Scientists change the rules of reproduction in mammals

In a breakthrough in the field of epigenetics, scientists at the Chinese Academy of Sciences have achieved an unusual success by changing the rules of reproduction.

They have managed to overcome the male-woman's joint barrier for sexual reproduction to mammals for the first time, using 210 embryos to create 29 live and healthy mice with two mothers, but without a father.

We were interested in why mammals cannot be subjected only to sexual reproduction”, Says research co-author Qi Zhou.

Parthenogenes, or reproduction without sperm, is common among insects, fish, and lizards, but not in mammals.

The team focused on about 100 genes that are activated when they come from both parents, for an accurate development.

However, using only the genetic material obtained from two female mice, the team began to erase several important sequences in the DNA of embryoal stem cells, using the Crispr-Cass9 genetic cutout.

Traditionally, problems arise when trying to reproduce clones using DNA from single-gender parents.

Japanese researchers were able to overcome this obstacle in 2004, but the procedure was considered inefficient and costly. However, epigenetics has advanced greatly in the next 14 years.

Chinese researchers have strategically erased separate regions in the women's stem cell chromosomes, thus making them closer to the embryo's primary cells, “eggs forwarders and sperm players”, according to Baiang Hu, also senior coauthor in the study.

However, the current technique is not perfect: only 29 live mice have been produced by 210 embryos. Besides, this success cannot be repeated on male mouse babies. 12 rats born in this form have failed to survive more than 48 hours.