- 學位論文
不同細胞質來源雜交牛在熱耐受能力之差異
Effects of cytoplasm origin on the thermal tolerance of hybrid cattle
摘要
目前已有研究指出，屬亞洲牛屬（Bos indicus, BI）之細胞質可改善歐洲牛屬（Bos taurus, BT）細胞核之耐熱能力，然而細胞質源自亞洲牛屬台灣黃牛之雜交荷蘭牛的抗熱能力是否優於純種荷蘭牛迄今未曾研究。於本研究中將首先利用PCR-RFLP技術鑑別本校畜牧場內所有牛隻之細胞質來源，並證實有4頭牛之粒線體 DNA源自BI牛屬之台灣黃牛，其後選取與此4頭雜交牛年齡及泌乳期相近之純種荷蘭牛作為試驗牛群。此4頭雜交牛之細胞質遺傳100%源自台灣黃牛，細胞核遺傳>96.9%（利用荷蘭牛精液配種5世代）源自荷蘭牛；純種荷蘭牛之細胞質遺傳與細胞核遺傳則均100%源自荷蘭牛，藉以探討不同細胞質來源牛種之抗熱能力差異。結果顯示，不論於涼季或熱季於每日07: 00、13: 00、19: 00所測得之肛溫均以細胞質源自台灣黃牛之雜交牛顯著（P < 0.05）低於純種荷蘭牛；而於01: 00之肛溫則於兩牛種間無顯著（P > 0.05）差異。而且，於熱季時細胞質源自台灣黃牛之雜交牛的平均每日乳產量（20.2 L/day）顯著（P < 0.05）高於純種荷蘭牛（17.9 L/day）；於涼季則兩牛種間之平均每日乳產量（27.4 vs. 26.3 L/day）無顯著（P > 0.05）差異，但兩牛種於涼季之乳產量均顯著（P < 0.05）高於熱季。此外，細胞質源自台灣黃牛之雜交牛的周邊血單核球細胞（Peripheral blood mononuclear, PBMC）經熱緊迫培養3 h後，其抑制細胞凋亡之基因包括HSP-27及HSP-90的mRNA相對表現量均顯著（P < 0.05）高於純種荷蘭牛之熱緊迫組；而促進細胞凋亡之蛋白質包括active-caspase-3、-8及-9蛋白質相對表現量，則反之以源自台灣黃牛雜交牛熱緊迫組顯著（P < 0.05）低於純種荷蘭牛之熱緊迫組，因此說明，耐熱之台灣黃牛的細胞質確實具有改善不耐熱荷蘭牛細胞核之耐熱能力，且此等能力可能源自於耐熱牛種之細胞質物質。
並列摘要
Recent studies indicated that utilizing the cytoplasm of Bos indicus （BI） is able to improve the thermotolerance of recombinant embryos containing nucleus derived from Bos taurus （BT）. Whereas, the thermotolerance from hybrid Holstein of cytoplasm which are originated from Taiwan native yellow cattle （Y; Bos indicus） whether superior to cytoplasm originated from Holstein （H; Bos taurus） not been explored. The currently study is going to be investigated the purity of Holstein cattle, analyzing the polymorphism of mitochondria-DNA （Mito-DNA） is used to identify the origin of cytoplasm, and we found cattle （n = 4） that Mito-DNA originated from Y has been confirmed; furthermore, choose cattle （n = 6） that similar of lactation and age are regarded as source of the cattle. The hybrid Holstein of Y-originated cytoplasm that cytoplasm heritability account 100%, nucleus heritability above 96.9% from Holstein（Inseminated with Holstein semen 5 generations）, hereby compared different cytoplasm origin on the heat-resistance of hybrid cattle. In the present study, no matter rectal temperature （RT） Y-originated cytoplasm of cool season or hot season were significantly （P < 0.05） lower than H-originated cytoplasm each time 7:00, 13:00 and 19:00 of the day; and have no difference（P > 0.05）between two breeds at 1:00. In addition, daily milk of Y-originated cytoplasm was significantly （P < 0.05） higher than those of H-originated cytoplasm in hot season. Furthermore, peripheral blood mononuclear cell （PBMC） derived from Y-originated cytoplasm after heat shock （42℃） with 3 hours, relative abundances of anti-apoptotic factors including Hsp-27, Hsp-90 mRNA in PBMC derived from Y-originated cytoplasm was significantly （P < 0.05） higher than those of PBMC derived from H-originated cytoplasm after heat shock; relative abundances of apoptotic promoting factors including caspase 3, 8, 9 in PBMC derived from Y-originated cytoplasm were significantly （P < 0.05） lower than those of PBMC derived from H-originated cytoplasm after heat shock. Taken together, cytoplasm originated from a thermotolerant breed （Taiwan native yellow cattle） is capable of improving cytoplasm originated from a thermosensitive breed （Holstein） on thermotolerance, this capability may due to inner substance from cytoplasm of thermotolerant cattle in breed.