原文標題：
Animal contraception
Don’t have kittens
A new vaccine suggests there’s more than one way to spay a cat
動物避孕
沒有小貓
一種新疫苗表明給貓絕育的方法不止一種

A new vaccine could be a cheap, simple solution to a big problem
一種新疫苗便宜又簡單，可以解決大問題

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RUNNING A CITY can be an expensive business. There are potholes to fix, policemen and firefighters to fund, and mountains of refuse to collect. In many cases, the kitty is empty.
管理城市可能是一件費錢費力的事情。如修復路面坑洼，資助警察和消防員，處理堆積如山的垃圾。在許多情況下，沒有預算來管理城市小貓。

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Other sorts of kitties cause problems, too.

其他小貓也會造成問題。

Some 480m of the world’s 600m domesticated cats are thought to be free-roaming.

據(jù)估計世界上有6億只家養(yǎng)貓，其中約有4.8億只是自由活動的。

Strays can be unsightly and can spread diseases, either to each other or to people. Many endure short and uncomfortable lives.

流浪貓可能長得不好看，它們之間可能會相互傳播疾病或傳染給人類。許多貓生活條件差且一生短暫。

Even those that land on their feet can cause suffering elsewhere—more than 60 species of animals, ranging from mice to birds, have been hunted to extinction by predatory cats.
即使貓咪脫離困境，它們也會造成其他方面的問題--從老鼠到鳥類，有 60 多種動物已被掠食性貓科動物獵殺至滅絕。

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Fixing the problem, as well as the cats, is not cheap.

解決貓相關的問題并不便宜。

Tel Aviv, which has tens of thousands of the animals, has spent over $100,000 a year on neutering programmes alone.

以色列的特拉維夫城擁有數(shù)萬只貓，每年僅在絕育計劃上就花費了10多萬美元。

Now, though, a paper in Nature Communications suggests a single jab could offer a cheap, safe and long-lasting way to sterilise a cat.
現(xiàn)在有個好消息，《自然通訊》上的一篇論文表明，單次注射是一種廉價、安全且持久的貓咪絕育方法。

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The technology involved is gene therapy, in which a gene is carried into an organism’s body, usually by a modified virus, in order to fulfil some additional function.

所涉及的技術是基因療法，一般是通過改造病毒將基因攜帶到生物體內，以產生一些額外的作用。

This has been gaining momentum in humans, with seven different gene therapies approved by America’s Food and Drug Administration as of this February.

基因療法在人類中蓬勃發(fā)展，截至今年2月，美國食品和藥物管理局已經批準了7種不同的基因療法。

Most are designed to target rare genetic diseases, including haemophilia B, where mutation causes problems with blood clotting.
大多數(shù)是針對罕見的遺傳疾病，包括血友病B，因基因突變導致血液凝固問題。

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David Pépin, a molecular biologist at Harvard University, came to realise the same techniques could also be used to induce contraception.

哈佛大學的分子生物學家大衛(wèi).佩平意識到，同樣的技術也可以用于避孕。

His laboratory was investigating a lesser-known reproductive hormone called AMH (anti-müllerian hormone), which is produced by the follicles that house immature egg cells in mammals.

他的實驗室正在研究一種鮮為人知的生殖激素，稱為AMH（抗繆勒管激素），這種激素是由哺乳動物體內未成熟卵細胞的卵泡產生的。

These follicles grow inside the ovaries until they burst, releasing their cargo into the fallopian tubes and towards potential fertilisation.

卵泡在卵巢內長大，直至破裂，然后把其中的物質釋放到輸卵管中并進行潛在的受精。

More mature follicles produce AMH in order to slow down the growth of those eggs remaining in the ovaries.

更成熟的卵泡產生AMH，以減緩留在卵巢中卵子的生長速度。

The hormone acts as a red traffic light, as it were, to ensure the flow of maturing eggs is not too rapid.
這種激素就像一個紅色交通燈，以確保成熟卵子的流動不會太快。

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Dr Pépin concluded that persuading a mammal to produce higher-than-usual amounts of AMH—by inserting the right type of gene—might strengthen this braking signal and halt follicle production altogether.

佩平博士得出結論，通過植入正確的基因，說服哺乳動物產生高于正常量的AMH，可能會加強這種抑制信號并完全停止卵泡的生產。

After initial successes in rodents, he joined forces with Bill Swanson at the Cincinnati Zoo and Botanical Gardens to test the idea on cats.
在嚙齒動物身上取得初步成功后，他與辛辛那提動植物園的比爾.斯旺森聯(lián)手合作，在貓身上做實驗。

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In 2019 the researchers injected six cats with a harmless virus that contained a synthetic copy of a feline AMH gene, and three control cats with the virus alone.
2019年，研究人員給6只貓注射了一種無害病毒，該病毒含有貓科動物 AMH 基因的合成物質，并給3只對照貓只注射了無此基因的病毒。

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All nine cats—which were named after the wives of American presidents—then had their faeces monitored over the course of two years so that the levels of their reproductive hormones could be checked.
所有9只貓--均以美國總統(tǒng)夫人的名字命名--然后在2年內對它們的糞便進行監(jiān)測，以便了解它們的生殖激素的水平。

In order to ensure the right cats were being matched to the right scat, each was fed food with a different coloured dye or, for a few fabulous individuals, glitter.
為了確保貓與糞便匹配無誤，研究人員給每只貓都喂食了不同顏色的染料，或者給少數(shù)獨特貓咪喂食了發(fā)光物。

After eight months, and then again after 20 months, male cats were introduced into the living quarters so that the females’ breeding patterns could be assessed.8個月后，重復操作，又過了20個月，將公貓引入實驗生活區(qū)，以便評估母貓的繁殖情況。
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Though the three control cats (Michelle, Nancy and Rosalyn) ovulated and got pregnant, the six injected with the gene-carrying virus (Betty, Dolly, Jacqueline, Abigail, Barbara and Mary) did not.
盡管3只對照組的貓（米歇爾、南希和羅莎琳）成功排卵并懷孕，但注射了攜帶基因病毒的6只貓（貝蒂、多莉、杰奎琳、阿比蓋爾、芭芭拉和瑪麗）沒有排卵和懷孕。

Each had levels of AMH up to a thousand times higher than before they were treated. Four refused to even try to breed, and the two that were still receptive to the idea had no pregnancies.
每只貓的AMH水平都比實驗前高出1000倍。有4只貓甚至拒絕交配繁衍，而另外2只交配的貓也沒有懷孕。

“These cats are not able to reproduce,” concludes Dr Swanson.
斯旺森博士總結道："這些貓無法繁衍后代。"

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While the precise mechanisms in cats and rodents are not identical, high levels of AMH seem to have a contraceptive effect in both species.
雖然貓和嚙齒動物的機體運作機制不相同，但高水平的AMH似乎對這兩個物種都有避孕作用。

Dr Pépin hopes AMH could become a useful target in human contraception too—though as a pill with temporary effects rather than a permanent injection.
佩平博士希望AMH也能成為人類避孕的有用方法--盡管人類需要的是一種具有臨時避孕效果的藥片，而不是永久效果的注射劑。

Presently, the most common kind of hormonal contraception is the combined pill, which contains oestrogen and progesterone.
目前，最常見的激素避孕藥是混合型避孕藥，它含有雌激素和孕激素。

These limit the release of hormones which cause follicles to ripen, and thicken the mucus at the entrance of the womb, preventing the passage of sperm.
激素使卵泡成熟，避孕藥就是限制這種激素的釋放，并使子宮入口處的粘液變稠，阻止精子通過。

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But there are oestrogen and progesterone receptors all over the body, not just in the reproductive system. Synthetic hormones affect those as well.
但全身都有雌激素和孕激素受體，不只是生殖系統(tǒng)才有。合成荷爾蒙也會影響全身受體。

That is one reason for the pill’s many side-effects, including mood swings, nausea and headaches.
這是避孕藥產生許多副作用的原因之一，包括情緒波動、惡心和頭痛。

AMH receptors in humans are much more specific, being found mostly in the reproductive system.
人類的 AMH 受體更具特異性，主要存在于生殖系統(tǒng)中。

The hope is that a contraceptive that targets AMH may therefore be one with many fewer side-effects.
因此，但愿AMH避孕藥的副作用更少。

（恭喜讀完，本篇英語詞匯量886左右，有刪減）
原文出自：2023年6月17日《The Economist》Science & technology版塊

精讀筆記來源于：自由英語之路

本文翻譯整理: Irene本文編輯校對: Irene
僅供個人英語學習交流使用。

【補充資料】（來自于網絡）
特拉維夫Tel Aviv是以色列的第二大城市，位于地中海沿岸的特拉維夫都會區(qū)。它被譽為中東的“城市春天”和“白色城市”，因其現(xiàn)代化的建筑、開放的文化和豐富的夜生活而聞名。擁有許多藝術家、設計師和企業(yè)家。這里有許多時尚的藝術畫廊、音樂會和戲劇表演，還有世界級的博物館和美術館。該市還擁有美麗的海灘，是許多人在夏天度假的熱門目的地。這里也是水上運動愛好者的天堂，可以盡情享受沖浪、風帆和潛水等活動。這座城市是創(chuàng)新和科技的先驅，在高科技和創(chuàng)業(yè)領域具有重要地位。

抗繆勒管激素AMH（Anti-Müllerian Hormone）是一種由卵巢產生的激素。它在女性身體中的主要作用是抑制卵泡的發(fā)育和成熟。AMH的測量可以幫助醫(yī)生評估女性的卵子儲備量和卵巢功能。通過檢測AMH水平，醫(yī)生可以判斷女性的生殖年齡和卵子的數(shù)量，從而幫助預測她們的生育能力和卵子的質量。AMH的測量也常用于輔助不孕癥的診斷和治療。對于無法自然懷孕的女性，AMH的水平可以幫助醫(yī)生決定最適合的生育輔助技術，如試管嬰兒或卵巢刺激治療。此外，AMH的測量還可以用于評估多囊卵巢綜合征（PCOS）和卵巢早衰等與卵巢功能相關的疾病。PCOS是一種常見的女性生殖系統(tǒng)疾病，會導致卵巢多囊、排卵障礙和激素失調。AMH的水平在PCOS患者中通常較高。

【重點句子】（3個）
Strays can be unsightly and can spread diseases, either to each other or to people. Many endure short and uncomfortable lives.
流浪貓可能長得不好看，它們之間可能會相互傳播疾病或傳染給人類。許多貓生活條件差且一生短暫。

The hormone acts as a red traffic light, as it were, to ensure the flow of maturing eggs is not too rapid.?這種激素就像一個紅色交通燈，以確保成熟卵子的流動不會太快。

While the precise mechanisms in cats and rodents are not identical, high levels of AMH seem to have a contraceptive effect in both species.
雖然貓和嚙齒動物的機體運作機制不相同，但高水平的AMH似乎對這兩個物種都有避孕作用。