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Award-winning urologist - and pioneer in Men's Health - Dr. Paul Turek blogs weekly about issues such as infertility, vasectomy and vasectomy reversal, sexual and hormonal dysfunction and more. Keep up with the latest on this fascinating field of medicine.

Mice Sperm in a Dish

Artificial mouse sperm made in a dish
If they just would have included a photo of the finished product...

It’s not the mother load of discoveries in our field, but it’s pretty close. It tells us that the mother load is definitely out there…and within reach. Yup, the good news is that real. live, old-fashioned sperm were made in a dish… at least for mice.

The Holy Grail: Artificial Sperm

For the 55,000 reproductive age cancers survivors annually in the U.S. and a host of other men who are sterile due to injury, genetics, exposures and the like, this is good news. Despite the availability of utterly fantastic reproductive technologies like sperm mapping, in vitro fertilization and intracytoplasmic sperm injection, some men still do not have sperm to use them. The standard of care in reproductive medicine today is a sperm: a mature one, with a tail, and hopefully moving or at least alive.

And the sperm can come from anywhere. Often, men with no sperm in the ejaculate will have sperm within the reproductive organs such as the testicle or epididymis. These sperm work great to help them become fathers. But there are many other men do not have any sperm, anywhere, especially men with childhood cancers who were blasted with sterilizing treatments before they even reached puberty and made their first sperm. Clinically, I see these patients all the time and this is the crowd of men I am very motivated to help in my short time on this good earth.

The Finding: Functional Sperm for Mice

The recipe to produce functional sperm from stem cells precursors has eluded researchers for 50 years. There have been many false starts, including the last one in 2009 out of Newcastle that was published and then retracted from print by the editors one week later. But, a group from Yokohama City Japan nailed it and recently published functional mouse sperm from testis stem cell precursors.

From reading the paper, it is clear that it took several years of constant, diligent work to find the key ingredients to make it happen. In my opinion, the secret sauce was that our recent, vastly improved understanding of stem cell biology really enlightened the science. They took testicular tissue from newly born mice that contained only stem cells (no sperm, just sperm precursors) and put them in a jello-like environment. Getting them to grow was the trickiest part and finding the right food was also critical.

How is This Sperm Different?

What made this paper great was that the scientists made reproductively “competent” sperm. They took the artificially created sperm and used them with high technology approaches to create baby mice. Then, they let the baby mice grow up and mate. Remarkably, the offspring of these mated mice were normal. Can’t ask for much more from a sperm now can we? Many have tried, including some of my closest colleagues, but no one has gone this far before. Bravo!

So now, all we have to do is replicate this in humans, something that I have been pursuing for several years with colleagues. What is so uplifting for me about this paper is that it seems that making human sperm in a dish is really more evolutionary than revolutionary science. I better go buy some more of that midnight oil….

24 Responses to “Mice Sperm in a Dish”

  1. AJR

    doing great work Dr Paul! I guess if you’re helping the guys, then you’re also helping the gals.

  2. RP

    This is great news Dr. Turek, thanks for posting this info. Do you think they will have any human trials in the near future (I doubt it will be soon)?

    • Paul Turek, MD turek

      Richard, We are currently enrolling Y chromosome deleted, FNA map-negative men for a clinical trial at Stanford University that it somewhat similar to this. We are taking a routine skin biopsy and transforming these skin cells into adult induced pluripotency stem cells (iPS cells). We are planning then to “drive” these cells to sperm in a dish, but this second part will take a few years to perfect.

  3. The Recipe for Man Made Sperm | Staging Web Site

    […] stem cells appear to be great to use to create sperm. Just a few posts ago, I shared the exciting findings from a group in Japan who took stem cells from newborn mouse […]

  4. JR

    I spoke to a doctor in Israel who wants to try to use stem cells to create sperm for me and he thinks there is a good chance it will work, but he cannot ‘promise’ success. I do not want to be a guinea pig. When will human trials begin? Thanks.

  5. JR

    How come it will take a few years longer over here than is stated by doctors in Israel/Europe. Is that because of more stringent rules here? Are the doctors over there given more room to experiment than in the US with less repercussions?

  6. JR

    As i posted previously, I have an azfc deletion with azoospermia as a result. Do you need additional volunteers like me to come to San Francisco for a skin biopsy to speed up the research, or should I just wait for you to contact me at the right time? Thanks.

    • Paul Turek, MD Paul Turek, MD

      Keep the hope alive. No news yet. Consider freezing eggs in case things turn the corner in the next several years.

  7. ahmad

    Hi Dr Turek , JR

    I read your comment earlier about a israli doctor doing stem cell sperm treatment . Please could you share his name please.

    Apologies Dr Turek for using this forum to get this info but I am desperate to become a biological father.


    You mentioned a doctor in Israel whom will do the stem cell sperm treatment for you. Please can you let me know his name.

    Apologies Dr turek for using this forum to get these details but I am desperate to become a father.
    You mentioned a clinic In Israel that will crrate sperm from stem cells. How did you get on with this and please can you send me the details for the doctor .

    Many thanks, apologies Dr Turek for using this forum to contact other doctors but I have sertoli only cell syndrome and desperate to become a father . Thank you

    • Paul Turek, MD Paul Turek, MD

      Ahmad, I do not know personally of any doctor doing the type of stem cell research that we are doing.

  8. Stefan

    why all of this goes so slowwww? Please dr Turek bring hapiness in our lifes, we are desperate to have our children but this waiting is…… 🙁 🙁 🙁

    • Paul Turek, MD Paul Turek, MD

      Ahmad, yes this is good news. We have been making adult stem cells from skin at Stanford (with Dr. Renee Reijo Pera) for several years in preparation for turning them into germ/sperm cells. However, this Nature paper describes turning adult skin cells into true embryonic stem cells (not adult stem cells). This might be a critical difference as we attempt to make sperm from different types of stem cells down the line.


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