著者

山本 かおり 坪田 敏男 喜多 功

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.44, no.5, pp.j13-j18, 1998-06-01

参考文献数

21

被引用文献数

3 25

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秋田県阿仁クマ牧場において1996年6月22日から7月31日まで,ニホンツキノワグマ <i>Ursus thibetanus japonicus</i>(成獣雄22頭, 雌17頭)の性行動を観察した.本観察場所でのニホンツキノワグマの交尾期は6月中旬から8月上旬であると考えられた.乗駕行動は不特定多数の雌雄間で見られ,交尾形態としては乱交型であった.雌はある一定の期間に集中して雄の乗駕を許容(これを発情とみなした)し,発情期間は12~35日間と大きな個体差がみられた.また,発情期間と非発情期間が不規則に繰り返される傾向があり,発情様式にも大きな個体差がみられた.雄の性行動は,雌の発情に同調して発現すると推測された.乗駕が観察された総日数は,4歳および5歳の雄において有意に少なく(p<0.05),6歳以上の雄に関しては体重の重い雄(80kg以上)において多い傾向があった(p<0.1).このことから,本観察場所のような高密度な飼育条件下においては,年齢や体重による優劣関係の社会構造が発達し,生理的に性成熟に達した後も,社会的要因によって交尾の機会を持たない雄が存在することが推測された.<br>

著者

武内 歩 加藤 めぐみ 伊藤 和美 木村 建 花田 章 平林 真澄 保地 眞一

出版者

日本繁殖生物学会

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.48, no.3, pp.243-248, 2002-06-01

参考文献数

28

被引用文献数

2 9

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The aim of this study was to investigate the effect of Ca²⁺- and Mg²⁺-free culture conditions on induction of spontaneous first cleavage in rat oocytes. Oocytes recovered from superovulated Wistar females 17 h after hCG injection were exposed for 1.5 h to Ca²⁺/Mg²⁺-free, Ca²⁺-free, Mg²⁺-free, or control mKRB medium supplemented with 5 &mu;g/ml cytochalasin-B (CB). The oocytes were then cultured for 4.5 h in control medium containing CB and for 28 h in CB-free control medium. The oocytes exposed to the Ca²⁺/Mg²⁺-free medium (23%) cleaved better than those exposed to Ca²⁺-free (8%), Mg²⁺-free (0%), or control (0%) media. The cleavage rates of oocytes recovered 12, 17 and 22 h after hCG injection and exposed to the Ca²⁺/Mg²⁺-free medium were 4, 17 and 22%, respectively. The efficiency of oocyte activation in 1.25 mM Sr²⁺ treatment for 6 h was not influenced by the culture background of bivalent cations (cleavage rates: both 49% in Ca²⁺/Mg²⁺-free and Ca²⁺-free medium). These results indicate that Ca²⁺/Mg²⁺-free culture condition induced the spontaneous first cleavage of rat oocytes in an age dependent manner, but had no additional effect on Sr²⁺-induced oocyte activation.

著者

富永 敬一郎

出版者

Japanese Society of Animal Reproduction

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.50, no.1, pp.29-38, 2004-02-01

参考文献数

56

被引用文献数

3 20

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胚に対するグリセリンの浸透圧ショックを緩和するために希釈時に用いられるスクロースの細胞毒性を緩和することを目的として、ストロー内でスクロースによるグリセリン希釈を行った後、さらに、胚に影響しない濃度まで培養液で希釈するストロー内2段階希釈直接移植法を開発した。野外での体内回収胚移植で、この方法はエチレングリコールを用いたダイレクト法と同等の受胎率であった。16細胞期胚の緩慢凍結法において、最適耐凍剤を選定するとともに、リノール酸アルブミンの培養液への添加や、遠心処理で細胞内脂肪を局在化させることによる胚細胞外への除去を試みた。その結果、エチレングリコール区がプロパンディオール区やDMSO区より胚盤胞への発生率が高く、LAA添加は無添加に比べて凍結融解後の胚盤胞への発生率を向上させた。また、2細胞期で遠心処理した16細胞期胚では脂肪大部分除去区の凍結融解後の胚盤胞への発生率は無遠心凍結区より高く、無遠心新鮮区の胚盤胞の細胞数と差はみられなかった。次に、体外受精後2細胞期から胚盤胞期までの胚について、ゲル・ローディング・チップ(GL-ip)を用いた超急速ガラス化法を検討した結果、すべての発育日齢で50%を越える高い胚盤胞への発生率が得られ、発生率及び胚盤胞の細胞数、細胞構成において、それぞれの日齢の新鮮胚対照区と差はみられなかった。また、体外受精7日目胚盤胞のGL-ipガラス化法は緩慢凍結法より生存率が高かった。体内回収胚の発生速度の速い胚盤胞や形態の良好な高品質胚に雄が多いが、この関係は交配種雄牛毎に異なることを明らかにした。また、個体毎に区別した体外受精由来胚では、胚の発生速度あるいは胚盤胞生産率と性別とに関係がみられないことや、切断2分離胚後、雄胚が高品質胚へ早く形態回復することを明らかにした。性判別した体内回収胚にGL‐ipガラス化法を応用した結果、対照の新鮮胚移植と変わらない受胎率が得られた。体外受精由来3、4日目胚から1-2割球をサンプリングし、サンプルをPEP‐PCR、DNA産物を精製し、性判別PCRに供した。同時に、サンプリング胚を7日目まで培養し、発生した胚盤胞をGL-ipガラス化した。その結果、性別が高率に判定でき、ガラス化した胚盤胞は新鮮胚と変わらない高い生存率が得られ、しかも、ガラス化胚が子牛への発生能を持つことを明らかにした。

著者

Kudo Toshiyuki Yamamoto Hiroaki Sato Seiji SUTOU Shizuyo

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.42, no.2, pp.101-107, 1996-05-01

参考文献数

28

被引用文献数

1 10

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Aromatase (EC 1.14.14.1.) is a key enzyme of feminizing hormone biosynthesis and catalyzes the conversion of androgens to estrogens. In birds, sex-steroid hormones, especially estrogens, play a critical role in the development of the gonadal glands and the aromatase is one of the most important factors in sex determination. Herein, we cloned the 5' upstream regions of chicken and quail aromatase genes and determined these sequences, which showed high homology between chicken and quail. Moreover, the transcription initiation site of the chicken aromatase gene in early development was determined by the 5'-RACE method. The findings showed that the transcription of the chicken aromatase gene starts from a more upstream site than previously reported.

著者

表記なし

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.52, no.1, pp.143-144, 2006-02-01

著者

村上 周子 柴谷 雅美 竹内 宏佑 SKARZYNSKI Dariusz J. 奥田 潔

出版者

Japanese Society of Animal Reproduction

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.49, no.6, pp.531-538, 2003-12-01

被引用文献数

5 24

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ウシ子宮内膜を構成する上皮細胞および間質細胞のプロスタグランディンF2α(PGF)合成は、それぞれオキシトシン(O;上皮細胞)、および腫瘍壊死因子(NF;間質細胞)により促進される。本研究では、ウシ子宮内膜から単離し、継代培養および凍結保存した上皮ならびに間質細胞が子宮機能の解析に供することができるかを、OおよびNFに対するPGF合成の反応性から検討した。ウシ子宮(発情周期Days2-5)より単離した内膜上皮および間質細胞をPrimary細胞とし、約半量を培養、残りの半量を凍結後(-80C)、融解、培養した。また、Primary細胞を4回継代培養し、継代ごとに細胞の半量を次の継代に用い、残りの半量を凍結後、融解、培養した(Passage 1-4)。コンフルエントに達した後、NF(1ng/m1)またはO(100ng/m1)を添加し、4時間培養後、上清中のPGF濃度を測定した。継代および凍結融解した細胞に形態的な変化は認められなかった。間質細胞のPGF基底合成能に凍結および継代の影響は認められなかったが、凍結により上皮細胞の基底合成能は有意に低くなった。また、上皮細胞のみPassage2以降に基底合成量が有意に低くなったが、上皮はPassage2まで、間質はPassage4までそれぞれO、NFへの有意な反応性を示した。以上から、上皮細胞は1回まで、間質細胞は少なくとも4回まで継代および凍結保存しても子宮機能の解析に十分なPGF合成能を有することが明らかとなった。

著者

橋爪 力 高橋 優子 沼田 恵 SASAKI Koichi UENO Kimiko OHTSUKI Kenji KAWAI Mami ISHII Aya

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.45, no.4, pp.273-281, 1999-08-01

被引用文献数

5 29

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The objectives of this research were to characterize plasma profiles of growth hormone (GH), prolactin (PRL) and insulin-like growth factor-I (IGF-I) during gestation and the lactation period in goats, as well as in their suckling growing kids. There were no obvious changes in the GH or PRL profiles during gestation, but secretion of both GH and PRL increased acutely after parturition. The elevated GH concentrations were maintained until 3 months after parturition, whereas the PRL concentrations decreased gradually after parturition. The elevated hormone concentrations are thought to be caused mainly by an increase in the secretory pulse amplitudes. In contrast to the GH and PRL profiles, the plasma IGF-I concentrations during late gestation were significantly higher than the post-parturition concentrations, and the IGF-I concentrations in late gestation decreased gradually until the day of parturition. The plasma GH, PRL and IGF-I concentrations in kids 1 week after birth were high, and concentrations of each hormone decreased thereafter. These results show that the increased secretory potencies of pituitary GH and PRL after parturition are caused mainly by an increase in the secretory pulse amplitudes and that plasma GH is inversely related to plasma IGF-I compared over gestation and the lactation period in goats.

著者

Brussow Klaus-Peter Torner Helmut Ratky Jozsef 眞鍋 昇 TUCHSCHERER Armin

出版者

Japanese Society of Animal Reproduction

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.52, no.2, pp.249-257, 2006-04-01

被引用文献数

1

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ブタにおいては卵管における貯留精子の放出と排卵の関連には不明な点が多い。あらかじめ子宮角頭部に少量の精子を注入した卵子除去法、メスブタの卵管内に卵子-卵丘細胞複合体を注入した後、卵管を摘出して膨大部、頭部と尾部の精子数、初期胚数と発生ステージなどを調べた。卵子-卵丘細胞複合体を注入しない場合と比較して膨大部と頭部の精子数が増加した。この効果はnon-sulfaed glycosaminoglycan hyaluronan(HA)とともに卵子-卵丘細胞複合体を注入した場合に顕著であり、受精して胚盤胞まで発生が進む初期胚の割合も高くなった。これらから、ブタでは卵管の精子貯留部からの精子放出に卵子-卵丘細胞複合体が影響し、HAがその効果を高めることがわかった。

著者

Korzekwa Anna J. 奥田 潔 Woclawek-Potocka Izabela 村上 周子 SKARZYNSKI Dariusz J

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.52, no.3, pp.353-361, 2006-06-01

被引用文献数

9 54

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We previously showed in <i>in vivo</i> and <i>in vitro</i> studies that nitric oxide (NO) is engaged in luteolysis in cattle. Nitric oxide produced locally in the bovine corpus luteum (CL) inhibits progesterone (P4) synthesis and is suggested to be a component of the luteolytic cascade induced by uterine prostaglandin (PG) F₂_α. In the present study, the molecular mechanisms of NO action during structural luteolysis were studied in cultured bovine luteal cells (Days 15-17 of the estrous cycle). The effects of the NO donor (NONOate; 10^-4M) on DNA fragmentation, cell viability, P4 production and caspase-3 activity were compared with those of PGF₂_α (10^-6M). Moreover, mobilization of intracellular calcium [Ca²⁺]_i and gene expressions of Fas-L, Fas, bcl-2, bax, and caspase-3 in the cells were determined by semi-quantitative RT-PCR after NONOate treatment. Caspase-3 activity was examined calorimetrically. Contrary to PGF₂_α NONOate decreased cell viability. DNA fragmentation after NONOate treatment increased by more than with PGF2₂_α. NONOate increased mobilization of [Ca²⁺]_i in the cells. Although the NO donor did not affect Fas-L and bcl-2 gene expression, it stimulated Fas and bax mRNA and caspase-3 expression. The ratio of bcl-2 to bax mRNA level decreased in the cells treated with NONOate. Moreover, NONOate stimulated caspase-3 activity more effectively than PGF₂_α. The overall results suggest that NO is a luteolytic factor that plays a crucial role in regulation of the estrous cycle in structural luteolysis by inducing apoptosis of luteal cells in cattle.<br>

著者

Mutai Hideki Hattori Naka Kamei Takayuki AIKAWA Jun-ichi SHIOTA Kunio OGAWA Tomoya

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.41, no.4, pp.353-359, 1995-11-01

被引用文献数

1

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One of the target tissues for prolactin (PRL) family members is the central nervous sytem (CNS) in adult animals. In this study, we tried to detect PRL receptor (PRL-R) mRNAs in fetal rat brains. mRNAs extracted from various tissues, including the brain, on embryonic days 12 (E12), 14, 16, 18 and 20 were subjected to reverse transcriptional polymerase chain reaction (RT-PCR) using two sets of primers specific to the short and long forms of the PRL-R. The short form cDNA band (330 bp) was detected in the fetal brain from E12 to 20, whereas the long band (420 bp) was not apparently observed, suggesting that the developing fetal brain is a target for PRL family members. Short form PRL-R mRNA was also expressed in the liver (E20), heart (E12 to 20), intestine (E16 to 20) and forelimb (E20), and long form PRL-R was observed in the heart on E20. Semi-quantitative PCR analysis revealed that short form PRL-R mRNA expression in the fetal brain was as biphasic: constant on E12 and 14, and increased progressively on E18 and 20. Thus, PRL-R gene expression is initiated very early in developing fetal tissues, including the CNS.

著者

Itagaki Yoshiaki Kimura Naoko Yamanaka Masaya MUNETA Yoshihiro

出版者

THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

雑誌

The Journal of reproduction and development (ISSN:09168818)

巻号頁・発行日

vol.43, no.1, pp.53-58, 1997-02-01

被引用文献数

2

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This study was undertaken to determine the relationship between the first cleavage division of <i>in vitro</i> produced (IVP) bovine embryos and the following few cleavage divisions in culture. The "early-", "intermediate-" and "late-" cleaving embryos presented at 22, 26 and 30 h post insemination (hpi) were cultured separately until they were fixed and stained with Hoechst 33342 at the end of each culture period (30, 48, 72, 96 and 120 hpi). Distributions of embryos that underwent the first cleavage at 22, 26 and 30 hpi were 21.5, 34.7 and 10.0%, respectively. No significant difference among the mean number of cells in the 3 groups was observed until 48 hpi. At 72 hpi, the number of cells in the early-cleaving embryos (10.8 ± 0.5) was higher than those in the intermediate- and late-cleaving embryos (8.7 ± 0.4 and 6.5 ± 0.6, respectively). Higher numbers of cells were also observed in the early-cleaving embryos (18.0 ± 1.5) at 120 hpi, compared with those in the intermediate- and late-cleaving embryos (12.5 ± 0.8 and 11.4 ± 1.5, respectively). More than 80% of the early- and intermediate-cleaving embryos had completed the second cleavage division at 48 hpi, whereas that of the late-cleaving embryos was lower (56.5%). No difference in the proportion of >8-cell embryos among the 3 groups was observed at 48 hpi (22.9 vs 24.7 vs 26.1%). However, the completion of the third cleavage in the early-cleaving embryos was higher than in the intermediate- and late-cleaving embryos at 72 hpi (65.4 vs 49.4 vs 25.0%), and from there onwards (96 hpi; 81.1 vs 63.2 vs 45.5%, 120 hpi; 83.6 vs 62.2 vs 65.0%). The proportion of >16-cell embryos in the early-cleaving embryos was also higher than that of the intermediate- and late-cleaving embryos between 96 hpi (18.9 vs 2.9 vs 0.0%) and 120 hpi (49.1 vs 22.0 vs 25.0%). Our results suggest that the development of IVP bovine embryos is possibly controlled as early as at the 2-cell stage, and the differences between the early and late cleaving embryos are associated with 1) the developmental delay or arrest of embryos during the second cleavage, and 2) the lengthening of the third cleavage, which seems to be related to the subsequent developmental ability of the embryos.