A team of researchers has successfully raised a mouse to adulthood that was produced from a single unfertilized egg.

This method of asexual reproduction called parthenogenesis occurs naturally in several animal species, including some sharks, lizards, and birds. This results in offspring containing half or all of their mother’s genetic material, but requiring no genetic input from a male sex cell. It was previously thought to be impossible in mammals, for new scientistis Alex Wilkins.

“The success of parthenogenesis in mammals opens many opportunities in agriculture, research and medicine,” write the authors in their study published in the journal Proceedings of the National Academy of Sciences. “Further identification and editing of additional KPIs [imprinting control regions] could improve the efficiency of parthenogenetic development.

Previous research aimed at forcing mammals to reproduce through parthenogenesis has failed due to genomic fingerprintingby a declaration. In normal sexual reproduction, the offspring receives two copies of a gene, one from each parent. But genomic imprinting means that certain genes are chemically marked to indicate which parent they came from, resulting in the expression of only one copy of the gene.

The research team used the CRISPR gene editing tool to target seven of these imprinted genetic regions and change the tags, making the mother’s genetic code look like it came from a male, for new scientist. They then injected an enzyme into the egg to activate certain genes and others to mimic a male-fertilized egg, according to the statement.

“This is going to turn out to be an important piece of the puzzle regarding the mechanism of very early embryonic development and how the two parental genomes are regulated,” says biochemist Tony Perry of the University of Bath in the UK, who was not involved in the study, says new scientist. “And second, it’s an important technical demonstration of the kind of power these [CRISPR tools].”

The researchers transferred 192 parthenogenetic embryos into 14 female mice. Three living baby mice were born, but only one survived to adulthood, according to the study. The mouse appeared to have a normal body weight at birth, but as it grew into adulthood, it showed about a 20 percent reduction in body weight compared to control mice in the study. Despite this, the mouse was able to reproduce normally with a male.

“I think there are people who will look at this and say, ‘Oh, is this going to replace reproduction? Get rid of men? No, it’s not,” said Marisa Bartolomei, a molecular biologist at the University of Pennsylvania who was not involved in the study. The daily beastThis is Miriam Fauzia. It could, however, help research into diseases caused by genomic imprinting, such as Prader-Willi syndrome or Beckwith-Wiedemann syndrome, according to the publication.

Future research will be needed to improve the process and the success rate of viable offspring, the authors write.