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.

青春期开始时，睾丸激素导致它们以同方式裂——而裂成两个相同精原细胞，它们开始产生两个同精原细胞。

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

睾酮目标小管中最外层细胞，称为精原细胞。

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.

考虑到有多少精原细胞裂成精母细胞，很容易看出一个成熟男性如何每秒产生 1500 个精子。

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——也就众所周知 A 型细胞——会待在基底层附近并裂，所以精原细胞永远会耗尽。

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裂成两个相同子细胞。