Morphological reproductive characteristics of testes and fertilization capacity of cryopreserved sperm after the Fukushima accident in raccoon (Procyon lotor)     

Kazuki Komatsu  Tsugumi Iwasaki  Kosuke Murata  Hideaki Yamashiro  Valerie Swee Ting Goh  Ryo Nakayama  Yohei Fujishima  Takumi Ono  Yasushi Kino  Yoshinaka Simizu  Atsushi Takahashi  Hisashi Shinoda  Kentaro Ariyoshi  Kosuke Kasai  Masatoshi Suzuki  Maria Grazia Palmerini  Manuel Belli  Guido Macchiarelli  Toshitaka Oka  Manabu Fukumoto  Mitsuaki A. Yoshida  Akifumi Nakata  Tomisato Miura 《Reproduction in domestic animals》2021,56(3):484-497

Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, we have established an archive system of livestock and wild animals from the surrounding ex-evacuation zone. Wildlife within the alert zone have been exposed to low-dose-rate (LDR) radiation for a long continuous time. In this study, we analysed the morphological characteristics of the testes and in vitro fertilization (IVF) capacity of cryopreserved sperm of racoons from the ex-evacuation zone of the FDNPP accident. The radioactivity of caesium-137 (¹³⁷Cs) was measured by gamma-ray spectrometry, and the measured radioactivity concentration was 300–6,630 Bq/kg in the Fukushima raccoons. Notably, normal spermatogenesis was observed in the seminiferous tubules of the testes, with the germinal epithelium composed of a spermatogenic cell lineage with no evident ultrastructural alterations; freeze-thawing sperm penetration ability was confirmed using the interspecific zona pellucida-free mouse oocytes IVF assays. This study revealed that the chronic and LDR radiation exposure associated with the FDNPP accident had no adverse effect on the reproductive characteristics and functions of male raccoons.  相似文献   

Absorption, tissue distribution, excretion, and metabolism of clothianidin in rats     

Yokota T  Mikata K  Nagasaki H  Ohta K 《Journal of agricultural and food chemistry》2003,51(24):7066-7072

Absorption, distribution, excretion, and metabolism of clothianidin [(E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine] were investigated after a single oral administration of [nitroimino-(14)C]- or [thiazolyl-2-(14)C]clothianidin to male and female rats at a dose of 5 mg/kg of body weight (bw) (low dose) or 250 mg/kg of bw (high dose). The maximum concentration of carbon-14 in blood occurred 2 h after administration of the low oral dose for both labeled clothianidins, and then the concentration of carbon-14 in blood decreased with a half-life of 2.9-4.0 h. The orally administered carbon-14 was rapidly and extensively distributed to all tissues and organs within 2 h after administration, especially to the kidney and liver, but was rapidly and almost completely eliminated from all tissues and organs with no evidence of accumulation. The orally administered carbon-14 was almost completely excreted into urine and feces within 2 days after administration, and approximately 90% of the administered dose was excreted via urine. The major compound in excreta was clothianidin, accounting for >60% of the administered dose. The major metabolic reactions of clothianidin in rats were oxidative demethylation to form N-(2-chlorothiazol-5-ylmethyl)-N'-nitroguanidine and the cleavage of the carbon-nitrogen bond between the thiazolylmethyl moiety and the nitroguanidine moiety. The part of the molecule containing the nitroguanidine moiety was transformed mainly to N-methyl-N'-nitroguanidine, whereas the thiazol moiety was further metabolized to 2-(methylthio)thiazole-5-carboxylic acid. With the exception of the transiently delayed excretion of carbon-14 at the high-dose level, the rates of biokinetics, excretion, distribution, and metabolism of clothianidin were not markedly influenced by dose level and sex.  相似文献   

Characterization of macrolide-resistant Campylobacter coli isolates from food-producing animals on farms across Japan during 2004     

Harada K  Asai T  Kojima A  Sameshima T  Takahashi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(10):1109-1111

We investigated the susceptibilities against 7 antimicrobial agents in Campylobacter jejuni and C. coli isolates from food-producing animals in 2004. In comparison with the results of past surveillance, no significant difference was observed in resistance rates against all of the antimicrobials tested in Campylobacter isolates. However, slight increase of erythromycin (EM) resistance was found in C. coli isolates from pigs. We examined the mutation of the 23S rRNA gene and their susceptibilities against azithromycin, tylosin, and lincomycin in 44 EM-resistant isolates and 28 susceptible isolates of porcine origin. All the EM-resistant isolates contained A2075G in the 23S rRNA gene and showed cross-resistance to azithromycin, tylosin, and lyncomycin.  相似文献   

Antioxidation mechanism studies of caffeic acid: identification of antioxidation products of methyl caffeate from lipid oxidation     

Masuda T  Yamada K  Akiyama J  Someya T  Odaka Y  Takeda Y  Tori M  Nakashima K  Maekawa T  Sone Y 《Journal of agricultural and food chemistry》2008,56(14):5947-5952

As a part of a research project on the elucidation of the chain-breaking antioxidation mechanism of natural phenols in food components, caffeic acid, a polyphenolic acid widely distributed in edible plants, was investigated. The identification and time course analysis of the antioxidation reaction products from methyl caffeate were carried out in the ethyl linoleate oxidation system. The antioxidation reaction produced a quinone derivative of methyl caffeate as an antioxidation product during the initial stage, which was identified by (13)C NMR. The quinone, however, was not the final product, and a further reaction occurred to produce several new peroxides. The isolation and structure determination of the peroxides revealed that they had tricyclic structures, which consisted of ethyl linoleate, methyl caffeate, and molecular oxygen. On the basis of the formation pathway of these products, an antioxidation reaction mechanism of methyl caffeate, including the redox reaction of the caffeate and Diels-Alder reaction of the produced peroxides, was proposed.  相似文献   

Antimicrobial susceptibility of pathogenic Escherichia coli isolated from sick cattle and pigs in Japan     

Harada K  Asai T  Kojima A  Oda C  Ishihara K  Takahashi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(10):999-1003

We examined the 12 antimicrobial susceptibilities of 175 E. coli isolates from sick cattle and pigs by an agar dilution method. Resistance was found in 78.3% of isolates for oxytetracycline, 70.3% of isolates for dihydrostreptomycin, and 49.1% of isolates for ampicillin. When compared with healthy animals reported by Kijima-Tanaka et al., resistance rates for 11 antimicrobial agents were higher in sick cattle than in healthy cattle, and resistance rates for all antimicrobial agents were higher in sick pigs than in healthy pigs. Comparing cattle and pigs, resistance rates to colistin was higher in porcine isolates than in bovine isolates, but was lower in porcine isolates than in bovine isolates for cefazolin. With regard to the association of virulence factors, higher resistance rates to colistin and enrofloxacin were observed in STEC (61 strains) than in non-STEC (57 strains) among porcine isolates, while there were no significant differences in bovine isolates. In conclusion, these results can be considered helpful for adequate selection and prudent use of antimicrobial agents for several types of colibacillosis.  相似文献   

Effect of dexamethasone on the expression of atrogin‐1/MAFbx in chick skeletal muscle          下载免费PDF全文

Kazuki Nakashima  Aiko Ishida  Daichi Ijiri  Akira Ohtsuka 《Animal Science Journal》2016,87(3):405-410

Expression of atrogin‐1/MAFbx, a muscle‐specific E3 ubiquitin ligase, is high under catabolic conditions, that result in muscle atrophy. Messenger RNA (mRNA) expression of atrogin‐1/MAFbx is increased by the glucocorticoid dexamethasone in mammalian skeletal muscle. This study investigated the effects of dexamethasone on expression of atrogin‐1/MAFbx in skeletal muscle of neonatal chicks and in chick myotubes. Chicks were given a single intraperitoneal injection of dexamethasone at a concentration of 10 mg/kg body weight. Twenty‐four hours after dexamethasone administration, the Pectoralis muscle weight of chicks was decreased. mRNA expression of atrogin‐1/MAFbx in skeletal muscle of chicks was significantly increased by dexamethasone administration. Expression of other proteolytic‐related genes (20S proteasome C2 subunit, m‐calpain large subunit, and cathepsin B) in skeletal muscle of chicks was not increased by dexamethasone administration. Chick myotubes were incubated with dexamethasone (1, 10 or 100 µmol/L) for 6 h. Expression of atrogin‐1/MAFbx mRNA in chick myotubes was increased in the presence of all concentrations of dexamethasone. However, expression of other proteolytic‐related genes (20S proteasome C2 subunit, m‐calpain large subunit and cathepsin B) in chick myotubes was not affected by dexamethasone treatment. These results indicate that dexamethasone enhances atrogin‐1/MAFbx expression in chick skeletal muscle, resulting in increased muscle atrophy.  相似文献   

Change of fatty acid composition of white adipose tissue with increasing age in Syrian hamster fed alfalfa or cereal based diet     

Yoshihito SUDA  Hisashi SHINOHARA  Toshiyasu YAMAGUCHI  Toshiaki MATSUDA  Kazuki NAKAGAWA  Yukiko OHTOMO  Akira NISHIDA  Toshihiro YAMAGISHI 《Animal Science Journal》2004,75(1):43-47

The present study's aim was to investigate change of fatty acid composition of white adipose tissue with increasing age in Syrian hamster fed continuously alfalfa (LU) or cereal based diet (F2). A total of 43 Syrian hamsters with male and female, 22 head maintained with mating between sibling in a close herd fed F2 (GN) and 21 head selected for long‐term for large number of weaning pups per a mater using GN fed LU (ALF), were used. Fatty acid composition in adipose tissues taken from the back leg subcutaneous depot, periphery of kidney and reproductive organs at 3, 8 and 13 weeks of age were determined by using a gas chromatograph. Carbon (C)18:0 in GN tended to decrease and C18:1 increased significantly with increasing age, suggesting that Δ9‐desaturase had related adaptively. C18:3 in ALF increased significantly with increasing age. The present results indicate that, although the composition in unsaturated fatty acid (USFA) in both herds was different, the ratio of USFA to saturated fatty acid increased with increasing age suggesting that USFA in GN fed F2 was at a high level compared with in ALF fed LU.  相似文献   

Epistasis among the three major flowering time genes in rice: coordinate changes of photoperiod sensitivity,basic vegetative growth and optimum photoperiod     

Naohiro Uwatoko  Atsushi Onishi  Yuji Ikeda  Manabu Kontani  Atsushi Sasaki  Kazuki Matsubara  Youki Itoh  Yoshio Sano 《Euphytica》2008,163(2):167-175

Flowering time is affected not only by photoperiod sensitivity (PS) but also by basic vegetative growth (BVG) and optimum photoperiod (OP), although their developmental and genetic relationships are not well understood. The present study was carried out in rice to examine to what extent these three developmental components are modified by the three flowering time genes, Se1 (= Hd1), Ef1 and e1 (= m-Ef1), which are known to contribute to flowering time in temperate and tropical regions of rice cultivation. Photoperiodic response curves were estimated under controlled conditions of different growth regimes, using eight near-isogenic lines possessing different combinations of the alleles at the three loci. The results showed that each of the components is greatly affected by the main effect of the genes, temperature and their epistasis, indicating that none of the three genes controls flowering time by altering any single component in PS, BVG or OP. Epistasis was detected more frequently among the three genes than reported before, suggesting that epistasis contributes to flowering time by changing PS, BVG and OP differently. The comparison of the nucleotide sequences suggested that Ef1 is the same as Early heading date 1 (Ehd1). Since the two genes Se1 (= Hd1) and Ef1 (= Ehd1) are known to up-regulate the rice homolog of Arabidopsis FT, it is suggested that the detected epistasis may respond to diverse environments by modulating the CO/FT system conserved in flowering plants.  相似文献   

Two loosely linked genes controlling the female specificity for cross-incompatibility in rice   总被引：1，自引：0，他引：1  

Yohei Koide  Mitsunobu Ikenaga  Yuhei Shinya  Kazuki Matsubara  Yoshio Sano 《Euphytica》2008,164(3):753-760

Cross-incompatibility caused by endosperm abortion was found in advanced generations of backcrossing between the Asian wild (W593) and cultivated (T65wx) rice strains. The near isogenic line, T65WxS ₆ (W593), carrying a segment of chromosome 6 from W593 showed a low seed setting when pollinated with pollen grains of T65wx in spite of the fact that the reciprocal cross gave a high seed setting. The unidirectional or asymmetric crossing barrier was previously explained by an interaction between Cif and cim, both of which acted sporophytically, resulting in the cross-incompatibility reactions in the female (CIF) and male (CIM), respectively. In the genetic model, endosperm abortion is induced only when CIF gametes are fertilized with CIM gametes. This predicted that the double homozygote for Cif and cim might be self-incompatible since the plant expresses both CIF and CIM simultaneously. However, we failed to obtain such a self-incompatible plant by transferring Cif into a cim plant. The present results showed that CIF is controlled not only by Cif but also by an additional gene(s) loosely linked with it. We propose here that Cif ₁ (formerly named as Cif) and Cif ₂ determine CIF. In addition, Cif ₂ and Cim were not separated due to restriction of recombination, which might explain why it is difficult to obtain a self-incompatible rice plant expressing both CIF and CIM.  相似文献   

Re-examination of age and growth of daggertooth pike conger Muraenesox cinereus in the western Seto Inland Sea, Japan     

Shingo Watari  Minoru Murata  Yuichi Hinoshita  Kazuki Mishiro  Shigeyuki Oda  Makoto Ishitani 《Fisheries Science》2013,79(3):367-373

Age determination and growth using otolith rings in Muraenesox cinereus was re-examined in the western Seto Inland Sea, Japan. Previous study in this area indicated that new rings were formed annually from March to May, and then from September to October once individuals had achieved four or five rings. In this study, monthly changes in marginal growth rate indicated that the first ring was formed before November in the year following hatching, and from then on another ring was formed annually in July or August. The birth month was determined to be August based on a peak in monthly change in the gonad somatic index. Estimated von Bertalanffy growth functions were L = 806.6{1 ? exp[? 0.33(t + 0.06)]} and L = 1264.0{1 ? exp[? 0.19(t + 0.15)]} for males and females, respectively. Lengths after 3 years of age in this study were 100 mm longer than those in a previous study for both sexes.  相似文献