We know much about how embryos develop, but one key stage -- implantation -- has remained a mystery. Now, scientists from Cambridge have discovered a way to study and film this 'black box' of development. Their results -- which will lead to the rewriting of biology text books worldwide -- are published in the journal Cell.
Embryo development in mammals occurs in two phases. During the first phase, pre-implantation, the embryo is a small, free-floating ball of cells called a blastocyst. In the second, post-implantation, phase the blastocyst embeds itself in the mother's uterus.
While blastocysts can be grown and studied outside the body, the same has not been true from implantation. And because embryos are so closely connected to their mothers, implantation has also been difficult to study in the womb.
According to study author Professor Magdalena Zernicka-Goetz of the University of Cambridge: "We know a lot about pre-implantation, but what happens after implantation -- and particularly the moment of implantation -- is an enigma."
Scientists are interested in studying implantation because the embryo undergoes huge changes in such a short space of time.
"During these two days, it goes from a relatively simple ball to a much larger, more complex cup-like structure, but exactly how that happens was a mystery -- a black box of development. That is why we needed to develop a method that would allow us to culture and study embryos during implantation," she explained.
Working with mouse cells, Professor Zernicka-Goetz and her colleague Dr Ivan Bedzhov succeeded in creating the right conditions outside the womb to study the implantation process.To read more, click here.