Fifty
(or More) Shades of Gray: Gene for Graying Hair Identified
VOA News
Last updated on: February 25, 2016 5:00 PM (source)
Fifty (or More)
Shades of Gray: Gene for Graying Hair Identified
揭開白髮的五十道陰影:科學家找到白頭髮基因
Reuters
March 02, 2016 6:08 PM
WASHINGTON—
They may not have settled
the enduring debate over whether gray hair makes a person look distinguished or just plain old, but
scientists have identified for the first time a gene behind graying
hair.
Researchers said Tuesday an analysis of DNA from more than 6,300 people
from five Latin American countries enabled them to pinpoint a gene that affects a
person's likelihood of getting gray hair.
The gene, called IRF4, is involved in regulating melanin, the pigment responsible for hair color
as well as the color of the skin and eyes.
People with a certain version of the gene are predisposed to graying hair,
according to University College London human geneticist Andres
Ruiz-Linares, one of the researchers in the study published in the
journal Nature Communications. The researchers said hair graying is not
driven exclusively by
genetics, with other factors in the mix such as stress or experiencing
a traumatic event.
"This is really the first study on the genetics of hair graying in
humans," said Kaustubh Adhikari, University College London statistical
geneticist.
Road to
reversal
People spend a lot of time and money dyeing gray hair back to their
natural hair color. The researchers said identifying this gene could
offer a path forward for developing a treatment that could prevent or
reverse graying.
"A drug that has effects on the melanin-production pathway in hair follicles as the follicles develop
internally might reduce the need to apply external hair dyes on the
scalp hair after it comes out. This is certainly a research avenue worth pursuing," Kaustubh
said.
The researchers combed through genetic information from men and women
in Brazil, Colombia, Chile, Mexico and Peru, with a combination of
European, Native American and African ancestry.
The gene variant predisposing people to early hair graying was
essentially only seen in those of European ancestry. "This might, to
some extent, explain why hair graying is more common in Europeans than
in other populations," Ruiz-Linares said.
One of the researchers brushed aside
the issue of whether or not gray hair is attractive.
"Personally I don't have much of a view regarding the social response
to hair graying, but I find it an interesting model to study aging in
general," said Desmond Tobin, a hair follicle and pigmentation
biologist at Britain's University of Bradford.
The study also identified genes related to other hair traits including
curliness, beard thickness, eyebrow thickness and predisposition for
eyebrows that join together, known as unibrow or monobrow.
白頭髮是讓人看起來顯得尊貴(distinguished),抑或只是單純顯老,科學家雖還沒能替這個長久以來的爭辯下斷語(settle the debate over . . .),但卻是第一次找到了頭髮變白背後的基因。
研究人員於週二表示,分析了超過6300位來自於五個拉丁美洲國家的人的DNA後,他們已能精確指出(pinpoint)會影響頭髮變白的可能性的基因。
這個稱為IRF4的基因牽涉到黑色素(melanin)的調節。黑色素是負責頭髮、皮膚和眼睛顏色的色素(pigment)。
此研究發表於期刊《自然通訊》(Nature
Communications),倫敦大學學院人類遺傳學家(geneticist)安德烈斯‧魯伊斯利納雷斯(Andres Ruiz-Linares)是研究人員之一,根據他的說法,此基因的某一型讓人體質上很容易(be
predisposed to . . .)長白頭髮。研究人員表示,長白頭髮不單單只是(not
exclusively)由基因所驅使,還有如壓力或經歷創傷(traumatic)事件等其他因素混合其中。
倫敦大學學院的統計遺傳學家(statistical geneticist)卡斯圖‧阿迪卡里(Kaustubh
Adhikari)表示:「這的確是第一個對於人類白髮基因的研究。」
逆轉之道
人們會花很多時間和金錢把白髮染回他們天生的髮色。研究人員表示,指認出這個基因開啟了一個繼續發展的道路,可以開發預防白髮或逆轉頭髮發白的療法(treatment)。
卡斯圖說:「藥物在毛囊(hair follicle)於(頭皮)內部成長時,會對毛囊的黑色素生產過程產生影響,因此當頭髮長出來後,從外部塗抹(apply)在頭皮(scalp)上的染劑的需求就會減少。這確實是一個值得再深入的研究途徑(research
avenue)。」
研究人員仔細地檢查(comb through . . .)過巴西、哥倫比亞、智利、墨西哥和秘魯的男性和女性身上的基因遺傳訊息(genetic
information),其中混有歐洲、美洲原住民和非洲的血統(ancestry)。
基本上只有在具歐洲血統的人身上發現這個誘發頭髮提早發白的基因的變異型(variant)。
研究人員安德烈斯‧魯伊斯利納雷斯表示:「在某種程度上(to some
extent),這可以解釋為什麼長白頭髮在歐洲人身上比其他族群還來得普遍。」
其中一位研究人員「撇開」(brush aside . . .)了白頭髮是否具有吸引力的這個議題。
(編按:“brush” 當動詞有「整理頭髮」、「梳頭髮」的意思。作者有意在此篇與頭髮有關的新聞中選用 “brush aside”這個片語來表示「不管」或「不理睬」,故在此譯作「撇開」。)
「對於(regarding)社會大眾對白頭髮的反應,我個人沒什麼太多看法,但大致上,我覺得這是一個有趣的研究老化的模型。」英國布拉德福德大學研究毛囊及色素的生物學家德斯蒙‧德
托賓(Desmond Tobin)如此表示。
這個研究也發現與其他毛髮特性(trait)有關的基因,這些特性包括了捲曲度、鬍子和眉毛濃密度,以及可能會讓眉毛連在一起,稱為「連心眉」(unibrow or monobrow)的傾向。
(編按: uni-跟mono-這兩個字首都是「單一」的意思, “unibrow” 和“monobrow”就是指左右兩邊眉毛長在一起,看起來成一道「單一的眉毛」。)
編後記:
英文的「灰色」可以拼成gray或grey。自然長出的「白頭髮」在英文裡是用 “gray/grey hair”一詞。 “white hair"(白色的頭髮)則指特意染白的或本來就是白色的頭髮(如巫師的白髮),或是動物的白色皮毛。
在我們的文化裡,長白頭髮大多時候只跟「老化」或「操勞」的意象有關,比較偏正面的聯想也許會與長者的「智慧」或「慈愛」作連結。歐美人士天生的髮色本來就比較多種,或許頭髮發白在視覺觀感上本身就不會太過強烈,還有可能會被視為是一種「造型」,帶給人不同的感覺。以美國來說,許多男星過了中年會開始長白頭髮,但許多人覺得頂著一頭灰白頭髮的男星反而更有特殊魅力,具有一種「尊貴感(distinguished)」,男星喬治‧克隆尼(George Clooney)即是常被人認為是長了白頭髮而更有魅力的一例。但這個看法還是見仁見智的,因此本新聞作者才會說這是一個「爭論不休的話題(enduring debate)」。
本新聞標題 “Fifty (or More) Shades of Gray” 如果單就字面與新聞內容來解讀其意義的話,應可譯作「白頭髮的五十種(或更多種)色調(shade)」。但這個新聞標題是有意仿造情愛小說《格雷的五十道陰影》(Fifty Shades of Grey) 的文字遊戲。小說標題中的 “Grey” 不是灰色,而是男主角的姓氏,格雷(Grey),有著其不為人知的情慾世界,形象上神秘而性感,危險又誘人,像是讓人看不透但又想一探究竟的秘密。新聞作者套用了這個小說標題,把格雷(Grey)這個姓氏與英語中形容白頭髮的灰色作結合,除了單純文字上的趣味之外,也帶出科學家們試圖解讀出基因的遺傳訊息,發現白頭髮的秘密,還有白頭髮難以捉模的魅力等這些可能的解讀。
Language Notes
distinguished
(a) 高貴的,高雅的
pinpoint
(v) 準確地確定(位置,範圍,性質,程度等)
pigment
(n) 色素
predisposed
(a) 具有……的傾向
本義是「具有某種傾向」,後接介詞 “to”;常用來指人的身體或建康上具有某種傾向,語意與中文「體質」相近,其名詞為predisposition。
exclusively
(ad) 專門地;專有地
traumatic
(a) 外傷的;(造成心理)創傷的
follicle
(n) 小囊;卵泡;濾泡
avenue
(n) 途徑,方法 *本字常用的意思為「大街,大道」
ancestry
(n) 世系,血統 *ancestor (n) 祖先
brush
aside (v phr) 漠視;棄……於一旁
Check your vocabulary!
Fill
in the blanks with a word or phrase from the list above. Make necessary
changes. After you finish, highlight the blanks to reveal the hidden
answers.
1. Rescue teams have now pinpointed the location of the ship.
2. His son's death was the most traumatic
event in Stan's life.
3. The office staff are almost exclusively
female.
4. Melanin is the dark brown pigment
of the hair, skin and eyes.
5. Her mother is of German ancestry.
編譯:簡嘉呈
|