Meet the new star in the lab

For more than 50 years, researchers have used animals like mice and fruit flies to study human biology and disease. They have been indispensable in research – but they are, in fact, only distantly related to us.

This means that much laboratory research cannot be directly translated to humans – and that’s a major problem when, for example, we want to develop new treatments.

Now, two new studies recently published in the journal Nature point to a surprising candidate to help researchers move forward: the mouse lemur – a small, nocturnal primate from Madagascar.

It is more closely related to humans, yet still small enough to be practical for lab work. And millions of them exist in the wild.

A biological treasure trove

Together with colleagues from 15 research institutions worldwide, scientists from the Department of Biomedicine at Aarhus University have investigated whether the mouse lemur could serve as a suitable model for studying human biology and disease.

In one of the studies, the researchers created a detailed cell atlas of the mouse lemur, mapping which genes are active or inactive in over 226,000 cells from 27 different organs of the small primate. In the second study, they used the atlas to examine whether the mouse lemur’s cells more closely resemble those of humans or mice.

This is only the third time such an atlas has been created for a primate – previously it has been done for humans and macaques.

“A cell atlas provides a comprehensive overview of the location, function, and gene expression patterns of cells. In cases where the mouse lemur more accurately reflects human biology than mice, it could provide a significant boost to research,” says Associate Professor Antoine de Morree, who leads the project at Aarhus University.

The mouse lemur has over 400 genes that are shared with humans but not found in mice. Many of these genes are linked to disease. The mouse lemur can therefore help scientists study diseases that previously couldn’t be explored using animal models. Several of its cell types also more closely resemble human cells than those of the mouse.

“This isn’t just important for scientists. It means we may, in the future, be able to develop treatments based on animal models that resemble ourselves more closely – and are therefore more reliable. This can save time, money, and ultimately lives,” says Antoine de Morree.

A mouse lemur with cancer – and a new method

It came as a surprise when researchers discovered that one of the mouse lemurs had metastatic cancer in the uterus – a serious disease not found in mice.

“In many ways, it resembles the most aggressive form of uterine cancer in humans. By combining the cell atlas with tissue analyses, we were able to trace both the origin of the cancer and its spread throughout the body,” explains Antoine de Morree.

“Our results demonstrate how a cell atlas, combined with histology, can be used to identify the primary site of cancers of unknown origin, which account for about two percent of all human cancers. It allows us to uncover how a disease develops and affects the body at both the cellular and molecular levels,” he says.

“We call it a ‘molecular cell autopsy,’ and it’s a completely new method that could become a crucial tool in understanding how diseases develop – and how they can be treated.”

Supporting local researchers in Madagascar

At the same time, the mouse lemur’s new role in research could strengthen the scientific environment in Madagascar, where the species originates. Local researchers have been involved in the study from the outset, which could enhance both education and scientific capacity in one of the world’s poorest countries.

“The mouse lemur isn’t just exciting in itself – it also shows how we can find new, sustainable ways to conduct research,” says Antoine de Morree.

Contact:

Associate Professor Antoine de Morree
Aarhus University, Department of Biomedicine
Phone: +45 60 79 07 22
Email: demorree@biomed.au.dk