Scientists have created an embryo of a six-legged mouse

Anastasiia Lozovska et al/Nat. Comms

Scientists have created a six-legged mouse embryo to understand how changes in the three-dimensional structure of DNA – the double helix – can affect the development of embryos.

According to the results of the study, which published in the journal Nature Communications, extra limbs grow where the rodent’s genitalia should be, writes Nature.

Researchers have known for a long time that in most four-legged animals, the external genitalia and hind limbs develop from the same primary structures.

Therefore, biologist Moises Mallo from the Gulbenkian Scientific Institute in Eiras (Portugal) and his colleagues studied one of the receptor proteins – Tgfbr1. It is involved in many aspects of embryo development.

During the development of the embryo, they first decreased the activity of microorganisms and protein substances that have the Tgfbr1 gene to see how it would affect spinal cord development.

They then discovered that one of the embryos had genitalia that looked like two extra hind limbs. And, as scientists say, this discovery has directed research in a new direction.

When scientists studied the embryo of a six-legged mouse in more detail, they found that the Tgfbr1 gene, changing the way DNA is folded in the cells of the structure, equally contributes to the development of genitals and limbs.

The deactivation of the protein changed the activity of other genes, which led to the appearance of additional limbs and the absence of true external genitalia, the scientists note.

The researchers hope to determine whether Tgfbr1 and its “relatives” affect DNA structure in other systems, particularly immune function.

They are also studying whether the same mechanism underlies the development of the hemipenis – the external sex organ of lizards – which in snakes is formed from primary organs instead of legs.

We used to reportedthat scientists have grown “mini-organs” from cells from amniotic fluid.