Animals have been walking, crawling, flying, and otherwise moving around Earth for a very long time. Many millions of years ago, however, there were no animals as we know them. In fact, there were only single-celled organisms that could move around through the waters of the oceans.

Needless to say, these single-celled organisms were quite simple compared to what we see today, but they were still able to perform some incredible things.

Over time, those single-celled organisms were able to evolve into multicellular life, and eventually into all the living things we see around us. Scientists believe that single-celled organisms known as choanoflagellates are distant ancestors of modern animals. In their genomes, they had versions of the Sox and POU genes, which today are known to help create stem cells in mammals.

To attempt to prove this, researchers took these genes and inserted them into the cells of a mouse. The results were incredible and were published in the journal Nature Communications.

Dr. Alex de Mendoza put out a statement on the study where this was done, saying:

“By successfully creating a mouse using molecular tools derived from our single-celled relatives, we’re witnessing an extraordinary continuity of function across nearly a billion years of evolution. The study implies that key genes involved in stem cell formation might have originated far earlier than the stem cells themselves, perhaps helping pave the way for the multicellular life we see today.”

The team took choanoflagellate Sox genes and used them to replace the existing Sox2 genes in the mouse. This triggered the cells to turn into induced pluripotent stem cells (iPSCs), which can then develop into any type of cell in the body.

Once these iPSCs were injected into the developing embryo of the mouse, they were able to study the results. Interestingly, the results were quite visible once the mouse matured. It had black eyes and small black patches of fur, neither of which would have been possible if the mouse had been bred and developed normally.

Dr. de Mendoza explained how this happened:

“Choanoflagellates don’t have stem cells, they’re single-celled organisms, but they have these genes, likely to control basic cellular processes that multicellular animals probably later repurposed for building complex bodies.”

It is incredible what they are able to do, and this will help scientists to learn more about how single-celled organisms developed in the past and eventually evolved into modern animals.

I wonder what other differences will be found in this mouse.

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