Analysis of genetic and biological characters of Japanese potato strains of <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis>     

Mitsuo Horita  Yasuhiro Suga  Atsushi Ooshiro  Kenichi Tsuchiya 《Journal of General Plant Pathology》2010,76(3):196-207

We assessed the geographic distribution, biovar, phylotype, DNA fingerprints (rep-PCR), and/or endoglucanase sequence of potato bacterial wilt pathogen, Ralstonia solanacearum (Rs), in Japan. Rs has been isolated from potato fields in southwestern, warm, temperate regions. Of the 188 isolates, 74 belonged to biovar N2 (39%), 44 to biovar 3 (24%), and 70 to biovar 4 (37%). Biovars N2 and 4 strains were widely distributed, from northern (Hokkaido) to southern (Okinawa) Japan. Based on the results of multiplex-PCR analysis, every potato strains belonged to either phylotype I or IV. Phylotype I comprised both biovars 3 and 4 strains. On the other hand, phylotype IV included biovar N2 strains. None of the strains belonged to phylotype II or III or biovar 1 or 2. Phylogenetic analysis based on DNA fingerprints and endoglucanase gene sequences clarified the genetic diversity of the Japanese potato strains and the close genetic relationship between the Japanese strains and the Asian strains in phylotypes I and IV.  相似文献   

Antiobese effects of novel saponins from edible seeds of Japanese horse chestnut (Aesculus turbinata BLUME) after treatment with wood ashes     

Kimura H  Ogawa S  Katsube T  Jisaka M  Yokota K 《Journal of agricultural and food chemistry》2008,56(12):4783-4788

Recently, we have identified novel saponins from edible seeds of Japanese horse chestnut ( Aesculus turbinata BLUME) after processing the natural seeds with wood ashes to remove bitterness. We attempted to determine anti-obesity effects of those saponins from edible seeds as well as natural seeds. The purified individual components of saponins from natural and edible seeds inhibited pancreatic lipase in vitro. The potency was in the order of escins > desacylescins > deacetylescins. Escins Ib and IIb as well as deacetylescins Ib and IIb with the angeloyl moiety were more potent than the corresponding Ia and IIa series with the tigloyl moiety. Moreover, in vivo anti-obesity effects of the saponin fractions were monitored for 8 weeks in mice fed high-fat diets. Saponin fractions from both seeds significantly attenuated the elevation in body weight, the mass of peritoneal adipose tissues, and plasma triacylglycerol, which was accompanied by higher contents of undigested fats in feces without changes in food intake, indicating the effective inhibition of fat digestion in vivo. Taken together, saponin fractions including desacylescins and deacetylescins from edible seeds are potentially useful for the development of nutraceutical foods with anti-obesity effects and more attenuated bitter taste.  相似文献   

Life in the fast lane: Revisiting the fast growth—High survival paradigm during the early life stages of fishes     

Dominique Robert  Jun Shoji  Pascal Sirois  Akinori Takasuka  Ignacio A. Catalán  Arild Folkvord  Stuart A. Ludsin  Myron A. Peck  Su Sponaugle  Patricia M. Ayón  Richard D. Brodeur  Emily Y. Campbell  Evan K. D'Alessandro  John F. Dower  Louis Fortier  Alberto G. García  Klaus B. Huebert  Marc Hufnagl  Shin-ichi Ito  Mikimasa Joh  Francis Juanes  Mitsuo Nyuji  Yoshioki Oozeki  Guido Plaza  Motomitsu Takahashi  Yosuke Tanaka  Naoki Tojo  Shingo Watari  Naotaka Yasue  Pierre Pepin 《Fish and Fisheries》2023,24(5):863-888

Early life survival is critical to successful replenishment of fish populations, and hypotheses developed under the Growth-Survival Paradigm (GSP) have guided investigations of controlling processes. The GSP postulates that recruitment depends on growth and mortality rates during early life stages, as well as their duration, after which the mortality declines substantially. The GSP predicts a shift in the frequency distribution of growth histories with age towards faster growth rates relative to the initial population because slow-growing individuals are subject to high mortality (via starvation and predation). However, mortality data compiled from 387 cases published in 153 studies (1971–2022) showed that the GSP was only supported in 56% of cases. Selection against slow growth occurred in two-thirds of field studies, leaving a non-negligible fraction of cases showing either an absence of or inverse growth-selective survival, suggesting the growth-survival relationship is more complex than currently considered within the GSP framework. Stochastic simulations allowed us to assess the influence of key intrinsic and extrinsic factors on the characteristics of surviving larvae and identify knowledge gaps on the drivers of variability in growth-selective survival. We suggest caution when interpreting patterns of growth selection because changes in variance and autocorrelation of individual growth rates among cohorts can invalidate fundamental GSP assumptions. We argue that breakthroughs in recruitment research require a comprehensive, population-specific characterization of the role of predation and intrinsic factors in driving variability in the distribution and autocorrelation of larval growth rates, and of the life stage corresponding to the endpoint of pre-recruited life.  相似文献   

The relationship between paralarval feeding and morphological changes in the proboscis and beaks of the neon flying squid <Emphasis Type="Italic">Ommastrephes bartramii</Emphasis>     

Kazuhisa Uchikawa  Mitsuo Sakai  Toshie Wakabayashi  Taro Ichii 《Fisheries Science》2009,75(2):317-323

We compared the diet of Ommastrephes bartramii paralarvae with morphological changes in their beaks and proboscis (fused tentacles). The paralarvae were collected north of the Hawaiian Islands during 2001 and 2002 and ranged in mantle length (ML) from 1.1 to 13.2 mm. They fed on crustaceans, including copepods (copepodite stage) and amphipods. The rostral tips of upper and lower beaks began to protrude anteriorly at around 3–4 mm ML, and the smallest paralarva with identifiable prey in its digestive tract was 4.2 mm ML, which suggests that the paralarvae can masticate prey soon after the beaks protrude. The proboscis separated into two tentacles at 9.3–13.2 mm ML, but the newly formed tentacles were weakly developed even in the largest specimen, suggesting that tentacles do not operate functionally and that the arms are used to capture prey.  相似文献   

Immunoreactive changes in pituitary FSH and LH cells during seasonal reproductive and spawning cycles of female chub mackerel <Emphasis Type="Italic">Scomber japonicus</Emphasis>     

Mitsuo Nyuji  Tetsuro Shiraishi  Sethu Selvaraj  Vu Van In  Hajime Kitano  Akihiko Yamaguchi  Kumiko Okamoto  Shizumasa Onoue  Akio Shimizu  Michiya Matsuyama 《Fisheries Science》2011,77(5):731-739

The physiological functions of pituitary gonadotropins (GtHs) are well established in higher vertebrates, whereas those in teleosts are still poorly understood. To describe the role of GtHs during gonadal development of female chub mackerel Scomber japonicus, changes in follicle-stimulating hormone (FSH) and luteinizing hormone (LH) cells were investigated immunohistochemically during the seasonal reproductive and spawning cycles. FSH and LH cells were identified in the different cell types of the proximal pars distalis (PPD); FSH cells were located in the central PPD, whereas LH cells were localized along the border of the pars intermedia. To examine changes in FSH and LH cells, the percentage of FSH or LH cell-occupying area in the PPD was evaluated and represented as FSHβ-immunoreactive (ir) or LHβ-ir levels, respectively. FSHβ-ir levels increased significantly from immature to the completion of vitellogenesis, whereas LHβ-ir levels were maintained at high levels from early vitellogenesis to post-spawning. During the spawning cycle, which consisted of four stages from just after spawning to the next oocyte maturation, both FSHβ-ir and LHβ-ir levels showed no significant changes among different stages; however, LHβ-ir levels remained relatively high, and FSHβ-ir levels were constantly low. These results suggest that both FSH and LH may be involved in vitellogenesis and LH may act at final oocyte maturation in female chub mackerel, although the role of FSH during the spawning cycle is still unclear.  相似文献   

Direct estimation of stock abundance of Pacific saury <Emphasis Type="Italic">Cololabis saira</Emphasis> in the northwestern Pacific Ocean using a mid-water trawl     

Yasuhiro Ueno  Satoshi Suyama  Masayasu Nakagami  Miyako Naya  Mitsuo Sakai  Yutaka Kurita 《Fisheries Science》2017,83(1):23-33

Drifting gill-nets were for a long time the main research gear for investigating the distribution of Pacific saury Cololabis saira. However, it has proven to be difficult to estimate the absolute abundance of saury using drifting gill-nets due to a lack of knowledge on the survey areas swept by these gill-nets. A mid-water trawl stock abundance estimation has the advantage of being able to estimate the absolute stock abundance before the commercial fishing season begins, whereas the conventional stock abundance estimation based on catch per unit efforts of commercial fisheries must be done after the commercial fishing season has ended. To confirm the practicality of a mid-water trawl to estimate the stock abundance of saury, we conducted a comparative survey in the northwestern Pacific Ocean using both a mid-water trawl and drifting gill-nets. We found that the geographic distribution pattern of catch per unit effort for both the mid-water trawl and driftnets was similar. Using the area-swept method and data on the fishing efficiency of the mid-water trawl obtained in a previous study, we were able to estimate the stock abundance plus confidence limits within the research areas. Our results suggest that the size composition of saury sampled by the mid-water trawl can be considered to approximate the actual size composition of saury.  相似文献   

Dual appearance of xanthophores,and ontogenetic changes in other pigment cells during early development of Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis>     

Mitsuo Nakamura  Tadahisa Seikai  Masato Aritaki  Reiji Masuda  Masaru Tanaka  Masatomo Tagawa 《Fisheries Science》2010,76(2):243-250

Flatfishes display a left–right asymmetry that is unique in the animal kingdom. In order to clarify the mechanisms of the asymmetrical development of pigment cells, changes in pigment cell densities were examined in Japanese flounder Paralichthys olivaceus. During development from symmetrical larvae to asymmetrical juveniles, pigment cell densities were monitored on the skin on both the left side (ocular side in juvenile; eventually has two eyes) and the right side (blind side in juvenile; eventually has no eyes). A symmetrical and constant decrease was observed in leucophores and larval type melanophores. A mostly symmetrical (slightly delayed on the blind side) and constant increase in iridophores from metamorphosis was observed. Adult-type melanophores appeared and then increased only after metamorphosis on the ocular side. However, the pattern of xanthophores was complicated: they first existed symmetrically and decreased symmetrically until metamorphosis, and they later increased only on the ocular side. The dual appearance of the xanthophores, as well as the differences between their depths and sizes on the ocular and blind sides, may suggest the presence of two types of xanthophores—just as melanophores are well known to exhibit two types. The ontogenetic study of pigment cells described here is likely to help to elucidate the process of abnormal pigmentation in flatfishes.  相似文献   

Seedling rot of garland chrysanthemum caused by Gibellulopsis chrysanthemi and ecological characters of the causal fungus     

Mitsuo Kawaradani  Kiyoshi Taguchi  Kiyotsugu Okada  Yuuri Hirooka  Toyozo Sato 《Journal of General Plant Pathology》2013,79(5):346-349

A new disease found on garland chrysanthemum in Osaka, Japan in 2009 and its causal agent were identified and characterized. Light brown spots first appeared on lower leaves of seedlings, and the leaves blighted or rotted. A fungus isolated from diseased plants, described recently as Gibellulopsis chrysanthemi, was demonstrated to reproduce the natural symptoms in inoculation tests. Sufficiently long, moist periods after inoculation promoted the infection even after lengthy dry periods. The pathogen also caused the disease on chrysanthemum and lettuce, but not on seven other vegetables. The fungus caused the disease after 6 months of dry storage. The disease was termed seedling rot (“nae-fuhai-byo” in Japanese).  相似文献   

Pathogenicity evaluation of Ralstonia pseudosolanacearum race 4 on ginger by leaf-clipping inoculation     

Iiyama  Kazuhiro  Imamura  Momoka  Inoue  Tomomi  Kyaw  Htet Wai Wai  Yano  Kazutaka  Horita  Mitsuo  Tsuchiya  Kenichi  Furuya  Naruto 《Journal of General Plant Pathology》2021,87(5):269-272

Journal of General Plant Pathology - An easy, rapid method has been needed to test the pathogenicity of strains of Ralstonia pseudosolanacearum, the cause of serious bacterial wilt on ginger...  相似文献   

Cerebellar Ataxia Suspected to Be Caused by Oxytropis glabra Poisoning in Western Mongolian Goats     

Shuji TAKEDA  Hiroyuki TANAKA  Akinori SHIMADA  Takehito MORITA  Atsushi ISHIHARA  Altanchimeg ADILBISH  Bayarmunkh DELGERMAA  Oyuntsetseg GUNGAA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(6):839-846

  相似文献