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How do you make sperm?

Right now, it’s only being made inside human bodies with the right combination of body parts and hormones. But with the results of Dr. Heather Steele’s research, making sperm could also be happening in labs around the world.

“Right now, in the lab, we can’t make sperm — we can’t replicate what happens in the body,” says Steele, PhD, Eyes High postdoctoral scholar in the Faculty of Veterinary Medicine. If someone can’t produce sperm naturally, having biological children of their own isn’t an option — yet.

“Infertility is a huge challenge,” says Steele. “One in six couples will suffer with infertility and that number is only growing. We need methods to preserve fertility.”

To do so, researchers need to understand how fertility happens in the first place. In Steele’s case, this is looking at how certain cells in the testes ‘tell’ other cells to ‘flip the switch’ and begin the process of turning into sperm.

Male childhood cancer patients' infertility risk

Steele arrived at ��ݮ����Ƶ���� in January 2022 as an Eyes High Postdoctoral Scholar, joining Dr. Ina Dobrinski’s lab for a two-year term. Steele is one of 21 postdocs to join ��ݮ����Ƶ���� through the fall 2021 round of the program.

• See a full list of new Eyes High postdocs at the end of this article.

Steele is focusing on preserving the fertility of male childhood cancer patients. Chemotherapy and radiation put them at a nearly 30 per cent risk of infertility. They also receive cancer treatment before puberty, when they are unable to produce sperm, so unlike adult men they can’t store sperm for future use prior to beginning cancer treatment.

That’s where Steele’s research comes in.

Currently, these patients are offered the chance to preserve reproductive tissue that may be key to restoring their fertility in adulthood — researchers just have to figure out how. They need to determine how to start the production of sperm in the lab from the preserved tissue in order to restore a patient’s fertility.

How do cells communicate?

One obstacle is the lack of understanding of how cells communicate as they mature in the testes to become sperm.

“My project is looking at communication between Sertoli cells, the cells in the testes that support sperm development, and germ cells, the ones that produce sperm,” she says. “We think that the Sertoli cells send signals to the germ cells to say, ‘Time to start making sperm’, so we’re trying to see what those signals are. Then we can apply those signals to testis tissue in the lab to attempt to induce sperm production.”

Steele will separate out the two types of cells from animal testis tissue, and then grow the Sertoli and germ cells separately in the lab. As they grow, the Sertoli cells secrete exosomes that contain "signals" for other cells. They may include the "time to make sperm" signal that germ cells need to start the sperm production process. Steele will isolate and analyze the exosome signals and determine how to apply them to testis tissue.

First step in longer process to restore fertility

Steele will conduct her research using one-of-a-kind organoid model technology unique to the Dobrinski Lab. The isolated signals will be applied to the organoid system, a 3D structure containing Sertoli and germ cells. Steele will examine how the germs cells respond to the signals, in the hope that they will begin the process of becoming sperm.

This research is the first step in a longer process. By better understanding Sertoli-germ cell "communication," the Dobrinski lab could then manipulate the germ cells to produce sperm in the lab. Once translated to humans, this would allow for fertility restoration for childhood cancer survivors.

Steele is optimistic about the work, and the potential it holds for those struggling with infertility.

“This work is so important because it will give us a way to help restore fertility and offer patients a chance to have their own family.”

Eyes High Postdoctoral Match Funding program spring 2022 intake now open

The Eyes High Postdoctoral Match Funding program is now open for the spring 2022 intake, and closes May 6, 2022. This program awards partial salary support for postdocs who will be highly competitive for external awards and will help advance ��ݮ����Ƶ����’s strategic research and innovation plan. Funding is awarded on a competitive basis.

“T��� Eyes High postdoc program attracts high-calibre applicants from around the world,” says Dr. Penny Pexman, postdoctoral program director. “Postdocs have tremendous capacity for discovery and innovation, and bring fresh ideas to our campus. We’re excited to be offering a fourth round of this program, which is a great opportunity for faculty and postdocs alike.”

For more information on the Eyes High Postdoctoral Match Funding program, visit the .

• Dr. Asmaa Ahmed, PhD, Schulich School of Engineering (Dr. Mamdouh El-Badry, PhD)
• Dr. Flavia Antunes, PhD, Cumming School of Medicine (Dr. Gerald Zamponi, PhD)
• Dr. Mingyuan Cao, PhD, Schulich School of Engineering, (Dr. Hua Song, PhD)
• Dr. Birk Härtel, PhD, Faculty of Science (Dr. Eva Enkelmann, PhD)
• Dr. Travis Hnidan, PhD, Schulich School of Engineering (Dr. Kerry Black, PhD)
• Dr. Kenneth Lai, PhD, Cumming School of Medicine (Dr. Mohammed Almekhlafi, PhD)
• Dr. Jangwoo Lee, PhD, Faculty of Science (Dr. Casey Hubert, PhD)
• Dr. Shimeng Liu, PhD, Werklund School of Education (Dr. Kim Koh, PhD)
• Dr. Shuhiba Mohammad, PhD, Cumming School of Medicine (Dr. Myriam Hemberger, PhD)
• Dr. Emad Naseri, PhD, Schulich School of Engineering (Dr. Keekyoung Kim, PhD)
• Dr. Camille Petitfils, PhD, Cumming School of Medicine (Dr. Kathy McCoy, PhD)
• Dr. Vinay Saini, PhD, Schulich School of Engineering (Dr. Philip Egberts, PhD & Dr. Milana Trifkovic, PhD)
• Dr. Mahmoud Sakr, PhD, Schulich School of Engineering (Dr. Jinguang Hu, PhD)
• Dr. Rachel Sharkey, PhD, Cumming School of Medicine (Dr. Richard Frayne, PhD & Dr. Shalina Ousman, PhD)
• Dr. Li Shu, PhD, Cumming School of Medicine (Dr. Maja Tarailo-Graovac, PhD)
• Dr. Mohammed Abdul Qadeer Siddiqui, PhD, Schulich School of Engineering, (Dr. Hassan Hassanzadeh, PhD)
• Dr. Vishal Singh, PhD, Cumming School of Medicine (Dr. Pere Santamaria, MD, PhD)
• Dr. Heather Steele, PhD, Faculty of Veterinary Medicine (Dr. Ina Dobrinski, PhD)
• Dr. Irina Terentieva, PhD, Faculty of Arts (Dr. Greg McDermid, PhD)
• Dr. Rosslynn Zulla, PhD, Faculty of Social Work (Dr. David Nicholas, PhD)