Decreased transport of orally administered protein into the blood circulation of developing juveniles of Japanese eel Anguilla japonica     

Osamu Nakamura  Yuzuru Suzuki  Katsumi Aida  Hajime Hatta 《Fisheries Science》2001,67(5):863-869

ABSTRACT: To clarify the quantitative changes in the transport of orally intubated protein into the blood circulation as macromolecules in development, immunoglobulin Y (IgY) extracted from chicken eggs was administered orally to juvenile Japanese eel, Anguilla japonica . For the first experiment, which was performed before the commencement of artificial feeding, the oral delivery of 2.0 μg/0.1 g bodyweight of IgY resulted in a rapid increase in plasma IgY to a maximum of 2.30 μg/mL. However, the transport of IgY into the blood decreased significantly in the experiments that followed, which were performed after 12, 25 and 42 days. During this period, bodyweight increased approximately by a factor of eight, and rapid growth of the stomach was observed histologically. Possible contributions for the development of the alimentary canal to the diminishment of intestinal protein assimilation are discussed.  相似文献   

Chromosomal and Plasmid Diversity of Agrobacterium Strains Isolated from Ficus benjamina Tumors     

Aida Raio  Raffaele Peluso  Xavier Nesme  Astolfo Zoina 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(2):163-174

Agrobacteria were previously isolated from tumors developing on branches and aerial and hypogeous roots of weeping fig plants in Italy and in The Netherlands. A representative group of 48 strains was analyzed by PCR–RFLP of 16S and 16S + IGS ribosomal regions, PCR–RFLP of six Ti plasmid (pTi) regions and characterized for plasmid content. Two groups of agrobacteria were separated by cluster analysis of PCR–RFLP profiles of rrs gene: seventeen strains were similar to the new species Agrobacterium larrymoorei, while the remaining strains were included within the agrobacterium biovar 1 group. Sixteen different plasmid profiles from one to five plasmids were observed. In addition, 21 ribotypes and 20 pTi structures were arranged in many different combinations, showing that fig agrobacteria were characterized by a wide heterogeneity. A general lack of correlation between strain ribotypes and plasmid content was observed.  相似文献   

Trichoderma Biocontrol of Colletotrichum acutatum and Botrytis cinerea and Survival in Strawberry   总被引：1，自引：2，他引：1  

Stanley Freeman  Dror Minz  Inna Kolesnik  Olga Barbul  Aida Zveibil  Marcel Maymon  Yehuda Nitzani  Benny Kirshner  Dalia Rav-David  Alon Bilu  Arnon Dag  Sharoni Shafir  Yigal Elad 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(4):361-370

Trichoderma isolates are known for their ability to control plant pathogens. It has been shown that various isolates of Trichoderma, including T. harzianum isolate T-39 from the commercial biological control product TRICHODEX, were effective in controlling anthracnose (Colletotrichum acutatum) and grey mould (Botrytis cinerea) in strawberry, under controlled and greenhouse conditions. Three selected Trichoderma strains, namely T-39, T-161 and T-166, were evaluated in large-scale experiments using different timing application and dosage rates for reduction of strawberry anthracnose and grey mould. All possible combinations of single, double or triple mixtures of Trichoderma strains, applied at 0.4% and 0.8% concentrations, and at 7 or 10 day intervals, resulted in reduction of anthracnose severity; the higher concentration (0.8%) was superior in control whether used with single isolates or as a result of combined application of two isolates, each at 0.4%. Only a few treatments resulted in significant control of grey mould. Isolates T-39 applied at 0.4% at 2 day intervals, T-166 at 0.4%, or T-161 combined with T-39 at 0.4% were as effective as the chemical fungicide fenhexamide. The survival dynamics of populations of the Trichoderma isolates (T-39, T-105, T-161 and T-166) applied separately was determined by dilution plating and isolates in the mixtures calculated according to the polymerase chain reaction (PCR) using repeat motif primers. The biocontrol isolates were identified to the respective species T. harzianum (T-39), T. hamatum (T-105), T. atroviride (T-161) and T. longibrachiatum (T-166), according to internal transcribed spacer sequence analysis.  相似文献   

Nocturnal/diurnal demand-feeding pattern of yellowtail Seriola quinqueradiata under different keeping conditions   总被引：1，自引：0，他引：1  

Jun Kohbara  Iwao Hidaka  Isao Kuriyama  Mitsushi Yamashita  Masasuke Ichikawa  Kiyoshi Furukawa  Katsumi Aida  F. Javier Sánchez-Vázquez and  Mitsuo Tabata 《Fisheries Science》2000,66(5):955-962

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The maturation of the salmon GnRH system and its regulation by gonadal steroids in masu salmon     

M. Amano  K. Ikuta  S. Kitamura  K. Aida 《Fish physiology and biochemistry》1997,17(1-6):63-70

Pituitary gonadotropin (GTH) secreting cells and brain gonadotropin-releasing hormone (GnRH) secreting neurons are known to be subjected to feedback control by gonadal steroid in teleosts. In masu salmon, Oncorhynchus masou, salmon GnRH (sGnRH) neurons in the ventral telencephalon (VT) and the preoptic area (POA) are involved in the control of GTH cells because sGnRH synthesis in these areas is activated with gonadal maturation. In this study, we attempted to clarify mechanisms of feedback control of sGnRH neurons by gonadal steroids. We examined the effects of 17-methyltestosterone (MT) on sGnRH synthesis in yearling and 2-year-old female fish (which were immature during experimentation in May), and the effects of castration on sGnRH synthesis in underyearling precocious male fish in August. sGnRH synthesis in the POA, but not in the VT, was increased by MT administration in 2-year-old females only, indicating higher sensitivity to MT in the preoptic sGnRH neurons. Castration increased sGnRH synthesis in the VT but not in the POA. These results suggest that sGnRH neurons in the VT and those in the POA are differentially regulated by gonadal steroids.  相似文献   

Trawling for cephalopods off the Portuguese coast—Fleet dynamics and landings composition   总被引：1，自引：0，他引：1  

Tereza Fonseca  Aida Campos  Manuel Afonso-Dias  Paulo Fonseca  Joo Pereira 《Fisheries Research》2008,92(2-3):180-188

Fleet dynamics was addressed for three cephalopod taxa of commercial interest, the squid Loligo vulgaris, the octopuses Octopus vulgaris and Eledone cirrhosa, and the cuttlefish Sepia officinalis, for 48 trawlers of the fish trawling fleet. Landing profiles (LP) were identified based on the species composition of the landings using hierarchical cluster analysis. Four out of a total of 12 different LP were related to cephalopods and other species associated with them.The effects on the landing proportions of a number of variables, year, season and vessel, are analysed for each of the species studied using generalized linear models (GLM). The factor “vessel”, including an ensemble of technical characteristics as well as the abilities of individual skippers, explained most of the model deviance, strongly reinforcing the existence of a fleet component dedicated to catch cephalopods. However, time also explains much of the variation found in the data.Seasonal alternation between landings of octopodidae and cuttlefish was observed within a small group of old trawlers operating mainly off the south coast, following the abundance cycles of these species. For a larger group of more modern trawlers, operating off the western coast, inter-annual shift between octopus and squid was found, together with a well marked seasonal pattern between the catches of cephalopods and horse mackerel.Spatial patterns of activity were identified using vessel monitoring system (VMS) data available for trawlers in Portugal, demonstrating the existence of cephalopod targeting strategies in Portuguese fish trawling activities.  相似文献   

播期和密氮组合对镇麦10号干物质积累及产量的调控效应   总被引：4，自引：0，他引：4  

李东升  温明星  蔡金华  曲朝喜  陈爱大 《麦类作物学报》2015,35(10):1226-1432

为确定江苏淮南麦区红皮强筋小麦高产栽培的适宜播期、种植密度和氮肥施用量,选用红皮强筋小麦新品种镇麦10号作为试验材料,在基施45%复合肥375 kg·hm^-2和尿素150 kg·hm^-2条件下,分析了播期和密氮组合对小麦群体干物质积累和产量的影响。结果表明,播期和密氮组合对镇麦10号产量及干物质积累量有极显著的影响。随着播期的延迟,镇麦10号产量先升后降,穗数和千粒重下降,穗粒数略有增加。11月5日播种较10月20日和11月20日播种分别增产2.26%和10.59%;种植密度对籽粒产量的影响因播期不同而有所差异;种植密度增加有利于提高有效穗数,但降低穗粒数和千粒重。10月20日播种时,提高种植密度不利于产量的增加,在基本苗225×10⁴ 株·hm^-2下平均产量最高,较基本苗300×10⁴ 和375×10⁴ 株·hm^-2分别增产3.52%和9.21%;11月5日和11月20日播种时,籽粒产量随着密度的提高而增加,以基本苗375×10⁴ 株·hm^-2的产量最高,较基本苗225×10⁴ 和300×104株·hm^-2分别增产6.32%、4.89%和4.58%、3.25%。增加追氮量有利于穗数、穗粒数和千粒重的增加,但过量追氮时,穗数、穗粒数和千粒重降低;追施纯氮120 kg·hm^-2可显著提高籽粒产量,追氮量过多过少均不利于产量的增加。早播、增加种植密度、增施氮肥均能促进镇麦10号干物质积累,但不利于产量的提高。在本试验条件下,镇麦10号高产最适播期为11月5日,最优密度为375×10⁴ 株·hm^-2,适宜追氮量为120 kg·hm^-2。  相似文献   

Adequate interval of sGTH administration to induce vitellogenesis, and induction of ovulation by simultaneous administration of sGTH and 17α-hydroxyprogesterone in the Japanese eel     

Narumi Sato  Ichiro Kawazoe  Yuzuru Suzuki and  Katsumi Aida 《Fisheries Science》2000,66(4):644-654

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Molecular cloning of the cDNA encoding the β subunit of thyrotropin and regulation of its gene expression by thyroid hormones in the goldfish, Carassius auratus     

Y. Yoshiura  Y.C. Sohn  A. Munakata  M. Kobayashi  K. Aida 《Fish physiology and biochemistry》1999,21(3):201-210

A cDNA encoding the subunit of thyrotropin (TSH) was isolated from a goldfish (Carassius auratus) pituitary gland cDNA library. By comparing the sequence with other teleost TSHs, a signal peptide of 19 amino acids and a mature hormone of 131 amino acids were predicted for goldfish TSH subunits. The resulting putative mature hormone of 131 amino acids had well-conserved cysteine positions and a putative N-linked glycosylation site; homology was 51–67% with TSHs from other teleosts, 38–43% with tetrapod TSHs, but only 27 and 29% with goldfish GTH-I and -II, respectively. We also examined the effects of thyroid hormones (TH) and thiourea (TU, an inhibitor of TH production) treatments on TSH and GTH subunit gene expressions in the goldfish pituitary gland. After thyroxine (T₄) treatment, circulating T₄ concentration increased and TSH mRNA level decreased. Supressing the amount of circulating T₄ and triiodothyronine (T₃) by TU treatment increased the TSH mRNA level. Moreover, T₄ replacement therapy (simultaneous treatment of both TU and T₄) caused a high level of circulating T₄ and a low level of circulating T₃, and a decrease in the TSH mRNA level. Thus, changing levels of circulating TH exert a negative feedback on the level of TSH subunit mRNA in goldfish in vivo. On the other hand, GTH subunit mRNA levels were not affected by changes in the levels of circulating TH.  相似文献   

Methyltestosterone induces male sensitivity to both primer and releaser pheromones in the urine of ovulated female masu salmon     

H. Yambe  A. Munakata  S. Kitamura  K. Aida  N. Fusetani 《Fish physiology and biochemistry》2003,28(1-4):279-280

We investigated the optimum term of 17α-methyltestosterone (MT) -treatment for behavioral test and changes of plasma sex steroids levels in MT-treated immature male masu salmon, Oncorhynchus masou parr. Behavioral responses of MT-treated fish to the urine of ovulated or immature females were observed in an experimental trough. After 5 min of behavioral tests, plasma sex steroids levels were measured by RIAs. MT-treated fish showed specific behavioral responses to the ovulated female urine. MT-treated fish without exposure to the urine showed no clear changes in plasma 17,20β-dihydroxy-4-pregnene-3-one (DHP). However, plasma DHP in MT-treated fish increased when they were exposed to the urine.  相似文献