Scientists reveal mystery of reproductive cycle

Two scientists from Cambridge University developed a new way to study, and film, part of the reproductive cycle that has never before been observed.

Ivan Bedzhov and Magdalena Zernicka-Goetz discovered a new way to study how embryos develop after implantation in the uterine lining.

The scientists developed a system that mimics the conditions inside the uterus — a gel medium that shares the same chemical and biological properties as uterine tissue. This gel is transparent to optical light, allowing the blastocysts to be photographed and video-recorded.

Their finding will be particularly useful in understanding the process of rapid growth that the embryo undergoes after it is implanted.

Of mice and men

Studying the blastocysts of mice, Bedzhov and Zernicka-Goetz discovered how a blastocyst  develops from a ball of cells to the cup-shape seen during post-implantation. The cells of the ball-shaped blastocyst form into a rosette of wedge-shaped cells. 

While the researchers used reproductive cells from mice, the procedure carries across all mammals. The mouse blastocyst formed the rosette-shape on it’s fourth day, for humans this would likely occur after seven days.

Stages of mammalian reproduction

In mammals embryos develop in two main stages pre- and post- implantation. In the pre-implantation stage the embryo is a small ball of cells (known as a blastocyst ), “floating” around the uterus.In the post-implantation stage the blastocyst has attached itself to the uterine lining.

Until now it was only possible to grow a blastocyst outside the body for research up to the point of implantation. According to study author Professor Magdalena Zernicka-Goetz the post-implantation stage has been an enigma.

A great deal is known about the blastocyst during pre- and post-implantation. But  before today very little was known about the first two days of implantation (known as peri-implantation).

Thanks to the research done by Ivan Bedzhov and Magdalena Zernicka-Goetz at Cambridge University, not only has this mystery been solved, there is video proof, made publicly available thanks to EurekAlert.

Changing the textbooks

With this new discovery biology textbooks world-wide will need to be re-written. Professor Zernicka-Goetz explained that current texts only have educated guesses on this stage of blastocyst development.