Scientists Attempt to Clone Mice From Poop
In a new study published in Scientific Reports, scientists from the University of Yamanashi in Japan decribed their attempts to clone mice from feces. As you can imagine, the process was a little messy.
Lead author Satoshi Kamimura and his colleagues aimed to use nuclear transfer to accomplish the feat. This is the same strategy previously utilized to clone Dolly the Sheep in 1996, as well as two monkeys earlier this year.
The researchers first attempted to collect cells from the surface of mice droppings. A process of harvesting, centrifuging, mixing in solution, and centrifuging again yielded what the authors termed "cell-like bodies." Kamimura and his team hoped that most of these were epidermal cells from the mice intestines, but because many of the harvested cells were damaged, they couldn't be sure. Inserting the cells' nuclei into mouse egg cells stripped of their nuclei led to the formation of a basic pronucleus in up to a quarter of cases. Development didn't go much farther, however.
"The reconstructed... embryos showed several abnormalities, such as shrunken nuclear membranes and abnormal distribution of tubulin, and none of them developed beyond one-cell stage embryos," the authors described.
Subsequent experiments revealed that these developmental failures were likely caused by toxic substances within the feces, such as bile acid and endotoxins from bacteria. DNA damage within donor cell nuclei, inflicted within the unforgiving intestinal environment, also hindered development.
When the researchers took extra care to decontaminate donor nuclei from intestinal cells, results improved, but only slightly. Seven out of 18 cloned embryos divided once, reaching a two-cell stage.
"However, none of them developed beyond this stage, even cultured up to 4 days," the researchers wrote.
The results of the study suggest that cloning animals from their feces won't happen anytime soon. Still, the authors are hopeful that once methods for decontaminating cells and repairing nuclei are improved, it could be a possibility.
"Feces cells might be useful for the conservation of endangered species when technical improvements are achieved," the researchers say.
Source: Kamimura et al. "Generation of two-cell cloned embryos from mouse faecal cell." Scientific Reports volume 8, Article number: 14922 (2018) https://www.nature.com/articles/s41598-018-33304-2