Every once in a while, when we do that test and we sequence that DNA, there's an extra chromosome 21,13, or 18, or a change in the sex chromosome material.

偶尔进行该检测时，我们会发现额 21 、13 或 18 染色体，或者性染色体异常变化。

Typically a gamete with 23 chromosomes, including one sex chromosome either X or Y, develops when parent germ cells undergo the process of meiosis.

正常配子包含23条染色体，其中有一条X或Y性染色体，由亲代生殖细胞减数分裂产生。

One of these pairs, the sex chromosomes, determines person's biological sex and it can be composed of either two X chromosomes for females or an X and a Y chromosome for males.

23对染色体中，有一对是性染色体，它决定了人生物性别；对于女性，它由两条X染色体组成，男性则由一条X染色体和一条Y染色体组成。

In Klinefelter syndrome, the sex chromosome pairs which is either XX or XY don't separate in meiosis I in the male or female germ cell and this resulted in two gametes with a pair of X chromosomes and two gametes without X chromosomes.

Klinefelter综合征中，配对XX或XY性染色体对父亲或母亲第一次减数分裂中没有分离，从而产生了两个有两条X染色体配子以及两个没有X染色体配子。

This can happen as a result of nondisjunction of sex chromosomes during meiosis, and it happens more frequently in sperm cells - but egg cells can also be affected.

这可能是由于细胞减数分裂期间性染色体未分离而造成，而且这一情况精子细胞中发生得更繁，不过卵细胞中也可能出现。

And the reason why is that you get a duplication of the sex chromosomes.

其原因是性染色体会发生复制。

So around 1960 -- this is going to be our first stop on the complicated world of the sex chromosomes -- so around 1960, we had discovered that you could be XYY. They discovered an XYY man.

所以 1960 年左右——这将是我们探索复杂性染色体世界第一站——所以 1960 年左右，我们发现你可以是 XYY。他们发现了一个 XYY 人。

Like, it can mean having different combinations of sex chromosomes – as in Klinefelter Syndrome, which creates chromosomes XX and Y, or in Triple-X Syndrome, which results in XXX.

比如，这可能意味着拥有不同性染色体组合——就像克兰费尔特综合征，它导致XX和Y染色体形成， 或者三X综合征， 结果是XXX染色体。

Variants in many other genes may also prevent production of either eggs or sperm. Some people even have different combinations of sex chromosomes in different cells of their bodies.

许多其他基因变异也可能阻止卵子或精子产生。有些人甚至身体不同细胞中拥有不同性染色体组合。

None of those markers was on the x or y sex chromosomes and their total combined effect accounted for less than 1% of the variance.

这些标记都不位于X或Y性染色体上，它们总联合效应不到变异1%。

As they go from a cell with 46 chromosomes to a sex cell with only 23, the chromosomes within each pair swap some sections.

当它们从一个有 46 条染色体细胞变成一个只有 23 条染色体性细胞时，每对染色体中染色体会交换一些部分。

While there may be an advantage to having two big sex chromosomes, there's also evidence there's  a disadvantage to having a small chromosome.

虽然拥有两条较大性染色体可能有优势，但也有证据表明拥有一条较小性染色体有劣势。

So the study showed us for the first time the importance of sex hormones and sex chromosomes working together to influence...

所以这项研究首次向我们展示了性激素和性染色体共同作用以影响… … 重要性。

The five A longstanding hypothesis holds the sex chromosomes to blame Male mammals are in the jargon heterogometic.

一个长期假设认为，性染色体是罪魁祸首。雄性哺乳动物行话中被称为异配性别。

Those developmental processes are partially directed by X and Y chromosomes. Though often called sex chromosomes, that name is somewhat misleading. In fact, the X and Y chromosomes have a wide range of jobs.

这些发育过程部分由X和Y染色体引导。尽管通常被称为性染色体，但这一名称有些误导。实际上，X和Y染色体承担着广泛功能。

There are two possible explanations for why  this trend exists: one is that having more big sex chromosomes is better, and the other  is that having a small sex chromosome is worse.

这种趋势存原因可能有两种：一是拥有更多大性染色体更好，另一种是拥有较小性染色体更糟糕。

And so what we think happened in this rat is they actually shed that extra xy chromosome or those sex chromosomes and they're able to reproduce as a tetraploid animal.

因此，我们认为这种老鼠身上发生情况是，它们实际上失去了那个额XY染色体或那些性染色体，并且能够以四倍体动物身份进行繁殖。

And you can see they ended up getting " sex chromosome" -- it's like a pretty juicy title, it popularized genetics, you know?

你可以看到他们最终得到了“性染色体”——这就像一个非常有趣标题，它普及了遗传学，你知道吗？

In other words if genes are ever on the same chromosome or on a sex chromosome or caused by multi genes, it's really complex, and so I'll talk about those in the next podcast on advanced genetics.

换句话说，如果基因位于同一染色体上， 或位于性染色体上， 或是由多个基因引起，情况就会变得非常复杂。因此，我将下一期关于高级遗传学播客中讨论这些问题。

And eventually, someone was like, " Well, if that one thing's called X, should we call this other thing Y? " And like that, (Snaps fingers) the sex chromosomes had been discovered.

最后，有人说，“好吧，如果那个东西叫 X，我们应该把另一个东西叫 Y 吗？ ” 就这样，（打响指）性染色体被发现了。