A surge-like increase in luteinizing hormone preceding musth in a captive bull African elephant (Loxodonta africana)     

Kaewmanee S  Watanabe G  Keio M  Yamamoto Y  Yamamoto T  Kishimoto M  Nagaoka K  Narushima E  Katayanagi M  Nakao R  Sakurai Y  Morikubo S  Kaneko M  Yoshihara M  Yabe T  Taya K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(3):379-383

This study was conducted to determine the correlation between reproductive hormones and musth in a male African elephant. Changes in circulating luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and immunoreactive (ir-) inhibin and the degree of musth were evaluated for 4 years. LH increased 4 weeks before musth began. The highest concentrations of testosterone and ir-inhibin were observed from April to October. There were positive correlations among testosterone, ir-inhibin and musth behavior. These findings suggested that the surge-like LH in the pre-musth period might stimulate secretion of testosterone and ir-inhibin and thus initiate the musth behavior. This study also suggested that the high LH level before musth might be a useful biomarker for the beginning of the musth season.  相似文献   

Production of mouse fibroblast growth factor 4 in E. coli and its application for isolation and maintenance of mouse trophoblast stem cells in vitro     

Hosoi Y  Ando Y  Arakawa M  Kasuga K  Kojima I  Kobayashi M 《The Journal of reproduction and development》2011,57(5):650-654

Fibroblast growth factor 4 (FGF4) promotes isolation of trophoblast stem (TS) cells from mouse blastocysts and maintenance of TS cells in an undifferentiated state in vitro. To date, commercially available, bacterially expressed human FGF4 (RhFGF4) has been used generally for this purpose. In this study, HismFGF4, a 6x histidine-tagged mouse FGF4, was produced in E. coli and purified using heparin column chromatography. We demonstrated that HismFGF4 (25 ng/ml) more efficiently generates mouse TS cells from a single blastocyst than RhFGF4 (25 ng/ml) and that TS cells isolated and maintained with HismFGF4 retained their ability to differentiate into the trophoblast cell lineage in vitro. In addition, TS cells cultured with HismFGF4 (25 ng/ml) were maintained in an undifferentiated state better than with RhFGF4 (25 ng/ml). To the best of our knowledge, this is the first application of a mouse FGF4 derivative for isolation and maintenance of mouse TS cells.  相似文献   

Chromosome doubling of Lychnis spp. by in vitro spindle toxin treatment of nodal segments     

Takahiro Nonaka  Eriko Oka  Megumi Asano  Sachiko Kuwayama  Hiromu Tasaki  Dong-Sheng Han  Toshinari Godo  Masaru Nakano 《Scientia Horticulturae》2011

Lychnis (Caryophyllaceae) consists of about 30 species distributed throughout the temperate regions of the Northern Hemisphere, from East Asia to Europe. Many Lychnis spp. have high ornamental value and cultivated as pot or garden plants. In the present study, in vitro chromosome doubling of several Lychnis spp. was examined in order to widen their variability in horticultural traits. Initially effect of various spindle toxin treatments [100, 500 or 1000 mg l⁻¹ colchicine (COL), 10, 20 or 50 mg l⁻¹ oryzalin (ORY), or 1, 5, 10 mg l⁻¹ amiprophos-methyl (APM)] of nodal segments of a triploid genotype of L. senno (3x) was investigated on survival of nodal segments and chromosome doubling in nodal segment-derived plantlets. Significantly higher percentage (75.0%) of surviving segments after spindle toxin treatment was obtained in 10 mg l⁻¹ ORY treatment. Flow cytometry (FCM) analysis of leaf tissues showed that 9.4–13.8% of plantlets, which were derived from 10 to 20 mg l⁻¹ ORY, or 5 mg l⁻¹ APM treatments, were hexaploid (6x) or ploidy chimera (3x + 6x, 4x + 6x, 5x + 6x, 3x + 4x + 6x). The results obtained by FCM analysis were confirmed by chromosome observation in root tip cells. Thus 10 mg l⁻¹ ORY treatment of nodal segments is suitable for in vitro chromosome doubling of triploid L. senno. Efficient chromosome doubling was also achieved in diploid L. fulgens (2x) and L. sieboldii (2x) by treating nodal segments with 10 mg l⁻¹ ORY: 68.9–88.7% of nodal segments survived after ORY treatment, and 24.7–26.5% of plantlets derived from ORY-treated nodal segments were tetraploid (4x) or ploidy chimera (2x + 4x) in both species. These results indicate that the in vitro chromosome doubling method established for triploid L. senno may be applicable to a wide range of Lychnis spp. Tetraploid L. fulgens and L. sieboldii showed a compact plant form, and had thick stems and deep green leaves compared with the diploid mother plants. On the other hand, hexaploid L. senno showed very poor growth and died before flowering.  相似文献   

Dietary curcumin supplementation attenuates 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in C57BL mice     

Xi-Jun He  Kazuyuki Uchida  Chiaki Megumi  Nobuaki Tsuge  Hiroyuki Nakayama 《Journal of toxicologic pathology》2015,28(4):197-206

Studies in vivo and in vitro suggest that curcumin is a neuroprotective agent. Experiments were conducted to determine whether dietary supplementation with curcumin has neuroprotective effects in a mouse model of Parkinson’s disease (PD). Treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) significantly induced the loss of dopaminergic cells in the substantia nigra and deletion of dopamine in the striatum, which was attenuated by long-term (7 weeks) dietary supplementation with curcumin at a concentration of 0.5% or 2.0% (w/w). Although curcumin did not prevent the MPTP-induced apoptosis of neuroblasts in the subventricular zone (SVZ), it promoted the regeneration of neuroblasts in the anterior part of the SVZ (SVZa) at 3 days after MPTP treatment. Furthermore, curcumin enhanced the MPTP-induced activation of microglia and astrocytes in the striatum and increased the expression of glial cell line-derived neurotrophic factor (GDNF) and transforming growth factor-β1 (TGFβ1) in the striatum and SVZ. GDNF and TGFβ1 are thought to play an important role in protecting neurons from injury in the central and peripheral nervous systems. These results suggest that long-term administration of curcumin blocks the neurotoxicity of MPTP in the nigrostriatal dopaminergic system of the mouse and that the neuroprotective effect might be correlated with the increased expression of GDNF and TGFβ1. Curcumin may be effective in preventing or slowing the progression of PD.  相似文献   

Quantity-intensity relationship for characterizing ammonium chemistry of Bangladesh soils in reference to clay mineralogy     

Kazuhiko Egashira  Megumi Hagimine  Abu Zofar Md. Moslehuddin 《Soil Science and Plant Nutrition》2013,59(3):377-384

Ammonium chemistry in surface soils collected from major soil series of Bangladesh was studied in terms of quantity-intensity (Q/I) relationship. Soils were classified according to physiography and parent materials; calcareous floodplain soils were dominated by mica and smectite, while non calcareous floodplain soils, terrace soils, and hill soils were dominated by mica or kaolinite and lacked smectite as a major clay mineral. Different Q/I parameters were obtained between soils of smectitic and non-smectitic types. Soils of smectitic type had a high potential buffering capacity which kept the equilibrium activity ratio at a low and fixed level.. The content of labile ammonium was high and estimated to increase with increasing addition of NH₄ ⁺. In contrast, soils of non-smectitic type with a low potential buffering capacity showed a considerable variation of both the equilibrium activity ratio and labile ammonium content, as affected by the application of NH₄ ⁺. Based on the ammonium chemistry, expected N-fertilizer application was compared with the prevailing application method.  相似文献   

Effect of co‐culture with intact embryos on development of bovine separated blastomeres     

Makoto Nagai  Noboru Hori  Michiko Miyamoto  Masanobu Sakaguchi  Yuji Hayakawa  Megumi Kawai  Mitsuo Kita  Tetsuya Furuya  Kei Imai 《Animal Science Journal》2013,84(6):461-465

To improve embryo development in bovine separated blastomeres, we evaluated applicability of co‐culture with intact embryos. The morphological quality of blastocysts derived from separated blastomeres and rate of blastocyst formation were only slightly increased when the cells were co‐cultured with intact embryos, which did not provide significant differences when statistically analyzed. However, the cell count of inner cell mass (ICM), trophectoderm (TE) and total number of cells in Day 8 blastocysts were significantly higher when the cells were co‐cultured with the intact embryos than those with the cells cultured individually (P < 0.05). Transfer of four monozygotic pairs of blastocysts derived from the cells co‐cultured with intact embryos led to three pregnancies even when the blastomeres were produced by in vitro maturation and in vitro fertilization of oocytes collected by ovum pick‐up from elite cows. These results suggest that co‐culturing with intact embryos may enhance development of bovine separated blastomere.  相似文献   

Successful blastocyst production by intracytoplasmic injection of sperm after in vitro maturation of follicular oocytes obtained from immature female squirrel monkeys (Saimiri boliviensis)     

Shinichi WATANABE  Megumi MIURA  Hiromi MORITA  Moeka NISHI  Shin-ichi YOKOTA  Shosaku HATTORI  Hiromichi MATSUMOTO  Emiko FUKUI  Ken Takeshi KUSAKABE  Masanori OCHI  Naomi NAKAGATA  Yasuo KISO  Chieko KAI  Midori YOSHIZAWA 《The Journal of reproduction and development》2021,67(4):265

Advanced reproductive technologies are being applied for the propagation of squirrel monkeys, to ensure their preservation as a genetic resource and the effective use of their gametes in the future. In the present study, oocytes and spermatozoa were collected from live squirrel monkeys, following which piezo intracytoplasmic sperm injection (ICSI) was performed using these gametes. Follicular development was induced by administering equine chorionic gonadotropin (eCG) containing inhibin antiserum to an immature squirrel monkey female. The unilateral ovary was excised after the administration of human chorionic gonadotropin (hCG), to induce ovulation, following which the larger developed follicular oocytes were collected. Follicular oocytes were prepared for ICSI using sperm from the epididymal tail of a unilateral testis extracted from a mature male. The embryos were continuously incubated in CMRL 1066 medium supplemented with 10% (v/v) fetal bovine serum. Embryo culture was performed with cumulus cells. Two experiments of ICSI carried out with three females resulted in 14 mature oocytes from the 49 cumulus-oocyte complexes collected and five embryos, three of which developed into blastocysts. These blastocysts were vitrified, thawed, and transferred to recipient monkeys, but no pregnancies resulted. In conclusion, the present study is the first to successfully produce ICSI-derived blastocysts from MII oocytes obtained by means of hormone administration (a combination of eCG+inhibin antiserum and hCG) and in vitro maturation in immature squirrel monkeys.  相似文献   

Allelopathy assessments for the environmental biosafety of the salt-tolerant transgenic Eucalyptus camaldulensis, genotypes codA12-5B, codA 12-5C, and codA 20C     

Akira Kikuchi  Xiang Yu  Takayoshi Shimazaki  Akiyoshi Kawaoka  Hiroyasu Ebinuma  Kazuo N. Watanabe 《Journal of Wood Science》2009,55(2):149-153

Allelopathy tests were conducted on salt-tolerant transgenic eucalyptus trees conferring bacterial codA gene in the designated net-house conditions under Type II use (contained use) of the Japanese law on environmental biosafety aiming for Type I (field use) application. Three transgenic and corresponding nontransgenic genotypes were employed for four different tests: (1) sandwich bioassay; (2) soil germination method; (3) gas chromatography (GC) for volatile substances from the plants; and (4) high-performance liquid chromatography (HPLC) on phenolic compounds from fresh leaves, which are the primary allelopathic substances on the species. The simple approaches, the bioassays, indicated no significant difference between the transgenic and nongenetically modified genotypes. There was no qualitative difference between the transgenic and nontransgenic lines by GC or HPLC. Absence of any quantitative difference was suggested by repetitive examination and subsequent analysis of variance assessments with the chromatographic methods and bioassays. Moreover, it was also indicated that bioassays should be the primary assessment method for allelopathy in considering the simplicity, speed, low cost, and reproducibility of these methods. Overall, substantial equivalence was considered on the three transgenic genotypes with codA gene when compared with the nontransgenic Eucalyptus camaldulensis lines. The experiments supported the application to isolated field testing of the transgenic Eucalyptus camaldulensis genotypes as the first case and experience in Japanese regulatory approval processes Type I Use for the deliberate release to the environment.  相似文献   

A novel Rice QTL <Emphasis Type="Italic">qOPW11</Emphasis> Associated with Panicle Weight Affects Panicle and Plant Architecture     

Satoshi Okada  Megumi Sasaki  Masanori Yamasaki 《Rice》2018,11(1):53

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Salt and Drought Stress Tolerances in Transgenic Potatoes and Wild Species     

K. N. Watanabe  A. Kikuchi  T. Shimazaki  M. Asahina 《Potato Research》2011,54(4):319-324

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