September 26, 2014

Coordination in the spinal cord

IST Austria Professor Tobias Bollenbach together with colleagues Anna Kicheva and James Briscoe at the London-based National Institute for Medical Research (NIMR) has uncovered how the production of different types of neural cells and the growth of the embryonic spinal cord are coordinated.

The development of embryos requires the production of new cells with specific identities and functions. How does a growing tissue establish and then maintain the right proportions of different cell types? In a study published in today’s issue of Science (DOI: 10.1126/science.1254927), Kicheva et al. address this longstanding question.

The study reveals that different mechanisms are employed during two distinct phases of spinal cord development. Initially, morphogen gradients – long range signals that partition the tissue into domains of distinct cell types – establish the pattern and proportion of different cell types. During the second phase the growth of these domains is controlled by the speed at which progenitor cells differentiate to become neurons. It is this regulation of differentiation rate that appears to account for the domain proportions and accommodate variations in size.

First author Anna Kicheva: “The use of quantitative methods has allowed us to measure, for the first time, how the number of each type of neural progenitor in the spinal cord changes during embryonic development. Our data reveal that the proportions of different cell types are controlled using different mechanisms at different developmental times and that the rate of differentiation is key to explain the final pattern.”

James Briscoe: “The study provides new insight into the long standing question of how growth is coordinated with the production of different types of cells in developing tissues. It’s likely that similar strategies are used in other developing tissues and our findings might be relevant to these cases, as well as help inform tissue engineering approaches.”

Tobias Bollenbach: “This work addresses how the proportions of different cell types are established in animal development using the neural tube as a model system. In the long term, quantitative experimental studies of this type in combination with theoretical modeling and statistical analysis will help elucidate the cellular mechanisms of tissue patterning in development.”

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