Obese Dad's Sperm May Influence Offspring's Weight

Just below the Arctic Circle[北极圈] in northern Sweden[瑞典北部] sits a town called Överkalix[上卡利克斯市]. It’s home to only about a thousand people. But those inhabitants[居民] were the subjects of a seminal study[开创性研究] in human genetics[人类遗传学]: the research suggested that what our parents, or even grandparents ate—if they grew up during feast or famine[时富时贫/饱一顿饿一顿]—could actually affect our risk of heart disease[心脏病] and diabetes[糖尿病].

"It shows that either caloric restriction[热量限制;限制饮食;饮食受限] or excess of food[过度饮食], can send, depending on the window of your own development, a similar message to the next generation." Romain Barres, a molecular biologist[分子生物学家] at the University of Copenhagen[哥本哈根大学].

That trans-generational[跨代] message is sent, of course, through sperm and eggs[精卵]. So Barres and his colleagues compared the sperm of 13 lean[瘦的] versus 10 obese[肥胖的] men. And they found that the heavyweights[重量级的] had epigenetic changes[表观遗传变异] to their sperm—meaning additional chemical groups[化学基团;化学群] on their DNA that affect how genes are expressed. And many of those changes were to sequences[序列] known to affect brain development—including genes[基因] that regulate appetite[调节食欲].

表观遗传现象是指基因表达发生改变但不涉及DNA序列的变化， 能够在代与代之间传递。

But the changes were not permanent[永久的]. Because when the researchers studied the sperm of men who underwent weight loss surgery[瘦身手术], they found that many of those genetic alterations[遗传变异] reversed[颠倒;翻转] post-surgery[手术后], especially the ones in areas related to appetite control[食欲控制]. The study is in the journal Cell Metabolism[细胞代谢].

The big question now is how much these epigenetic changes[表观遗传变异] actually influence the next generation. Barres is now comparing fathers' sperm to the cord blood[脐带血] of their babies, to find out. But the finding suggests a mechanism[ 机制；原理] by which our actions, our eating habits, our fitness, can affect our children. Which might make you wonder: what should you be eating?

"And how long should you be doing pushups[伏地挺身；俯卧撑] before you conceive[怀孕] your child? It's a long road before what we know is optimal for[最优的] our children."

And what may seem optimal today—like partaking[分享；参与；分担] of holiday feasting[节日盛宴]—may come back to haunt[给……带来困扰] your children's children, like the ghost of Christmas past.

—Christopher Intagliata

From 60-Second Science