Paul Turek

And 98% of sperm are typically normal. In a guy with infertility, it might be 95%. Here's an example. If you have a patient with Klinefelter syndrome, a male with an extra X chromosome in every cell in their body, or a transgenic model with that feature.

And 98% of sperm are typically normal. In a guy with infertility, it might be 95%. Here's an example. If you have a patient with Klinefelter syndrome, a male with an extra X chromosome in every cell in their body, or a transgenic model with that feature.

Okay.

Okay.

That's the MCAT question. Yep, yep. All right. So in these men, if you look at their sperm aneuploidy, right? So every cell in their body and in the mice, in the transgenic mice, all have an extra X chromosome. Only about 10% will have it in the sperm.

That's the MCAT question. Yep, yep. All right. So in these men, if you look at their sperm aneuploidy, right? So every cell in their body and in the mice, in the transgenic mice, all have an extra X chromosome. Only about 10% will have it in the sperm.

That's math, Peter. That's math. Biology is not math, remember? And I had two Kleinfeldt patients yesterday that I operated on, and they're not doing pre-implantation genetic diagnosis of the embryos that they're going to create from their sperm because the chance is not that high. So it goes from, in mice, 0.1% chance of normal men having XXY sperm or an aneuploid sperm, an abnormal sperm, to 1%.

That's math, Peter. That's math. Biology is not math, remember? And I had two Kleinfeldt patients yesterday that I operated on, and they're not doing pre-implantation genetic diagnosis of the embryos that they're going to create from their sperm because the chance is not that high. So it goes from, in mice, 0.1% chance of normal men having XXY sperm or an aneuploid sperm, an abnormal sperm, to 1%.

In humans, it goes from 1% or so to 10%. But 90%, that's remarkable. That's amazing. It's remarkable how efficient this is.

In humans, it goes from 1% or so to 10%. But 90%, that's remarkable. That's amazing. It's remarkable how efficient this is.

Yeah.

Yeah.

We don't know is the answer. Right. And it's interesting that ovaries are inside. So men get in hot baths and they're cooked.

We don't know is the answer. Right. And it's interesting that ovaries are inside. So men get in hot baths and they're cooked.

Spermiogenesis is when You go from the round cell stage and you get half the number of chromosomes and then you have to make a tail and then a whole motor assembly. And that is the most profound transformation of a cell in the body. It takes about three weeks to go from that stage. And we're learning now it's a lot of it's vitamin A driven. Three weeks? Of the six or seven to make a sperm.

Spermiogenesis is when You go from the round cell stage and you get half the number of chromosomes and then you have to make a tail and then a whole motor assembly. And that is the most profound transformation of a cell in the body. It takes about three weeks to go from that stage. And we're learning now it's a lot of it's vitamin A driven. Three weeks? Of the six or seven to make a sperm.

Then it's complete and non-modal and it's packaged.

Then it's complete and non-modal and it's packaged.

And then the tail makes it... 35 micron tail, yeah. So really magnificent engineering feat. It's got microtubules in the middle and there's these links to the tail. It's like a kite and the engine runs it and the tail wags. Remarkable. 300 genes control movement of sperm alone. There's mitochondrial DNA in there, all that stuff.

And then the tail makes it... 35 micron tail, yeah. So really magnificent engineering feat. It's got microtubules in the middle and there's these links to the tail. It's like a kite and the engine runs it and the tail wags. Remarkable. 300 genes control movement of sperm alone. There's mitochondrial DNA in there, all that stuff.