Lab-made sperms to help understand infertility

Lab-made sperms? Sounds like something out of a science fiction movie but it is not as impossible as you think. In fact, we are almost there.

In 2009, two groups of scientists claimed that they could create sperms in the lab. Other reports have misleadingly used the term “artificial” sperms but there was actually nothing artificial about those sperms. They were human sperms, alright.

Sperms and eggs are collectively called gametes, cells which have only one copy of chromosomes instead of the usual two, thus specially designed for reproduction, e.g. for DNA recombination. Gametes are derived from special cells called germ cells. The transformation of germ cells into eggs and sperm is a long and complicated process which can only take place in the human reproductive organs. However, scientists report that they may finally be able to simulate the processes involved in the lab, including meiosis, a complicated type of cell division that enables the division of the chromosome number into half.

I hereby describe the two studies that supposedly produced lab-made sperms.

Study # 1:

In July 2009, scientists from the University of Newcastle reported that they were able to create human sperms in the lab for the first time. Using human embryos left over from IVF procedures, the scientists were able to grow stem cells. The stem cells were induced to become germ cells, the precursors of gametes.

The stem cells were brought to body temperature and put in a chemical mixture to encourage them to grow. They were “tagged” with a genetic marker which enabled the scientists to identify and separate so-called “germline” stem cells from which eggs and sperm are developed.

The male, XY stem cells underwent the crucial process of “meiosis” – halving the number of chromosomes. The process over creating and developing the sperm took four to six weeks

The resulting gametes were mature sperms which were healthy and motile. The results were published in the journal Stem Cells and Development. Unfortunately, the paper was later retracted amidst accusations of plagiarism.

Study # 2:

In October 2009, researcher at Stanford University claimed they’ve done it as well. They, too, managed to turn embryonic stem cells into germ lines, and then on to produce spermatids or immature sperms. The fact that the results were published in the journal Nature gave these claims more credibility than the previous one.

According to study author Dr. Renee Riejo Pera

“Germ cells in humans normally develop between day 12 after fertilization through the first trimester. That is a place we can’t look. We can’t see because obviously it is in utero.”  

But with their new technique, they can.

“[Now] We are really trying to look at the origins of normal and abnormal human development by going to the source.”

There are people who are horrified by these new developments. There are also those who are jubilant.

What  are the objections to these new developments?

The ethical issues. This is, first and foremost, interfering with nature and playing good, some people would say.

The cost. Some people would question the amount of money spent on such a venture. After all, there are more than enough naturally made sperms in sperm banks the world over.

How can we put these new discoveries to use?

Understanding the causes of infertility, especially in men. A large number of infertility problems is due to sperm insufficiency. Environmental factors have been linked to low sperm count and poor sperm motility, thus infertility. In simulating the process of sperm production, scientists may find out what are the causes behind infertility and how important is the role of the environment.

Treating genetic diseases. Some genetic defects are passed on from father to child. In understanding the mechanism behind the transmission of these defects from one generation to the other, we might be closer to finding the cure for them.

Understanding human development. By going back right to the very beginning when gametes are formed, we are seeing a clearer picture of how human life really starts.

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