备注请放最后面 违者新闻文章删除
1.媒体来源:
外媒 sciencealert
2.记者署名:
Jenny Graves, The Conversation
3.完整新闻标题:
The Y Chromosome Is Slowly Vanishing. A New Sex Gene May Be The Future of Men.
男性末日！哺乳动物有灭绝Y染色体的趋势!
4.完整新闻内文:
The Y Chromosome Is Slowly Vanishing. A New Sex Gene May Be The Future of Men.
Humans
23 August 2024
By Jenny Graves, The Conversation
Mans Eye Staring Close Up
(Dmitry Bayer/Getty Images)
The sex of human and other mammal babies is decided by a male-determining
gene on the Y chromosome. But the human Y chromosome is degenerating and may
disappear in a few million years, leading to our extinction unless we evolve
a new sex gene.
The good news is two branches of rodents have already lost their Y chromosome
and have lived to tell the tale.
人类
2024 年 8 月 23 日
经过珍妮·格雷夫斯《对话》
男人的眼睛凝视特写
（德米特里·拜尔/盖蒂图片社）
人类和其他哺乳动物婴儿的性别是由 Y 染色体上的男性决定基因决定的。但人类的Y 染
色体正在退化，可能会在几百万年后消失，除非我们进化出新的性基因，否则就会导致我
们的灭绝。
好消息是，囓齿类动物的两个分支已经失去了 Y 染色体，并且还活着讲述了这个故事。
A 2022 paper in Proceedings of the National Academy of Science shows how the
spiny rat has evolved a new male-determining gene.
How the Y chromosome determines human sex
In humans, as in other mammals, females have two X chromosomes and males have
a single X and a puny little chromosome called Y. The names have nothing to
do with their shape; the X stood for 'unknown'.
2022 年《美国国家科学院院刊》上的一篇论文展示了刺鼠如何演化出一种新的雄性决定
基因。
Y染色体如何决定人类性别
人类和其他哺乳动物一样，雌性有两条 X 染色体，雄性有一条 X 染色体和一条称为 Y
的微小染色体。 X代表“未知”。
The X contains about 900 genes that do all sorts of jobs unrelated to sex.
But the Y contains few genes (about 55) and a lot of non-coding DNA – simple
repetitive DNA that doesn't seem to do anything.
But the Y chromosome packs a punch because it contains an all-important gene
that kick-starts male development in the embryo.
X 包含约 900 个基因，可以完成与性别无关的各种工作。但 Y 包含很少的基因（约 55
个）和大量非编码 DNA—简单的重复 DNA，似乎没有任何作用。
但 Y 染色体却具有强大的威力，因为它含有一个非常重要的基因，可以启动胚胎中的男
性发育。
At about 12 weeks after conception, this master gene switches on others that
regulate the development of a testis. The embryonic testis makes male
hormones (testosterone and its derivatives), which ensures the baby develops
as a boy.
This master sex gene was identified as SRY (sex region on the Y) in 1990. It
works by triggering a genetic pathway starting with a gene called SOX9 which
is key for male determination in all vertebrates, although it does not lie on
sex chromosomes.
受孕后约 12 周，这个主基因会启动其他调节睾丸发育的基因。胚胎睾丸会产生男性荷尔
蒙（睪固酮及其衍生物），确保婴儿发育为男孩。
1990年，这个主性基因被鉴定为SRY（Y上的性别区域）。它的工作原理是触发一条由
SOX9 基因开始的遗传途径，该基因是所有脊椎动物雄性决定的关键，尽管它并不位于性
染色体上。
The disappearing Y
Most mammals have an X and Y chromosome similar to ours; an X with lots of
genes, and a Y with SRY plus a few others. This system comes with problems
because of the unequal dosage of X genes in males and females.
How did such a weird system evolve? The surprising finding is that
Australia's platypus has completely different sex chromosomes, more like
those of birds.
消失的Y
大多数哺乳动物都有与我们相似的 X 和 Y 染色体；一个包含大量基因的 X，一个包含
SRY 和其他一些基因的 Y。由于男性和女性的 X 基因剂量不相等，该系统存在问题。
这么奇怪的系统是怎么进化出来的呢？令人惊讶的发现是，澳洲的鸭嘴兽有着完全不同的
性染色体，更像鸟类的性染色体。
In platypus, the XY pair is just an ordinary chromosome, with two equal
members. This suggests the mammal X and Y were an ordinary pair of
chromosomes not that long ago.
In turn, this must mean the Y chromosome has lost 900–55 active genes over
the 166 million years that humans and platypus have been evolving separately.
That's a loss of about five genes per million years. At this rate, the last
55 genes will be gone in 11 million years.
在鸭嘴兽中，XY 对只是一条普通的染色体，有两个相等的组成。这显示不久前哺乳动物
的 X 和 Y 是一对普通的染色体。
反过来，这必然意味着在人类和鸭嘴兽单独进化的 1.66 亿年里，Y 染色体失去了
900-55 个活跃基因。每百万年大约损失五个基因。照这个速度，最后55个基因将在1100
万年内消失。
Our claim of the imminent demise of the human Y created a furore, and to this
day there are claims and counterclaims about the expected lifetime of our Y
chromosome – estimates between infinity and a few thousand years.
Rodents with no Y chromosome
The good news is we know of two rodent lineages that have already lost their
Y chromosome – and are still surviving.
我们关于人类 Y 染色体即将灭亡的说法引起了轩然大波，直到今天，对于我们 Y 染色体
的预期寿命（估计在无穷到几千年之间）存有支持和反对意见。
没有Y染色体的囓齿类动物
好消息是我们知道有两个囓齿动物谱系已经失去了 Y 染色体，但仍然存活下来。
The mole voles of eastern Europe and the spiny rats of Japan each boast some
species in which the Y chromosome, and SRY, have completely disappeared. The
X chromosome remains, in a single or double dose in both sexes.
Although it's not yet clear how the mole voles determine sex without the SRY
gene, a team led by Hokkaido University biologist Asato Kuroiwa has had more
luck with the spiny rat – a group of three species on different Japanese
islands, all endangered.
东欧的鼹鼠和日本的刺鼠都拥有一些 Y 染色体和 SRY 完全消失的物种。无论是单剂量还
是双剂量，X 染色体都会保留。
尽管尚不清楚在没有SRY基因的情况下鼹鼠如何决定性别，但由北海道大学生物学家
Asato Kuroiwa领导的研究小组在刺鼠身上取得了更多的运气—刺鼠是分布在日本不同
岛屿上的三个物种，全部濒临灭绝。
Kuroiwa's team discovered most of the genes on the Y of spiny rats had been
relocated to other chromosomes. But she found no sign of SRY, nor the gene
that substitutes for it.
In 2022 they published a successful identification in PNAS. The team found
sequences that were in the genomes of males but not females, then refined
these and tested for the sequence on every individual rat.
黑岩的研究团队发现，多刺大鼠 Y 染色体上的大部分基因已被重新定位到其他染色体。
但她没有发现 SRY 的迹象，也没有发现替代它的基因。
2022年，他们在《PNAS》上发表了成功的鉴定结果。研究小组发现了雄性而非雌性基因组
中的序列，然后对这些序列进行了改进，并在每只老鼠身上测试了该序列。
What they discovered was a tiny difference near the key sex gene SOX9, on
chromosome 3 of the spiny rat. A small duplication (only 17,000 base pairs
out of more than 3 billion) was present in all males and no females.
They suggest this small bit of duplicated DNA contains the switch that
normally turns on SOX9 in response to SRY. When they introduced this
duplication into mice, they found that it boosts SOX9 activity, so the change
could allow SOX9 to work without SRY.
他们发现，多刺大鼠第 3 号染色体上的关键性基因 SOX9 附近有微小差异。所有男性中
都存在少量重复（超过 30 亿个碱基对中只有 17,000 个碱基对），而女性中没有。
他们认为这一小段复制DNA包含通常会响应SRY而打开SOX9的开关。当他们将这种重复引入
小鼠时，他们发现它增强了 SOX9 的活性，因此这种变化可以让 SOX9 在没有 SRY 的情
况下发挥作用。
What this means for the future of men
The imminent – evolutionarily speaking – disappearance of the human Y
chromosome has elicited speculation about our future.
Some lizards and snakes are female-only species and can make eggs out of
their own genes via what's known as parthenogenesis. But this can't happen in
humans or other mammals because we have at least 30 crucial "imprinted" genes
that work only if they come from the father via sperm.
这对男性的未来意味着什么
从演化的角度来说，人类 Y 染色体即将消失引发了人们对我们未来的猜测。
有些蜥蜴和蛇是雌性物种，可以透过所谓的单性生殖来利用自己的基因产卵。但这不可能
发生在人类或其他哺乳动物身上，因为我们至少有 30 个关键的“印记”基因，只有透过
精子来自父亲，它们才会起作用。
To reproduce, we need sperm and we need men, meaning that the end of the Y
chromosome could herald the extinction of the human race.
The new finding supports an alternative possibility – that humans can evolve
a new sex determining gene. Phew!
为了繁衍，我们需要精子，我们需要男人，这意味着Y染色体的末端可能预示着人类的灭
绝。
这项新发现支持了另一种可能性—人类可以进化出一种新的性别决定基因。唷！
However, evolution of a new sex determining gene comes with risks. What if
more than one new system evolves in different parts of the world?
A "war" of the sex genes could lead to the separation of new species, which
is exactly what has happened with mole voles and spiny rats.
然而，新的性别决定基因的演化也伴随着风险。如果世界不同地区出现多个新系统怎么办
？
性基因的“战争”可能导致新物种的分离，这正是鼹鼠和刺鼠所发生的情况。
So, if someone visited Earth in 11 million years, they might find no humans
– or several different human species, kept apart by their different sex
determination systems.The Conversation
Jenny Graves, Distinguished Professor of Genetics and Vice Chancellor's
Fellow, La Trobe University
因此，如果有人在 1100 万年后访问地球，他们可能会发现没有人类，或者发现几个不同
的人类物种，由于不同的性别决定系统而被隔开。对话
Jenny Graves ，拉筹伯大学遗传学杰出教授兼副校长研究员
5.完整新闻连结 (或短网址)不可用YAHOO、LINE、MSN等转载媒体:
https://reurl.cc/XRLDlR
6.备注:
结束了，以后没有男娘跟正太了。男生要好好保护自己。
https://youtu.be/VNl4J9b_xhE
只有百合的世界也不错吧？
https://youtu.be/9gXh8VOfQT4
鸭嘴兽真的是很邪门的生物...