Fido's Human Age Gets New Estimates
狗狗年齡計算新公式，教你正確判斷狗狗年齡！
How old is your four-legged best friend? Common wisdom says that a dog ages seven years for every human year. But Tina Wang, a graduate student at the University of California, San Diego, wanted a more accurate assessment. Her quest started five years ago, when she rescued a dog from a shelter.
你那四條腿的好朋友多大年紀了？常識告訴我們，狗活一歲相當於人類活七歲。但加州大學聖地牙哥分校的研究生蒂娜·王想要一個更準確的評估。她的探索始於五年前，當時她從收容所救出了一隻狗。
I kind of just wanted to ask how old she was because I felt like they were giving me an age that was very sensible, but I wasn't sure she was actually that old. So that kind of started this whole project.
「我只是想問確定狗狗多大了，因為我覺得他們給我的年齡雖然非常合理，但我不確定她真的有那麼大。因此，這就讓我開始了這一整個項目。」
Wang worked in Trey Ideker's lab, where they study changing patterns of DNA methylation in humans. Small chemical entities called methyl groups attach to stretches of DNA, which affects what sequences are active. As we age, some stretches of DNA get more methylated, and others less. The pattern is so consistent over the course of most people's lives that it can be used as an aging "clock." The same process happens in dogs -- and published reports existed from other labs about methylation patterns in dogs changing over time.
王在Trey Ideker的實驗室工作，該研究室研究人類DNA甲基化的變化模式。被稱為甲基的小化學物質附著在影響序列活躍度的DNA的延伸上。隨著年齡的增長，一些DNA片段的甲基化程度增加，而另一些片段的甲基化程度降低。這種模式在大多數人的一生中都是這般一致，以至於這種模式可以被視為一個老化的「時鐘」。同樣的過程也發生在狗身上，其他實驗室也發表過關於狗身上甲基化模式隨時間變化而變化的報告。
So Wang compared the age-related patterns in 320 humans and 104 Labrador retrievers.
因此，王比較了320個人和104隻拉布拉多尋回犬的年齡相關模式。
We knew that DNA methylation can predict age in many mammals, but we didn't know exactly how much of this was shared throughout the progression of life, and it wasn't clear if there was anything that was shared. And because of these similarities, we were able to identify a conserved aging signature that allows you to estimate dog years from human years based on this molecular profile.
「我們知道DNA甲基化可以預測許多哺乳動物的年齡，但我們不知道在整個生命進程中有多少是相通的，也不清楚是否存在這種相通。」由於這些相似之處，我們能夠識別出一個保守的老化特徵，這個老化特徵可以讓你根據這個分子結構來估計狗的壽命和人類的壽命。」
The researchers say that dog years per human year change over the lifetime of a dog. For example, their method has a one-year-old dog being the equivalent of a 30-year-old human. A four-year-old dog is about 52. And dog aging per year slows considerably after that.
研究人員表示，人的一歲相當於狗的幾歲會在狗的一生中會不斷變化。比如，他們的方法測出一隻一歲的狗相當於人類的30歲。一隻四歲的狗相當於人類的52歲。此後，狗每年的年齡增長速度明顯放緩。