研究者業績
基本情報
研究分野
1委員歴
4-
2016年4月 - 現在
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2015年4月 - 現在
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2012年4月 - 現在
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2010年4月 - 現在
受賞
1論文
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The Journal of Poultry Science 61 n/a-n/a 2024年
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Animals 12(11) 1434-1434 2022年6月2日For the conservation of endangered avian species, developing gamete preservation technologies is essential. However, studies in oocytes have not been widely conducted. In this study, assuming that the ovaries are transported to a research facility after death, we investigated the effect of ovary storage on oocytes for the purpose of cryopreserving avian female gametes by using a chicken as a model of endangered avian species. After excision, the ovaries were stored at either a low temperature (4 °C) or room temperature for 1–3 days. Ovarian follicles stored under different conditions for each period were examined by neutral red staining, histology, and gene and protein expression analysis. In addition, the pH of the storage medium after preserving the ovaries was measured. Then, ovarian tissues were vitrified to determine the cryopreservation competence. Storing the ovarian tissues at 4 °C kept the follicles viable and morphologically normal for 3 days with slow decline. In contrast, although different storage temperature did not influence follicle viability and morphology after only 1 day of storage, ovarian tissues stored at room temperature rapidly declined in structurally normal follicles, and viable follicles were rarely seen after 3 days of storage. Gene and protein expression analysis showed that apoptosis had already started on the first day, as shown by the higher expression of CASP9 under room temperature conditions. Furthermore, high expression of SOD1 and a rapid decline of pH in the storage medium under room temperature storage suggested the influence of oxidative stress associated with low pH in this condition on the follicle survivability in hen ovarian tissues. Our cryopreservation study also showed that ovarian tissues stored at 4 °C could recover after cryopreservation even after 3 days of storage. The described storage conditions and cryopreservation methods, which preserve chicken follicle survival, will lay the foundation of ovarian tissue preservation to preserve the fertility of wild female birds.
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Metabolites 12(1) 86-86 2022年1月17日To explore metabolic characteristics during the post-hatch developmental period, metabolomic analyses of breast muscle and plasma were performed in chickens. The most significant growth-related changes in metabolite levels were observed between seven and 28 days of age. Some of these metabolites are essential nutrients or reported as growth-promoting metabolites. In the muscle, two imidazole dipeptides—carnosine and its methylated metabolite, anserine—increased with the development. These dipeptide levels may be, in part, regulated transcriptionally because in the muscle mRNA levels of carnosine synthase and carnosine methylation enzyme increased. In contrast, taurine levels in the muscle decreased. This would be substrate availability-dependent because some upstream metabolites decreased in the muscle or plasma. In branched-chain amino acid metabolism, valine, leucine, and isoleucine decreased in the muscle, while some of their downstream metabolites decreased in the plasma. The polyamines, putrescine and spermidine, decreased in the muscle. Furthermore, mRNA levels associated with insulin/insulin-like growth factor 1 signaling, which play important roles in muscle growth, increased in the muscle. These results indicate that some metabolic pathways would be important to clarify metabolic characteristics and/or growth of breast muscle during the post-hatch developmental period in chickens.
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Frontiers in Veterinary Science 6 449-449 2019年12月10日 査読有りLow protein diets (LPs) constitute a reportedly effective form of nutritional therapy for canine chronic kidney disease and cirrhosis. These diets have long been feared to result in reduced muscle mass due to protein catabolism. This adverse effect, however, remains largely unrecognized in veterinary medicine as there are no easily applicable catabolism indicators. Therefore, we focused on urinary creatinine, a metabolite of protein in the urine, and examined whether its ratio to urinary urea nitrogen (UCrn/UN) can be used to assess protein catabolism. In Experiment 1, we first consecutively fed seven healthy beagles an LP, standard protein (SP), and high protein (HP) diet for 1 week each and then measured the UCrn/UN ratio at 2-h intervals from fasting to 16 h post-prandially. We consequently found that the UCrn/UN ratio was significantly elevated in the LP pre-prandially and at all post-prandial measurement points (P < 0.01). No significant differences were observed between the SP and HP. Analysis of fasting plasma amino-acid concentrations revealed that the concentration of methionine was significantly lower in the LP than in the other diets (P < 0.05). Although the effects of this change in amino-acid concentration were unclear, the UCrn/UN ratio was considered having increased due to a deficiency in protein and/or amino acids during LP feeding. In Experiment 2, we continuously fed five healthy beagles an LP for 18 weeks and then measured the UCrn/UN ratio as described above. We also measured changes in body composition with computed tomography. At weeks 10 and 18, the fasting UCrn/UN ratio was significantly higher than it was prior to the start of the LP; however, post-prandially, the UCrn/UN ratio decreased to the point that the significant difference disappeared. Muscle mass decreased at weeks 10 and 18. These results suggest that the fasting UCrn/UN ratio could be used as an indicator of protein catabolism in LP feeding. Our experiments thus indicate that examination of potential increases in the UCrn/UN ratio 1 week after introduction of LP feeding to healthy dogs could enable detection of body protein catabolism in long-term feeding of LP before muscle breakdown occurs.
MISC
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ペット栄養学会誌 20(2) 141-144 2017年<p><tt>草食性の動物においての甘味と苦味の感受性調査はほとんどされていない。そこで、草食動物であるハタネズミを用いて3mMキニーネと0.3、1.0、3.0、5.0mMサッカリンに3mMキニーネを混合した溶液の2瓶法によって飲水調査を行なった。サッカリンとキニーネの混合溶液の飲水量はキニーネ単独溶液に比べ減少傾向にあったが、草食性のハタネズミではマウスで行なわれている甘味物質と酢酸キニー</tt><tt>ネとの組み合わせによる行動調査は難しいと考えられる。 </tt></p>
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Animal Science Journal 2017年
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JOURNAL OF POULTRY SCIENCE 52(3) 213-216 2015年7月Two experiments were conducted to evaluate the effects of incubational oxygen concentration on fatty acid metabolism and heme synthesis in broiler breeder embryos. We measured the hepatic activities of delta-aminolevulinic acid dehydratase (ALAD) and 3-hydroxyacyle Co-A dehydrogenase (3-HADH) as these enzymes are the limiting steps in heme synthesis and fatty acid metabolism, respectively. We found no differences in ALAD activity between days 17 and 20 of incubation; we hypothesize that this is because heme synthesis is relatively constant at the later periods of embryonic development. 3-HADH activity was higher in chicks hatched from eggs incubated under low oxygen conditions during early incubation, while specific ALAD activity was reduced in this group as compared to controls.
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畜産の研究 69(5) 411-416,図巻頭2p 2015年5月鳥類の卵殻には,さまざまな色や斑紋があるが,現在,知られている卵殻色素は大きくプロトポルフィリンとビリベルジンの2種類に分けられる。両卵殻色素には,亜鉛や鉄が結合した異性体の存在も知られている。卵殻色としてのプロトポルフィリンはヒトの目には茶色に,またビリベルジンは青色や緑色に見える。両卵殻色素はいずれも鳥類卵管の卵殻腺部で合成,分泌されて,卵殻表面に沈着するのである。両卵殻色素の沈着のメカニズムは,まずビリベルジンと炭酸カルシウムが同時に分泌され,卵殻が形成されたのちに,その表面にプロトポルフィリンが分泌されるようである。すなわち,卵殻色の下地の色はビリベルジンであり,表面の色や斑紋を決めているのはプロトポルフィリンであると考えられている。したがって,この二つの色素の組み合わせで,鳥類の卵の色や斑紋が,さまざまに変わってくるのである。108種類の家禽や野鳥の卵殻色素を定性的に調べたKennedy and Veversの報告では,鳥類の卵殻のおよそ80%がプロトポルフィリンとビリベルジンを色素にしていることが明らかになっている。
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畜産の研究 69(4) 301-310 2015年4月1日赤外放射(Infrared radiation,略号IR)とは,波長780nmから1mm(1,000μm)までの,可視光線に比べてかなり幅広い波長範囲の電磁波のことで,一般には赤外線と呼ばれている。赤外線は,その波長範囲によってさまざまな分類の仕方がある。国際照明委員会(Commission Internationale de l' Eclairage,略称CIE)による赤外線の分類では,IR-A,IR-BおよびIR-Cに分けられている。IR-Aの波長範囲は,780nm~1,400nm(1.4μm)であり,IR-Bは1.4μm~3.0μm,そしてIR-Cは3.0μm~1,000μm(1mm)のようになっている。国際照明委員会は,オーストリアのウィーンに本部を置き,光,照明,色,色空間などを規定する国際標準化団体である。この他に,赤外線は,近赤外放射,中赤外放射および遠赤外放射のように分けられている。
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POULTRY SCIENCE 94(4) 722-727 2015年4月The ileal apical sodium-dependent bile acid cotransporter (ASBT) plays an essential role in the absorption of bile acids from intestinal lumina. ASBT cDNA has been cloned from mammalian and fish species, and the primary structure of the protein and expression properties of the mRNA have been characterized. In this study, we identified chicken ASBT mRNA by cDNA cloning. Chicken ASBT cDNA consisted of 91 bp of the 5'-untranslated region, 1,083 bp of the coding region, and 1,896 bp of the 3'-untranslated region. The cDNA encoded a protein of 360 amino acids showing significant sequence identity with mammalian and fish ASBT. The amino acid residues known to participate in the functions of mammalian ASBT were conserved in chicken ASBT. Real-time polymerase chain reaction analysis revealed that chicken ASBT mRNA was expressed at markedly higher levels in the ileum and proximal colon/rectum, relatively lower levels in the kidney, and very low levels in the jejunum and cecum. Expression levels in the ileum markedly increased after hatching, reached the highest levels on day 7 posthatching, and then decreased to adult levels. A similar expression pattern was observed in the proximal colon/rectum except for the significant decrease from day 7 posthatching to day 21 posthatching. These results suggest that chicken ASBT functions as a bile acid transporter in the ileum and proximal colon/rectum, particularly during the early posthatching period.
共同研究・競争的資金等の研究課題
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日本学術振興会 科学研究費助成事業 2017年4月 - 2020年3月
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日本学術振興会 科学研究費助成事業 2012年4月 - 2015年3月
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文部科学省 科学研究費 2011年4月 - 2013年3月
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日本学術振興会 科学研究費助成事業 2005年 - 2006年
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日本学術振興会 科学研究費助成事業 2003年 - 2004年