Decreased blood cell counts were not observed in cattle living in the “difficult‐to‐return zone” of the Fukushima nuclear accident     

Itaru Sato  Jun Sasaki  Hiroshi Satoh  Yoshitaka Deguchi  Hiroyuki Chida  Masahiro Natsuhori  Kumiko Otani  Keiji Okada 《Animal Science Journal》2019,90(1):128-134

White blood cells, especially lymphocytes, are susceptible to radiation exposure. In the present study, red blood cell, total white blood cell, and lymphocyte counts were repeatedly measured in cattle living on three farms located in the “difficult‐to‐return zone” of the Fukushima nuclear accident, and compared with two control groups from unaffected areas. Blood cell counts differed significantly between the two control groups, although almost all the values fell within the normal range. The blood cell counts of the cattle in the “difficult‐to‐return zone” varied across sampling times even on the same farms, being sometimes higher or lower than either of the two control groups. However, neither a statistically significant decrease in blood cell counts nor an increase in the rate of cattle with extremely low blood cell counts was observed overall. The estimated cumulative exposure dose for the cattle on the most contaminated farm was within a range of 500–1000 mSv, exceeding the threshold for the lymphopenia. Because of the low dose rate on these farms, potential radiation damages would have been repaired and have not accumulated enough to cause deterministic effects.  相似文献   

Effects of high ambient temperature on plasma metabolomic profiles in chicks          下载免费PDF全文

Shozo Tomonaga  Hirofumi Okuyama  Tetsuya Tachibana  Ryosuke Makino 《Animal Science Journal》2018,89(2):448-455

Exposure to high ambient temperature is detrimental to the poultry industry. To understand the influence from a metabolic perspective, we investigated the effects of exposure to high ambient temperature on plasma low‐molecular‐weight metabolite levels in chicks using gas chromatography/mass spectrometry‐based non‐targeted metabolomic analysis. Heat exposure for 4 days suppressed growth and food intake. Of the 92 metabolites identified, the levels of 29 decreased, whereas the levels of nine increased. We performed an enrichment analysis on the identified metabolites and found 35 candidates for metabolic processes affected by heat exposure. Among them, the sulfur amino acid metabolic pathway was clearly detected and the levels of the following related metabolites were decreased: cystathionine, cysteine, cystine, homocysteine and hypotaurine. Changes in the kynurenine pathway in tryptophan metabolism, which is linked to the immune system and oxidative stress, were also observed: kynurenine and quinolinic acid levels increased, whereas nicotinamide levels decreased. These results suggest the possible involvement of various metabolic processes in heat‐exposed chicks. Some of these metabolites would be important to understand the mechanism of biological responses to high ambient temperature in chicks.  相似文献   

Oxidative stress and bovine liver diseases: role of glutathione peroxidase and glucose 6-phosphate dehydrogenase   总被引：1，自引：0，他引：1  

Abd Ellah MR  Okada K  Yasuda J 《The Japanese journal of veterinary research》2007,54(4):163-173

This article summarizes the different types of free radicals, antioxidants and the effect of oxidative stress on the activities of glutathione peroxidase and glucose 6-phosphate dehydrogenase in bovine liver diseases. A growing body of evidence suggests that the formation of reactive oxygen species is a common occurrence associated with most if not all disease processes. The overall importance of reactive oxygen species to the progression and severity of various disease states varies greatly depending on the conditions and whether the disease is acute or chronic. Free radical researches in animals are in progress and further investigations are needed to establish the involvement of reactive oxygen species in diseases affecting different animal species and the pathology they produce.  相似文献   

Characterization of Aquimarina hainanensis isolated from diseased mud crab Scylla serrata larvae in a hatchery     

Yuki Midorikawa  Tomohito Shimizu  Tetsuya Sanda  Katsuyuki Hamasaki  Shigeki Dan  Mohammad Tamrin Bin Mohamad Lal  Goshi Kato  Motohiko Sano 《Journal of fish diseases》2020,43(5):541-549

Mass mortality due to necrosis signs occurred in hatchery-reared zoea stage larvae of the mud crab Scylla serrata in Okinawa, Japan, and a causative bacterium was isolated. In this study, we identified and characterized the bacterium by genome analysis, biochemical properties and pathogenicity. The bacterium was a Gram-negative, non-motile, long rod, forming yellow colonies on a marine agar plate. It grew at 20–33°C (not at 37°C) and degraded chitin and gelatin. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Aquimarina hainanensis. Genome sequence data obtained from Illumina MiSeq generated 29 contigs with 3.56 Mbp in total length and a G + C content of 32.5%. The predicted 16 chitinase genes, as putative virulence factors, had certain homologies with those of genus Aquimarina. Experimental infection with the bacterium conducted on larvae of four crustacean species, brine shrimp Artemia franciscana, freshwater shrimp Caridina multidentata, swimming crab Portunus trituberculatus and mud crab S. serrata, revealed that this bacterium was highly virulent to these species. The present study suggests that the bacterium caused mass mortality in mud crab seed production was A. hainanensis and can be widely pathogenic to crustaceans.  相似文献   

Interspecific differences in the post-settlement survival of <Emphasis Type="Italic">Acropora</Emphasis> corals under a common garden experiment     

Go Suzuki  Wataru Okada  Youko Yasutake  Sayaka Kai  Yuji Fujikura  Iwao Tanita  Hiroshi Yamashita  Takeshi Hayashibara  Wataru Ando  Koichi Nogami  Masayuki Fudo 《Fisheries Science》2018,84(5):849-856

Extremely low post-settlement survival is one of the largest barriers for artificial rehabilitation of Acropora corals. However, little data have been found for interspecific difference of the post-settlement survival probably because the observation of coral juvenile is difficult in the field. Here, we analyzed the survival of three dominant species of Acropora corals (A. digitifera, A. tenuis, A. yongei), with different colony morphologies and habitat preferences, for 2 years after settlement under the same environmental conditions. The post-settlement survival was significantly higher for A. tenuis than for A. digitifera 3 months after settlement. Two years later, the survival rate of A. tenuis was approximately 15 times higher than A. digitifera. In a separate analysis of three bottle-brush species (A. awi, A. echinata, A. subglabra) and A. tenuis, post-settlement survival was always higher for A. awi than for other two bottle-brush species, suggesting that the initial survival was different among morphologically sister species. Low survival was possibly associated with slow growth rates during the first 7 months. Thus, species selection is important for successful artificial coral rehabilitation, with A. tenuis being the most viable option. Alternatively, new techniques are required to improve post-settlement survival of slow growing coral species.  相似文献   

First feeding of diploid and triploid yellowtail tetra Astyanax altiparanae: An initial stage for application in laboratory studies          下载免费PDF全文

Rafaela Manchin Bertolini  José Augusto Senhorini  Nivaldo Ferreira do Nascimento  Matheus Pereira‐Santos  Laura Satiko Okada Nakaghi  Wellington Adriano Moreira Peres  Regiane Cristina da Silva  George Shigueki Yasui 《Aquaculture Research》2018,49(1):68-74

In this study, the aim was to establish a protocol for first feeding of diploid and triploid yellowtail tetra Astyanax altiparanae in laboratory conditions. The fry were fed with five different diets: (i) Artemia franciscana nauplii, (ii) plankton, (iii) dry food, (iv) Artemia franciscana nauplii + plankton, and (v) Artemia nauplii + plankton + dry food. Additionally, the growth and survival rates of diploid and triploid individuals were also evaluated. On day 10, the length of the fish between the treatments differed significantly (p = .0001) and ranged from 4.07 ± 0.06 mm (dry food) to 8.50 ± 0.64 mm (plankton + Artemia). The sizes of the fish increased with time, except for the fish fed with dry food. The survival rates were similar for the fish fed with the four diets and ranged from 80.7 ± 5.4% (dry food + plankton + Artemia to 92.0 ± 1.6% (plankton + Artemia), but differed from the fish fed with dry food (17.7 ± 5.8%, p = .0017). Diploids and triploids did not present differences on day 0 (p = .2252) and on day 10 (p = .4844) when the fish presented 6.77 ± 0.25 mm and 6.54 ± 0.15 mm respectively. Survival of diploids (87.3 ± 5.13%) and triploids (74.67 ± 2.30%) were also similar (p = .0285). These data are innovative and useful for establishing protocols for this species in both academic and applied sciences.  相似文献   

First report of sclerotinia rot of mango caused by <Emphasis Type="Italic">Sclerotinia sclerotiorum</Emphasis> in Japan     

Atsushi Ajitomi  Tetsuya Takushi  Atsushi Ooshiro  Maki Yamashiro  Satoshi Taba 《Journal of General Plant Pathology》2018,84(1):70-72

A panicle blight with sclerotia was found on mango (Mangifera indica L.) in Okinawa Prefecture, Japan, in March 2016. Water-soaked lesions with white mycelia developed on panicles in the flowering stage; softening and decay of panicles was followed by formation of sclerotia. The fungus isolated from these sclerotia was identified as Sclerotinia sclerotiorum based on morphology and analysis of rDNA-ITS sequences. The isolate reproduced the symptoms on mango panicles in an inoculation test and was reisolated from flower stalks. This is the first report of sclerotinia rot (kinkaku-byo in Japanese) on mango caused by S. sclerotiorum in Japan.  相似文献   

Effect of heat treatment on colour changes of black alder and beech veneers     

Emilia-Adela Salca  Hikaru Kobori  Tetsuya Inagaki  Yoichi Kojima  Shigehiko Suzuki 《Journal of Wood Science》2016,62(4):297-304

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Evolution and spread of glyphosate resistance in Conyza bonariensis in California and a comparison with closely related Conyza canadensis          下载免费PDF全文

M Okada  B D Hanson  K J Hembree  Y Peng  A Shrestha  C N Stewart Jr  S D Wright  M Jasieniuk 《Weed Research》2015,55(2):173-184

Glyphosate‐resistant weeds are an increasing problem in perennial cropping systems in the Central Valley of California, USA. To elucidate the evolutionary origins and spatial spread of resistance, we investigated the geographical distribution of glyphosate resistance and the population genetic diversity and structure of Conyza bonariensis and compared the results with previously studied C. canadensis. Thirty‐five populations from orchards and vineyards across the Central Valley were sampled. Population genetic structure was assessed using microsatellite markers. Population‐level resistance was assessed in glasshouse screening of plants grown from field‐collected seed. Bayesian clustering and analyses of multilocus genotypes indicated multiple origins of resistance, as observed in C. canadensis. Pairwise F_ST analysis detected spatial spread of resistance in the south of the Central Valley, also similar to C. canadensis. The results strongly indicate that the southern valley was an environment markedly more suitable than the northern valley for resistance spread and that spread in Conyza species was driven by increased uniformity of strong selection in the southern valley, due to recent regulation on herbicides other than glyphosate. Accordingly, resistant C. canadensis individuals occurred at high frequencies only in the southern valley, but interestingly resistant C. bonariensis occurred at high frequencies throughout the valley. Expression of resistance showed varying degrees of plasticity in C. bonariensis. The lower selfing rate and substantially greater genotypic diversity in C. bonariensis, relative to C. canadensis, indicate greater evolutionary potential over shorter time periods. Interspecific hybridisation was detected, but its role in resistance evolution remains unclear.  相似文献   

Several possible spawning sites of the Japanese eel determined from collections of their eggs and preleptocephali     

Takeuchi  Aya  Higuchi  Takatoshi  Watanabe  Shun  Miller  Michael J.  Yama  Ritsuno  Fukuba  Tatsuhiro  Okamura  Akihiro  Okino  Tatsufumi  Miwa  Tetsuya  Tsukamoto  Katsumi 《Fisheries Science》2021,87(3):339-352

The spawning area of the Japanese eel is located at the southern part of the West Mariana Ridge in the western North Pacific, but their spawning events have not been observed. To further understand Japanese eel spawning ecology, an interdisciplinary research survey by the R/V NATSUSHIMA (NT14-09, 14 May–4 June 2014) was conducted to detect spawning sites based on the seamount, salinity front, new moon and third quadrant (spawning south of front, west of ridge) hypotheses. Attempts were made to film spawning events with underwater camera systems and to consider if eels might be detected in hydroacoustic observations. Although no Japanese eels or spawning events were video-recorded and no eel aggregations could be clearly identified acoustically, three eggs were collected at two stations in the third quadrant region at or just south of 13° N on 26 and 27 May. Three or four days later, newly hatched preleptocephali were collected at two stations far to the south, including 224 at a station > 160 km southwest of the egg catches, and a few preleptocephali were caught at two stations closer to the egg stations. The eggs and southern preleptocephali were from discrete spawning events, which indicated that at least two spawning sites occurred in May 2014.

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