著者

寺本 研 森 森裕介 長野 邦寿 早坂 郁夫 沓掛 展之 池田 功毅 長谷川 寿一

出版者

一般社団法人 日本霊長類学会

雑誌

霊長類研究 (ISSN:09124047)

巻号頁・発行日

vol.23, no.1, pp.33-43, 2007 (Released:2009-01-01)

参考文献数

23

被引用文献数

6 6

---

Chimpanzees are a naturally highly sociable species. Therefore, it is desirable to keep captive individuals in a social group. Although the dyadic introduction method has been commonly used to form social groups, it has not always been successful. In the present study, we tested a new method to create three all-male groups, two of which consisted of .ve individuals, and one of nine individuals. This method requires three stages. First, male dyads were put into neighboring cages in which the individuals could see each other. Tentative social rank was determined by observing the males' behaviors in these dyadic encounters. Next, they were moved to an unfamiliar environment and housed individually. Several days later, they were introduced one by one to an outside enclosure. Three allmale groups have been maintained so far, suggesting that group formation was successful. The occurrence of severe injury was considerably lower than that seen commonly in multi-male multi-female groups. Moreover, signi.cant effects of the group formation on male behavior (e.g., increased number of active social behaviors and decreased abnormal behaviors) were observed. These results demonstrate the effectiveness of our new method of forming all-male chimpanzee groups.

著者

鵜殿 俊史 寺本 研 早坂 郁夫

出版者

日本霊長類学会

雑誌

霊長類研究 (ISSN:09124047)

巻号頁・発行日

vol.15, no.2, pp.243-250, 1999 (Released:2009-09-07)

参考文献数

15

被引用文献数

4 6 2

---

The Kumamoto Primates Park, Sanwa Kagaku Kenkyusho CO., Ltd. had successfully bred chimpanzee from 1982 to 1999. The breeding statistics of 100 pregnancies, observed for the 17 years, were reviewed. The breeding females were 24 wild born and 3 captive born. Neonatal diagnoses were performed on the next day of the birth. Of 100 pregnancies, diagnosed by urinary CG test and/or ultrasonography, 11 resulted in abortions, 5 in stillbirths, and 85 in live births (containing a monozygotic twins). The mean birth weight and gestational period of 84 live born infants was 1793g (n=74, 930-2400) and 229.4 days (n=84, 181-250). Seven of 11 abortions occurred in early stage of pregnancies (45-65 days). Infant mortality in the first year of life was 10.7%: 6 died from 7 to 16 days of age, 3 died after 50 days of age. Three of dead 6 neonates were low birth weight (under 1500g). There was no infant died under 7 days of age or over 1 year of age. Perinatal mortality was calculated at 0.12. 73.2% of deliveries occurred in the nighttime (n=82). Placentaphagia were observed in 65.7% cases of 73 parturitions. The seasonal difference was significant on frequency of conceptions (χ2=10.16, p<0.02), but not significant on frequency of births (χ2=7.62, p>0.05). Twenty-nine infants were nursery-reared primarily due to inadequate maternal care (48%) or low birthweight (28%). Only one infant died under nursery-reared condition. These data provide useful information to sustain captive chimpanzee populations.

著者

寺本 研一 高瀬 浩造 寺岡 弘文 有井 滋樹 斉藤 佳子 田中 雄二郎

出版者

東京医科歯科大学

雑誌

基盤研究(B)

巻号頁・発行日

2001

---

1)ES細胞より肝細胞の分化誘導に関する研究前年度までの研究で、我々はマウスES細胞より胚様体細胞を経由してアルブミン産生細胞を分化させることに成功した。この細胞は尿素合成能、アンモニア分解能を持ち、肝細胞にきわめて近い細胞と考えられた。この細胞をC57BL/6マウスに肝障害の条件下細胞移植したところ生着し、アルブミンを産生した。しかしながら、同時に20-30%の頻度で奇形腫の発生をみた。今回、奇形腫発生を抑制するために、細胞のセレクションを行った。まず、胚様体細胞より単層細胞培養を行い15日目に分離し、パーコール法により比重で細胞をセレクションした。この細胞群はoct3/4の発現はネガティブであった。この細胞を上述の肝障害モデルマウスに移植したところ奇形腫の発生は認めなくなった。以上より、ES細胞より奇形腫の発生しない細胞群の回収が可能になった。また、さらにこの細胞群をFACS, MACSを使用し他の血球成分を除去することによりアルブミン陽性細胞を多く得ることが可能になった。また、これらの細胞は四塩化炭素による強い肝障害マウスにおいて凝固因子を有意に増加させることが判明した。2)カニクイザルES細胞ES細胞の臨床応用を目指して霊長類カニクイザルES細胞から肝細胞の分化誘導を試みた。霊長類ES細胞の分化誘導はマウスES細胞の分化誘導と異なる方法が必要であるが、我々の方法でアルブミン産生細胞を誘導することができた。3)血からの肝細胞の分化誘導我々は膀帯血からの肝細胞分化誘導に成功したが、アルブミンとCK-18、アルブミンとCK-19を発現する2種類の細胞を確認した。現在、胆管上皮細胞に分化誘導が可能かどうか研究中である。