After all, the genes that make up our DNA contain all the information about who we are.

畢竟，構成 DNA 的基因包含了我們的所有資訊。

They give instructions to the body cells and determine everything from the color of our eyes to the functioning of our lungs and our propensity for diseases such as cancer or diabetes. But the life one leads, along with other factors, makes it more complex.

它們向身體細胞發出指令，決定著從眼睛的顏色到肺部功能以及癌症或糖尿病等疾病的傾向等一切。但是，一個人的生活以及其他因素使其變得更加複雜。

Imagine two identical twin brothers.

想象一下兩個同卵雙胞胎兄弟。

Their DNA is the same, but the way they live is very different.

它們的 DNA 是相同的，但生活方式卻截然不同。

One leads a calm life, the other has a stressful job.

一個生活平靜，一個工作緊張。

One exercises more, but the other eats better.

一個人運動得更多，但另一個人吃得更好。

The twins start to acquire different characteristics or perhaps develop different diseases.

雙胞胎開始獲得不同的特徵，或者可能患上不同的疾病。

How can this be if their genome is exactly the same? The reason is that the human body has a natural way of turning some of our genes on or off in response to the environment and the lifestyle we lead, and it does so without modifying the DNA.

如果他們的基因組完全相同，這怎麼可能呢？原因是人體有一種自然的方式，可以根據環境和生活方式開啟或關閉我們的某些基因，而且無需修改 DNA。

It's called epigenetics, and the set of chemicals that mark the genome and tell cells what to do is known as the epigenome. Think of DNA as an instruction manual for how the cell should work.

這就是所謂的表觀遺傳學，而標記基因組並告訴細胞該怎麼做的一系列化學物質被稱為表觀基因組。把 DNA 想象成細胞如何工作的說明書。

Every cell in your body has one of these manuals.

你體內的每個細胞都有一本這樣的手冊。

The epigenome is like someone picking up a pack of colored markers to emphasize or cross out different parts of the manual.

表觀基因組就像有人拿起一包彩色記號筆，強調或劃掉手冊中的不同部分。

This part here, it's more important, accentuate it.

這部分更重要，要突出它。

This one, don't use it. And how does it do it?

這個，別用。它是怎麼做到的？

Every cell in your body contains almost two meters of DNA.

人體內的每個細胞都含有近兩米長的 DNA。

In order for it to fit inside a cell, the genetic material is wrapped up in a set of proteins called histones to form a compact structure.

為了使遺傳物質能夠在細胞內存活，遺傳物質被一組名為組蛋白的蛋白質包裹起來，形成一個緊湊的結構。

But that means the cell doesn't always have easy access to the genes.

但這意味著細胞並不總能輕易獲得基因。

This is where epigenetics comes into play.

這就是表觀遺傳學發揮作用的地方。

Epigenetic marks are chemical markers that act on the structure to give it instructions to compress or decompress the DNA. If they compress it, the cell cannot access the information and the gene is turned off.

表觀遺傳標記是一種化學標記，作用於結構，向其發出壓縮或解壓縮 DNA 的指令。如果壓縮，細胞就無法獲取信息，基因就會被關閉。

Epigenetic marks that decompress the DNA allow the cell to read the gene and turn it on.

解壓縮 DNA 的表觀遺傳標記允許細胞讀取基因並將其激活。

This process starts as soon as the first cells of the human embryo begin to divide.

當人類胚胎的第一批細胞開始分裂時，這一過程就開始了。

That is why it is so important for the baby what its mother eats, her emotional and physical state, plus the medicines and vitamins she takes.

是以，母親的飲食、情緒和身體狀況，以及服用的藥物和維生素，對嬰兒都非常重要。

All that information can be transmitted in the form of chemical signals to the baby through the blood.

所有這些資訊都可以通過血液以化學信號的形式傳遞給寶寶。

If the mother's diet during pregnancy is poor, the baby could be more prone to obesity since its epigenome has programmed it to store more calories every time it eats.

如果母親在懷孕期間飲食不當，胎兒可能更容易肥胖，因為胎兒的表觀基因組會在每次進食時儲存更多的熱量。

This phenomenon has been tested in several studies with women who went through periods of prolonged famine during wars, for example. But the role of the father is also important because he can transmit some of his epigenetic marks to its children.

例如，在對經歷過戰爭期間長期饑荒的婦女進行的多項研究中，對這一現象進行了檢驗。但父親的作用也很重要，因為他可以將自己的一些表觀遺傳標記傳遞給子女。

For example, if a father has been smoking heavily since adolescence, this may result in a shorter life expectancy for his children and even for his grandchildren.

例如，如果父親從青春期開始就大量吸菸，這可能會導致其子女甚至孫輩的預期壽命縮短。

The epigenome acts on our body throughout our lives, not just in the embryonic phase.

表觀基因組對人體的影響貫穿我們的一生，而不僅僅是在胚胎階段。

As in the example of the twins, our habits, our diet, our experiences, and the environment in which we live can turn our genes on or off. But it goes further.

正如雙胞胎的例子一樣，我們的生活習慣、飲食、經歷和生活環境都可以開啟或關閉我們的基因。但這還不止於此。

Epigenetics shows that nature may have found a way to pass on trauma to subsequent generations.

表觀遺傳學表明，大自然可能已經找到了將創傷遺傳給後代的方法。

In one experiment, scientists made male mice associate the smell of cherry blossom with pain caused by an electric shock.

在一項實驗中，科學家讓雄性小鼠將櫻花的氣味與電擊造成的疼痛聯繫起來。

These mice procreated, and their offspring also became nervous when they were presented with that smell, despite not having had contact with their parents during their upbringing.

這些小鼠繁殖後代時，儘管它們在成長過程中沒有與父母接觸過，但當它們聞到這種氣味時也會變得緊張。

The third generation of mice, the grandchildren of the first, also showed greater sensitivity to that smell, more than any of the others. In their DNA, the scientists found epigenetic marks on a gene responsible for coding a protein that is a receptor for odors.

第三代小鼠是第一代小鼠的孫子，它們對這種氣味的敏感性也比其他小鼠更高。在它們的 DNA 中，科學家們發現了一種負責編碼氣味受體蛋白質的基因上的表觀遺傳標記。

They also had more neurons in their brains responsible for detecting the smell of cherry blossom.

他們的大腦中負責檢測櫻花氣味的神經元也更多。

But that does not mean that we are predestined to relive the emotions of our parents and grandparents.

但這並不意味著我們註定要重溫父母和祖父母的情感。

Scientists are still studying how this type of epigenetic transmission of trauma can occur in humans.

科學家們仍在研究這種創傷的表觀遺傳傳遞是如何在人類身上發生的。

Even so, they already predict that it might be possible to reprogram this same mechanism to make us healthier since epigenetic changes are reversible.

即便如此，他們已經預測，由於表觀遺傳變化是可逆的，是以有可能對這一機制進行重新編程，使我們更加健康。

This opens up a huge universe of possibilities in the scientific world. For example, there are studies to create drugs that make it possible to reverse the epigenome markers that favor the appearance of certain tumors.

這為科學界帶來了巨大的可能性。例如，目前正在研究如何製造藥物，以逆轉有利於某些腫瘤出現的表觀基因組標記。

Epigenetics could also revolutionize the treatment of different diseases, such as diabetes, lupus, Alzheimer's, or even some addictions.

表觀遺傳學還能徹底改變不同疾病的治療方法，如糖尿病、紅斑狼瘡、老年痴呆症，甚至一些成癮症。

The big challenge now is how to develop drugs that act only on the negative markers without impacting the positive markers. Epigenetics proves that not everything is written in our genes and that we can positively influence our genome.

現在最大的挑戰是如何開發只作用於負面標記而不影響正面標記的藥物。表觀遺傳學證明，並非所有東西都寫在我們的基因裡，我們可以積極地影響我們的基因組。

Something that can not only benefit us in the present but also our future generations.

這不僅能造福我們當代人，也能造福我們的子孫後代。