日本研究人員在美國(guó)《國(guó)家科學(xué)院院刊》網(wǎng)絡(luò)版上報(bào)告說(shuō),，他們利用新開(kāi)發(fā)的冷凍保存技術(shù),，在虹鱒體內(nèi)培養(yǎng)出山女鱒的精子和卵子，并且利用這些精子和卵子繁殖出了山女鱒,。
研究小組帶頭人、東京海洋大學(xué)教授吉崎悟朗認(rèn)為,，這項(xiàng)“借腹生魚(yú)”技術(shù)有望使永久保存瀕危物種成為可能,。
東京海洋大學(xué)的研究人員向山女鱒的精巢注入保存液，然后用液氮冷凍,。約兩個(gè)月后解凍,，從中提取出能演變成精子的精原細(xì)胞，將其注入虹鱒幼魚(yú)的精巢和卵巢內(nèi),。之前,，這些剛出生不久的虹鱒經(jīng)過(guò)不育處理，無(wú)法生成精子和卵子,，且免疫功能尚未發(fā)育,，所以移植異種細(xì)胞后也不會(huì)出現(xiàn)排異反應(yīng)。
隨著虹鱒幼魚(yú)的生長(zhǎng),，雄虹鱒的精巢內(nèi)出現(xiàn)了山女鱒的精子,，雌虹鱒的卵巢內(nèi)出現(xiàn)了山女鱒的卵子。不過(guò)研究人員表示，本來(lái)應(yīng)該發(fā)育為精子的精原細(xì)胞如何發(fā)育成卵子的機(jī)制尚不清楚,。
研究人員對(duì)精子與卵子進(jìn)行人工授精,，成功繁育出了山女鱒。此外,，他們借助同樣的技術(shù),，用虹鱒和白點(diǎn)鮭的冷凍精巢，分別借對(duì)方之腹,，也取得了成功,。(生物谷Bioon.com)
doi: 10.1073/pnas.1218468110
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Generation of functional eggs and sperm from cryopreserved whole testes
Seungki Lee, Yoshiko Iwasaki, Shinya Shikina, and Goro Yoshizaki1
The conservation of endangered fish is of critical importance. Cryobanking could provide an effective backup measure for use in conjunction with the conservation of natural populations; however, methodology for cryopreservation of fish eggs and embryos has not yet been developed. The present study established a methodology capable of deriving functional eggs and sperm from frozen type A spermatogonia (ASGs). Whole testes taken from rainbow trout were slowly frozen in a cryomedium, and the viability of ASGs within these testes did not decrease over a 728-d freezing period. Frozen-thawed ASGs that were intraperitoneally transplanted into sterile triploid hatchlings migrated toward, and were incorporated into, recipient genital ridges. Transplantability of ASGs did not decrease after as much as 939 d of cryopreservation. Nearly half of triploid recipients produced functional eggs or sperm derived from the frozen ASGs and displayed high fecundity. Fertilization of resultant gametes resulted in the successful production of normal, frozen ASG-derived offspring. Feasibility and simplicity of this methodology will call for an immediate application for real conservation of endangered wild salmonids.
