The targets of the testosterone are the outermost cells in the tubules, called spermatogonia.

睾酮目标是小管中最细胞，称为精原细胞。

But when puberty starts, the testosterone causes them to divide differently — instead of splitting into two identical spermatagonia cells, they begin producing two distinct spermatogonia.

但是当青春期开始时，睾丸激素导致它们以不同方式裂——而不是裂成两个相同精原细胞，它们开始产生两个不同精原细胞。

And considering how many spermatogonia are continuously dividing into spermatocytes, it's easy to see how a mature male can crank out 1500 sperm a second.

有多少精原细胞不断裂成精母细胞，很容易看出一个成熟男性是如何每秒产生 1500 个精子。

And actually, they've been doing that all along — even before puberty. Throughout childhood, a spermatogonia cell uses mitosis to continuously divide into two identical daughter cells.

事实上，它们一直都在这样做——甚至在青春期之前。在整个童年时期，精原细胞通过有丝裂不断裂成两个相同子细胞。

One type of daughter cell — known as a type A cell — stays up near the basal lamina and just keeps dividing, so you never run out of spermatogonia.

有一种子细胞——也就是众所周知 A 型细胞——会待在基底附近并不断裂，所以精原细胞永远不会耗尽。