著者

海老原 充 榊田 星史 泉 徳和

出版者

石川県立大学

雑誌

石川県立大学年報 : 生産・環境・食品 : バイオテクノロジーを基礎として (ISSN:18819605)

巻号頁・発行日

vol.19, pp.23-30, 2008-03-31

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環境問題の影響は、人間生活のみならず多くの動植物にも及び、様々な動植物種が絶滅の危機に瀕している。2003年に絶滅した日本産のトキをはじめとして、鳥類も例外ではない。こういった絶滅危惧種、あるいは生物資源の維持にためには、性的単一形が多く見られる鳥類の性別鑑別技術が欠かせない。本研究では、これまで鳥種別の条件にて行われることが多かったダチョウ、エミュー、ヒクイドリ、レアなどの走鳥類(平胸類)の雌雄鑑別を同一の条件で行える技術を確立するとともに、より簡便な羽軸からの安定したDNA調製を試みた。ダチョウ4個体、エミュー44個体、ヒクイドリ5個体、レア4個体、合計57個体から羽軸を採取しDNAを調製後、PCRによる雌雄鑑別を行ったところ、50個体において可能であった。雌雄鑑別が困難であった7個体中5個体は、同一個体の異なる羽軸を用いて再度DNAを調製することで雌雄鑑別が可能であった。さらに、雌雄鑑別に用いた性染色体特異配列kWl由来のPCR増幅物は、ヒクイドリ科に属するヒクイドリとエミューにおいてのみ、Z染色体上で重複が起きていることが観察された。これにより、ヒクイドリ科に属するヒクイドリとエミューのkW1配列は、系統分類上、ダチョウ科やレア科と分岐したのちに重複が起きたこと、さらに鳥類の性決定はZ染色体の発現量の影響を受けることから、性決定候補遺伝子探索のマーカーになる可能性が示唆された。

著者

小野 守 小関 茂樹 斉藤 康倫 泉 徳和 松井 基純 大澤 健司 三宅 陽一

出版者

日本獸医師会

雑誌

日本獣医師会雑誌 = Journal of the Japan Veterinary Medical Association (ISSN:04466454)

巻号頁・発行日

vol.61, no.10, pp.780-783, 2008-10-20

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人工授精(AI)後の陰唇刺激がホルスタイン種乳用牛の受胎率に及ぼす効果を評価するために、未経産牛295頭を用い、AI直後に手指による陰唇刺激を15秒間行って対照群と比較した。その結果、陰唇刺激群の受胎率は対照群よりも高かった(69.2% vs 64.7%)が、有意差はなかった。また、対照群において7月から8月に受胎率が低下する傾向が認められたが、陰唇刺激群では認められなかった。両群の受胎成績のTemperature-Humidity Index (THI)別の分析では、対照群において、暑熱ストレス条件下とされるTHIが72以上の場合の受胎率は、72以下の場合よりも有意に低かった(P<0.01)が、陰唇刺激群ではそのような差異は認められなかった。

著者

泉 徳和

出版者

石川県農業短期大学

雑誌

石川県農業短期大学特別研究報告 (ISSN:03899985)

巻号頁・発行日

vol.9, pp.a-85, 1980-12-25

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The mechanism of ejaculatory reflexes is characteristic in bulls as reported by previous workers. Wilcox and coworkers reported that about 10% of the culled bulls were due to the difficulty of semen collection. For the resolution of the problem and to improve the efficiency of semen collection, the mechanisms of ejaculatory reflexes in this species should be clarified neuro-anatomically. At the present study the effects of auditory, olfactory and visual stimuli concerned with the cerebral cortex on the sexual drive and on the ejaculatory reflex were systematically investigated. Then, a location where the terminal nerve receptors involved in ejaculation existed was peripherally demonstrated. Furthermore a silver impregnation method was devised to stain the peripheral nerves of the bull penis. With this method, the author made clear the sensory nerve endings, the nerve supply and the nerve development of the bull penis. The results are summarized as follows. I. Studies on the effects of stimuli concerned with the cerebral cortex on the mechanisms of ejaculatory reflexes. 1. Auditory stimuli from the specific calls of cow significantly reduced sexual reaction time (P <0.01), but these were not effective for the semen characteristics. 2. Auditory stimuli from the noises of tractor (about 85 phon) significantly inhibited the sexual reaction (P <0.05), but these were not effective for the semen characteristics. 3. Auditory stimuli from shouting caused delay in sexual reaction time (P <0.01). However in some cases these auditory stimuli reduced the reaction time for the first ejaculation (P <0.01). 4. The olfactory stimuli from the mucus or urine of the estrous cow elicited sexual drive in some bulls, but did not in most other bulls. 5. The mucus of the estrous cow reduced sexual reaction time in some bulls, but did not in the majority of the bulls. 6. It was demonstrated that visual stimuli were highly effective for a sexual reaction including ejaculation. The relationship between sexual reaction time and semen characteristics is analyzed and classified to the following three types. 1) Type I : Bulls showing significant positive correlation between both parameters, i.e., a longer reaction time resulted in larger volume of semen. This type of bulls was most popular. 2) Type II : Bulls showing no significant correlation between both parameters, i.e., semen volume was not influenced by the reaction time. 3) Type III : Bulls showing negatively significant correlation between both parameters, i.e., a longer reaction time resulted in smaller volume of semen and inferior semen quality. This type of bulls was more sensitive especially to the visual stimuli than other type of bulls. Excessive visual stimuli to these bulls by restraining or false mounting were not favorable at the semen collection barn, because they had already been in the sexual preparatory process on the way to the collection barn from their pens. II. Studies on the localization of the sensory nerve endings which induce ejaculation. 1. The galea glandis of the bull did not contact with anything during masturbation, but a bull usually rubbed his erected penis with his dewlap at the portion of the collum glandis or at the more proximal part of the penis. This suggests that the sensory nerve endings locate at the collum glandis. 2. When a massage on the galea glandis or on the prepenile sheath was applied the bull did not cause ejaculation. The semen was obtained by massaging the collum glandis, but in this case, the massage might have been applied simultaneously on the penile sheath. 3. Ejaculation did not occur when the inner temperature of artificial vagina was at 18℃, but the semen was successfully obtained at 40℃. This suggests that the temperature also plays an important role on eliciting ejaculation. 4. Anesthesia on the surface of galea glandis with Lidocaine did not block the ejaculatory reflex. On the other hand, ejaculation did not occur when this case