Carole Hooven, Ph.D.

It gets bigger.

But if you take what looks like even adult female genitalia,

basically you modify the clitoris and the labia to get what looks like typical male genitalia.

So that has to do a lot of growing and changing.

And it's like that in the fetus.

So if we're going down the male route, you get the expression of SRY.

And what that does is it causes certain cells in this

undifferentiated gonad to develop into first Leydig cells and then later Sertoli cells.

So that's happening.

And then later, ovarian differentiation takes place.

So two things happen.

The Leydig cells start producing testosterone first.

And I'm going to go back and just talk about the Wolfian ducts and the Malarian ducts.

Okay.

So this is D-U-C-T-S, not duck like quack quack.

So these are duct systems.

And so here's another cool thing.

So we should start out with this two primordial or primitive gonads that can become either a

So obviously the males have to descend into what becomes the scrotum and the females just stay there.

And that seems very sensible.