g/kg (ARA 1.4), 2.5 g/kg (ARA 2.5) and 3.7 g/kg (ARA 3.7) were prepared and tested in this feeding trial for 90 days. The result showed that growth in terms of weight was not relatively affected by dietary ARA. Gonadosomatic Index (GSI) of animals were gradually increased in all the diets throughout the trial. The highest GSI level (25.7 ± 3.16%) was observed in animals fed with the diet ARA 1.4. ARA content in the gonad proportionally increased with dietary ARA levels. The highest larval survival rate (85.5 ± 5.67%) was found in diet ARA 2.5. The results of this study indicate that ARA plays an important role in the reproduction functions of black sea urchin and supplementing an appropriate level of ARA in the broodstock diet could induce the final maturation and improve reproduction of black sea urchin, but a higher level of ARA (3.7 g/kg) seems to have a negative effect on both growth rate and GSI.  相似文献   

Fusarium solani haplotype 12-b and aortic and branchial arteritis in Hippocampus erectus Perry     

Tori Brown  Zach Millar  Drake Evans  Phuc H. Pham  Veronique LePage  John S. Lumsden 《Journal of fish diseases》2020,43(2):301-304

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聚碳酸酯板材多点热成形数值模拟与成形精度分析     

曹鋆汇  付文智  李明哲  刘纯国  苏世忠  Pham D T 《农业机械学报》2014,45(1):335-340

提出了用于热塑性聚合物板材的柔性成形技术——多点热成形技术。根据高温单向拉伸试验数据确定了不同温度下聚碳酸酯(PC)板材的超弹性材料模型参数。运用有限元软件Abaqus对不同温度和不同成形压力下的PC板材多点热成形过程进行了数值模拟,结果表明:当成形温度与成形压力分别为160℃和10 kPa时,成形件平均形状误差最小。参照数值模拟结果进行了PC板材的多点热成形试验,验证了数值模拟结果的准确性。测量并分析了成形件的成形精度,结果表明:成形件具有较高的成形精度,可以满足工程应用需要。  相似文献   

Genetic Nature of Yams (Dioscorea sp.) Domesticated by Farmers in Benin (West Africa)     

Nora Scarcelli  Serge Tostain  Cédric Mariac  Clément Agbangla  Ogoubi Da  Julien Berthaud  Jean-Louis Pham 《Genetic Resources and Crop Evolution》2006,53(1):121-130

‘Domestication’ is a traditional farmers’ practice reported for yams (Dioscorea sp.) in Benin (West Africa). It involves introducing ‘spontaneous’ (naturally occurring) yams, supposedly wild (D. abyssinica and D. praehensilis), in varieties of the D. cayenensis–D. rotundata cultivated species complex. In this study, we established the genetic nature of ‘predomesticated’ yam plants using the amplified fragment length polymorphism (AFLP) technique. A total of 213 accessions, consisting of 32 predomesticated yams, 70 D. cayenensis–D. rotundata, 86 D. abyssinica and 25 D. praehensilis yams were analysed. Using 91 AFLP markers, three groups of accessions were distinguished, broadly corresponding to the above botanical species. Of the 32 predomesticated accessions, 16% were clustered with D. praehensilis, 37% with D. abyssinica and the remaining 47% with D. cayenensis–D. rotundata. These results demonstrated the use of wild plants by farmers in their domestication process, and suggested that plants derived from intervarietal and interspecific hybridisation may also be subject to this process. This study has shown that through domestication farmers influence and increase the genetic diversity in yam by using sexual reproduction of wild and possibly cultivated yams.  相似文献   

大豆种子寿命的遗传   总被引：5，自引：0，他引：5  

PhamThiDao  HariHarRam 《大豆科学》1999,18(4):312-317

大豆种子的储存寿命较短,在潮湿、酷热的环境晚是如此。然而,已经筛选出几个种子寿命较长的品种。本研究旨在了解大豆种子寿命（或耐贮性）的遗传,以便通过育种程序来改良该性状。  相似文献   

Formation of Enzyme‐Resistant Starch in Bread as Affected by High‐Amylose Wheat Flour Substitutions     

Pham Van Hung  Makoto Yamamori  Naofumi Morita 《Cereal Chemistry》2005,82(6):690-694

High‐amylose wheat flour was used to substitute for normal wheat flour in breadmaking and formation of resistant starch (RS) in bread during storage was determined. Substitution with high‐amylose wheat flour (HAF) decreased peak and final viscosities, breakdown, and setback. Doughs with HAF substitutions were weaker and less elastic, and absorbed more water than those of the normal wheat flour. After baking, RS contents in breads with 10, 30, and 50% HAF substitutions were 1.6, 2.6, and 3.0% (db), respectively, higher than that of the control (0.9%, db). The levels of RS increased gradually during storage for one, three, and five days. With substitutions of 30 and 50% HAF, the total levels of dietary fiber (DF) and RS in bread after five days of storage were 15.5 and 16.8% (db), respectively, as compared to 13.0% (db) in bread from the normal wheat flour. The loaf volumes and appearances of bread crumbs made from HAF substitutions of 10 and 30% were not significantly different from those of the control, whereas the substitution with 50% HAF decreased loaf volume and resulted in inferior appearance of breadcrumbs. The firmness of breadcrumbs increased along with increase in the level of HAF substitutions after baking. During storage, the firmness of breadcrumb with 10% HAF substitutions was higher than that of the control, whereas breads with 30 and 50% HAF substitutions had similar firmness to the control. As a result, HAF might be used to substitute for up to 50% normal wheat flour to make bread with acceptable bread quality and significantly high amount of RS.  相似文献   

Distribution of lipids and fatty acids in the zooxanthellae and host of the soft coral Sinularia sp.     

Imbs  Andrey B.  Yakovleva  Irina M.  Pham  Long Q. 《Fisheries Science》2010,76(2):375-380

The lipid classes and the fatty acid (FA) compositions of the zooxanthellae, the host tissue, and intact coral were determined for the first time in a soft coral, Sinularia sp. The contents of monoalkyldiacylglycerol (MADAG), triacylglycerol, and polar lipids differed significantly between the zooxanthellae and the host fractions. The zooxanthellae were rich in polar lipids, whereas neutral lipids were concentrated in the host. MADAG comprised 35% of the host lipids and was practically absent in zooxanthellae. Hence, MADAG is only synthesized in animal tissues and serves as a biomarker for the host in the host–zooxanthellae association of these soft corals. Similar to the zooxanthellae of reef-building corals, the main FA in the zooxanthellae of Sinularia sp. were 18:4n-3, 20:5n-3, and 22:6n-3. In addition, 16:3n-4 and 16:4n-1 (8.9% in total) were found in these zooxanthellae. The ratios of 16:3n-4, 16:4n-1, 18:4n-3, 20:5n-3, and 22:6n-3 in the zooxanthellae to those in the host tissue were 4.2, 11.2, 10.1, 11.0, and 9.1, respectively. The proportions of some FA and lipid classes in the intact coral and its fractions showed that zooxanthellate lipids comprised 36 ± 15% of the total lipids in Sinularia sp. Two tetracosapolyenoic acids (24:5n-6 and 24:6n-3) are proposed as a biomarkers of the animal tissue and indicators of the purity of the zooxanthellae fractions from soft corals.  相似文献   

Changes in brain and pituitary GnRH levels during ovarian maturation in wild female Japanese flounder     

Ky Xuan Pham  Masafumi Amano  Noriko Amiya  Yutaka Kurita  Kunio Yamamori 《Fish physiology and biochemistry》2006,32(3):241-248

To elucidate the role of gonadotropin-releasing hormone (GnRH) in gonadal maturation in wild female Japanese flounder Paralichthys olivaceus, we monitored changes in the levels of seabream GnRH (sbGnRH) in the olfactory bulb, telencephalon, hypothalamus, and pituitary during ovarian development together with changes in plasma levels of testosterone (T), estradiol-17β (E₂), and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP). Fish were caught offshore of the northern mainland of Japan in the Pacific Ocean at 3- to 4-week intervals between April and September by gill net. The netted fish were categorized into six groups based on ovarian stages: previtellogenic (April–early May), early yolk (April–late May), late yolk (late May–June), early spawning (June–August), late spawning (September), and termination (September) stages. The gonadosomatic index significantly increased from the previtellogenic to early spawning stages and decreased thereafter. In the olfactory bulb, no significant differences were observed in sbGnRH levels among the developmental stages. In contrast, sbGnRH levels in the telencephalon and hypothalamus were very high in the previtellogenic stage, lower in the early spawning stage, and relatively high in latter stages. sbGnRH levels in the pituitary were high in the previtellogenic stage and low in the early spawning stage. In addition, the relatively high levels of pituitary sbGnRH were found together with high plasma T, E₂, and DHP levels in fish in the late yolk stage. These results indicate that sbGnRH in the telencephalon, hypothalamus, and pituitary is involved in ovarian maturation and that sbGnRH may play an important role in the initiation of ovarian recrudescence in wild Japanese flounder.  相似文献   

Molecular genetic diversity and genetic structure of Vietnamese indigenous pig populations     

L.D. Pham  D.N. Do  L.Q. Nam  N. Van Ba  L.T.A. Minh  T.X. Hoan  V.C. Cuong  H.N. Kadarmideen 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2014,131(5):379-386

The study characterized genetic diversity and genetic structure of five indigenous pig populations (Ha Lang, Muong Te, Mong Cai, Lung and Lung Pu), two wild pig populations (Vietnamese and Thai wild pigs) and an exotic pig breed (Yorkshire) using FAO/ISAG recommended 16 microsatellite markers in 236 samples. All estimated loci were very polymorphic indicated by high values of polymorphism information content (from 0.76 in S0225 to 0.92 in Sw2410). Indigenous populations had very high level of genetic diversity (mean He = 0.75); of all indigenous breeds, Lung Pu showed highest mean number of alleles (MNA = 10.1), gene diversity (He = 0.82), allele richness (5.33) and number of private alleles (10). Thirteen percentage of the total genetic variation observed was due to differences among populations. The neighbour‐joining dendrogram obtained from Nei's standard genetic distance differentiated eight populations into four groups including Yorkshire, two wild populations, Mong Cai population and a group of four other indigenous populations. The Bayesian clustering with the admixture model implemented in Structure 2.1 indicated seven possible homogenous clusters among eight populations. From 79% (Ha Lang) to 98% (Mong Cai). individuals in indigenous pigs were assigned to their own populations. The results confirmed high level of genetic diversity and shed a new light on genetic structure of Vietnam indigenous pig populations.  相似文献