Scientists accidentally created an unusual mouse embryo with six legs but no genitals. This never-before-seen creature demonstrated how DNA alterations can have serious consequences for development.
A team of scientists from Portugal’s Gulbenkian Science Institute was attempting to understand how a certain protein functions in the middle stages of the embryo’s growth.
Embryos begin as a bundle of identical cells. When cells mature, they specialize and begin to build various bodily parts. In general, development begins in the head and progresses back to the tail. Human embryos also have tails in the early stages, but they disappear after about eight weeks.
Scientists understand that in most four-limbed mammals, the hind limbs and external genitalia (the penis or clitoris) develop from the same early structures.
The researchers inactivated Tgfbr1 in mouse embryos around midway through development
The research team, led by developmental biologist Moises Mallo, focused on a specific receptor protein known as Tgfbr1.
The protein, technically known as transforming growth factor beta receptor I, regulates gene expression. It aids in determining which cells should be activated and in what location, as well as what each cell should become- a blood cell, muscle tissue, or nerve cell.
In this landmark study, the researchers inactivated Tgfbr1 in mouse embryos around midway through development to see how the spinal cord’s development was affected.
The researchers discovered an embryo that had developed additional limbs but no genitals. Additionally, other organs were developing outside of its body.
It appeared that with the absence of this protein, other genes were activated, and the cells developed into additional legs rather than genitals.
The scientists are now hopeful that additional research will help them discover whether Tgfbr1 and its relatives can influence DNA in other systems, such as metastatic cancer.
In a paper published in the journal Nature Communications, the researchers stated, “Identification (the) mechanisms and determining whether they also operate in other physiological and pathological processes under the control of members of the (Tgfbr1) family might have far-reaching implications for our understanding of morphogenetic processes and disease.”
The DNA of tumors is already targeted by existing cancer treatments, providing better knowledge of how they work and helping scientists create new and better options.