PhD Graduation Ben Nelemans (VUmc): How to Build a Spine? Exploring Machanobiology of Somite Formation in the Chicken Embryo
23-10-2018 15:45 23-10-2018 17:15 Aula | Main Building | VU Campus

About Ben Nelemans
Ben Nelemans studied biology at Leiden University, where obtained his master's degree in Animal Biology, specializing in embryology of reptiles and birds. Since 2018 he works as a University Lecturer at Utrecht University, teaching developmental biology.

Promotor: Prof.dr.ir. T.H. Smit

How do tissues develop? How does stem cell differentiation work? These questions are of great importance to gain more insight into healing processes of wounds, but also of diseases such as cancer.

The focus of the research was on the physical formation of somites. Somites are the cellular blocks that form the basis of vertebrae in the young embryos of all vertebrates, including in humans. From existing literature, it was known that the development of the somites is driven by certain genes, which are activated via chemical signals. In this research, Ben Nelemans of Amsterdam Movement Sciences studied whether mechanical stimuli can influence or control the development of somites.

While experimenting with the mechanical conditions of the chicken embryo, the somites can be reorganized into two or more so-called 'daughter-somites'. This shows that the cells in the somites can respond to mechanical changes in their environment and that they themselves control their formation: self-organization. This suggests that the developmental origin of the spine is regulated by a combination of biochemical and mechanical signals and might be more flexible than thought before.

As the somites take a different form when their mechanical environment varies, it will be interesting in the future to study if this trait contributes to the evolution of the large variation in the number of vertebrae between vertebrates; the construction plan of vertebrates.

Mechanical stimuli and spine development

To study this early developmental process, we have bred chicken embryos outside the egg in a self-developed system in which the chicken embryo can be slowly stretched along the head-tail axis. In this way, we were able to exert stretching forces on the undifferentiated cells during their development into somites.

When we better understand the mechanisms underlying physical somite formation, this can also contribute to a more detailed understanding of tissue development and stem cell differentiation. That is valuable in the future for identifying causes of various congenital disorders, to make new organs and tissues for transplants. In addition, somite formation has common grounds with the spreading of cancer cells in the body and the processes during wound healing.

Link thesis library: http://dare.ubvu.vu.nl/handle/1871/55787