Triploid Induction in the Yellowtail Tetra,Astyanax altiparanae,Using Temperature Shock: Tools for Conservation and Aquaculture          下载免费PDF全文

Nadya Soares de Macedo Adamov  Nivaldo Ferreira do Nascimento  Elayna Cristina Silva Maciel  Matheus Pereira‐Santos  José Augusto Senhorini  Leonardo Luiz Calado  Mariana Machado Evangelista  Laura Satiko Okada Nakaghi  Alan Hertz Marín Guerrero  Takafumi Fujimoto  George Shigueki Yasui 《Journal of the World Aquaculture Society》2017,48(5):741-750

Triploidization is an interesting tool to produce sterile fish. In the yellowtail tetra, Astyanax altiparanae, this can be applied for aquaculture and surrogate technologies. In this study, we compared the efficacy of cold (2 C) or heat shock (38 C, 40 C, and 42 C) on triploid induction in the yellowtail tetra. The eggs were treated with cold or heat shock, 2 min postfertilization (30 min in cold shock or 2 min in heat shock). Intact embryos served as the control group. Ploidy status was confirmed by karyotyping, flow cytometry, and nuclear diameter of erythrocytes. The hatching rate decreased after cold shock (12.69 ± 15.76%) and heat shock at 42 C (0.35 ± 0.69%) in comparison with the control group (63.19 ± 16.82%). At 38 C and 40 C, hatching rates (61.29 ± 17.73% and 61.75 ± 22.1%, respectively) were not decreased. Only one triploid arose at 38 C (1/80). At 40 C, a high number of triploids arose (72/78). At 42 C, very few embryos developed into the hatching stage. A large number of haploid individuals arose after cold shock (61/75), with only one triploid. Our results indicate that heat shocking of embryos at 40 C is optimum for triploid production in the yellowtail tetra.  相似文献   

Construction of an expression vector for improved secretion of canine IL-18     

Sugiura K  Akazawa T  Fujimoto M  Wijewardana V  Mito K  Hatoya S  Taketani S  Komori M  Inoue N  Inaba T 《Veterinary immunology and immunopathology》2008,126(3-4):388-391

To construct a vector for caspase-1 independent expression of canine IL-18, the signal sequence of canine IL-12p40 was fused to the sequence of mature IL-18 on the NdeI restriction site which is located at the 3' end of the signal sequence. The resulting vector expressed coding protein from transfected mammalian cells. The expressed protein was shown to have IL-18 bioactivity in a INF-gamma-inducing assay. These results suggest that the expression vector is the desired tool for advancement of dendritic cell (DC)-based cancer therapy, provided that the vector can successfully be transfected into dendritic cells. We propose a simple and widely applicable method for providing the signal sequence.  相似文献   

A double‐blind,placebo‐controlled evaluation of orally administered heat‐killed Enterococcus faecalis FK‐23 preparation in atopic dogs     

Takafumi Osumi  Takashi Shimada  Masahiro Sakaguchi  Hajime Tsujimoto 《Veterinary dermatology》2019,30(2):127-e36

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Codend selectivity for jack mackerel and whitefin jack and unequal split parameter estimates observed in trouser trawl experiments     

Mohamed Salah Mahjoub  Seiichi Takeda  Toshifumi Hayashi  Daisuke Shiode  Takafumi Arimoto  Tadashi Tokai 《Fisheries Science》2011,77(2):169-181

Codend selectivity for the jack mackerel Trachurus japonicus and the whitefin jack Kaiwarinus equula were evaluated based on data from trouser trawl experiments carried out in the East China Sea, using a test codend of 60 mm diamond mesh and a control codend made of minnow net with a square mesh of 9 mm bar length. Between-haul variations in parameters and the mean selection curves were tested with the catch data in the SELECT approach, and then the model of between-haul variation in the split parameter with the mean selection curve was chosen as the best fit using Akaike’s information criterion model selection. The 50% retention lengths and the selection ranges were 11.4 and 3.36 cm for jack mackerel and 8.83 and 0.93 cm for whitefin jack, respectively. The selection curve for whitefin jack was sharp, whereas that for jack mackerel was relatively wide. As the estimated split parameters indicated, about 80% of the whitefin jack entered the control codend, but 85 and 90% of the jack mackerel entered the control codend in the second and third hauls, respectively. The inequality in the split parameter is discussed from the viewpoint of the animal’s swimming behavior and water movement based on underwater video observations.  相似文献   

Fatigue analysis of the jack mackerel <Emphasis Type="Italic">Trachurus japonicus</Emphasis> by electrocardiographic monitoring during prolonged swimming     

Ruobing Cheng  Mochammad Riyanto  Takafumi Arimoto  Kazutaka Yanase 《Fisheries Science》2017,83(1):73-82

The effect of fatigue on swimming performance was examined by measuring the swimming endurance time and heart rate of the jack mackerel Trachurus japonicus [15.7 ± 0.8 cm fork length (FL), n = 15] during forced exercise in a flume tank at fixed swimming speeds of 4, 5 and 6 FL/s. Electrocardiographic (ECG) monitoring during the experimental process from control (0.8 FL/s) to exercise phase revealed a rapid cardiac response of T. japonicus to the elevation of swimming speed. The heart rate of T. japonicus significantly increased from the control level of 52.9 beats/min at a slow flow speed of 0.8 FL/s to 148.2 beats/min at 4 FL/s, 168.6 beats/min at 5 FL/s and 183.2 beats/min at 6 FL/s. During the fixed speed test, the heart rate of each individual fish was stabilized without any recognizable increase or decrease until the fish failed to swim because of fatigue. Fatigue analysis on endurance time demonstrated that prior swimming experience at prolonged speeds would impair the endurance performance during subsequent swimming exercise. Recovery time of the heart rate after the fish was fully exhausted by prolonged fast exercise increased with increasing swimming endurance time.  相似文献   

Effects of an Enterococcus faecium‐based probiotic on growth performance and health of Pirarucu,Arapaima gigas     

Natalino da Costa Sousa  Mrcia Valria Silva do Couto  Higo Andrade Abe  Peterson Emmanuel Guimares Paixo  Carlos Alberto Martins Cordeiro  Emilly Monteiro Lopes  Jonathan Stuart Ready  Gabriel Fernandes Alves Jesus  Mauricio Latera Martins  Jos Luiz Pereira Mourio  Paulo Csar Falanghe Carneiro  Alexandre Nizio Maria  Rodrigo Yudi Fujimoto 《Aquaculture Research》2019,50(12):3720-3728

Intensive fish farming has resulted in an increased concern for disease outbreaks. Probiotic use is one of the strategies being developed to improve fish health and productivity. Measures of probiotic colonization, growth performance, haematological characteristics and parasite load were used to evaluate the effect of diets supplemented with Enterococcus faecium on growth and health of Arapaima gigas juveniles. A completely randomized design with four treatments (diet with E. faecium at 1 × 10⁶ CFU/g and 1 × 10⁸ CFU/g, control diet and diet with the culture medium MRS) and three replicates was used. Ninety‐six Arapaima juveniles were distributed in 12 cages fed with the specified diet for 68 days. Colonization of the intestinal tract by lactic acid bacteria reduced the total number of heterotrophic bacteria in fish fed with probiotics compared to controls. Fish fed a supplemented diet containing 1 × 10⁸ CFU/g presented higher values of weight gain, survival and fish growth uniformity, and lower values of feed conversion ratio. The prevalence of Trichodina sp. could have affected the survival of fish in the control group. Reduction in parasite load and an increase in haematocrit, the number of erythrocytes, thrombocytes, neutrophils and monocytes were also observed in fish fed the diet containing 1 × 10⁸ CFU/g. Enterococcus faecium presented a probiotic effect in A. gigas juveniles and can be recommended for use at a concentration of 1 × 10⁸ CFU/g to modify the gut microbiota, improve growth performance and haematology and reduce parasitic load.  相似文献   

Artificially induced tetraploid masu salmon have the ability to form primordial germ cells     

Suzu Sakao  Takafumi Fujimoto  Terumasa Kobayashi  Goro Yoshizaki  Etsuro Yamaha  Katsutoshi Arai 《Fisheries Science》2009,75(4):993-1000

Diploid gametes generated with tetraploid animals are a stepping stone to improving chromosome manipulation techniques. However, artificially induced tetraploid individuals generally die soon after hatching. Diploid gametes could be induced by in vivo cultures of tetraploid primordial germ cells (PGCs) through germ-line chimera. In the present study, characteristics of PGCs were studied in inviable tetraploid masu salmon, Oncorhynchus masou. Histological observation of tetraploid embryos revealed that the same or smaller numbers of PGCs were observed and they migrate into the genital ridges as did diploid PGCs during gonadogenesis. By whole-mount in situ hybridization using vasa messenger RNA (mRNA), 4–35 vasa-positive signals were detected in a pair of genital ridges of tetraploids. By cytological observation of genital ridge cell suspensions, several large round cells were observed, some of which extended pseudopodia. They also contained large nuclei and round granules in their cytoplasm, characteristics of PGCs. As the results suggest that inviable artificial tetraploids have PGCs, we expect to achieve diploid gamete production through surrogate propagation and tetraploid fish production.  相似文献   

Nationwide seroprevalence of Neospora caninum among dairy cattle in Japan   总被引：3，自引：0，他引：3  

Koiwai M  Hamaoka T  Haritani M  Shimizu S  Zeniya Y  Eto M  Yokoyama R  Tsutsui T  Kimura K  Yamane I 《Veterinary parasitology》2006,135(2):175-179

Serum samples from 2420 clinically healthy dairy cattle, randomly selected from stored sera in 18 districts of Japan, were tested for the presence of Neospora caninum antibodies using an indirect fluorescent antibody test (titer > or =1:200). Nationwide seroprevalence is estimated at 5.7% (139/2420). Seropositive cattle were detected in all surveyed districts despite the evidence of confirmed case reports of bovine neosporosis, showing that N. caninum is widely distributed throughout Japan. Age-specific seroprevalence did not increase with cattle age, suggesting that Neospora infection is likely to be transmitted vertically rather than horizontally in Japan. Considering that N. caninum seropositive cows are thought to be more likely to abort, substantial fetal losses may be induced by N. caninum infection in Japan. Devising strategies are needed to reduce the economic impact on the Japanese dairy industry. This is the first study to investigate the nationwide seroprevalence of N. caninum in cattle in Asia.  相似文献   

Sr isotopic compositions of ayu otolith and its ambient water     

Hiroshi Amakawa  Takafumi Suzuki  Toshiro Takahashi  Yoshiyuki Tatsumi  Tsuguo Otake 《Fisheries Science》2012,78(5):1023-1029

Sr isotopic compositions of ayu otolith and water collected from Japanese rivers were measured to validate the relationship between otolith and ambient water for this species. Micromilling and rostrum-cut methods employed for otolith sampling were compared and yielded almost indistinguishable otolith Sr isotopic composition data. A good correlation observed between data on otolith and those on ambient water (river water and sea water) confirms the usefulness of Sr isotopic composition for elucidating migratory behavior of ayu, as already verified in other species.  相似文献   

The effect of irradiance and temperature on the photosynthesis of two agarophytes Gelidium elegans and Pterocladiella tenuis (Gelidiales) from Kagoshima,Japan     

Midori Fujimoto  Gregory N. Nishihara  Ryuta Terada 《Fisheries Science》2014,80(4):695-703

The effect of irradiance and temperature on the photosynthesis of two Japanese agarophytes, Gelidium elegans and Pterocladiella tenuis (Gelidiales), was determined using dissolved oxygen sensors and pulse amplitude modulated (PAM) fluorometry. Gross photosynthesis and dark respiration rates were determined over a range of temperatures (8–36 °C). The highest gross photosynthetic rates were 40.3 and 37.0 mg O₂ g _ww ^?1  min^?1 and occurred at 24.3 and 25.5 °C [95 % Bayesian credible interval (BCI) 20.7–28.0 and 23.4–28.3 °C], respectively. The dark respiration rate in G. elegans and P. tenuis increased with increasing temperature at a rate of 0.10 and 0.31 mg O₂ g _ww ^?1  min^?1 °C^?1 , respectively. Modeling the net photosynthesis–irradiance (P–E) responses of G. elegans and P. tenuis at 20 °C revealed that the net photosynthetic rates quickly increased at irradiance levels below the estimated saturation irradiance of 88 and 83 µmol photons m^?2 s^?1, with a compensation irradiance of 14 and 19 µmol photons m^?2 s^?1, respectively. The highest value of the maximum effective quantum yield (Φ _PSII) occurred at 20.1 °C (BCI 18.9–21.5 °C) and 21.3 °C (BCI 20.2–22.5 °C) for G. elegans and P. tenuis and was 0.49 and 0.45, respectively. These optimal temperatures of Φ _PSII were relatively lower than those determined by the photosynthesis–temperature model of oxygen evolution. The temperature response of these species indicates that they are probably well adapted to the current range of seawater temperatures in the study site but that they are near the boundary of their tolerable limits.  相似文献