Determination of pH regulatory abilities in primary mesenchyme cells using pH-sensitive dyes in combination with the ammonia pulse technique.

Efficient pH regulation is a fundamental requisite of all calcifying systems in animals and plants. Protons generated during biomineralization need to be buffered and excreted to promote further precipitation of CaCO₃. The calcite endoskeleton of the sea urchin larva is formed through intracelllar precipitation of amorphous calcium carbonate within vesicles of the primary mesenchyme cells (PMCs). To date, little is known about pH regulatory mechanisms of PMCs which represents an important aspect to understand biomineralization.

My research uses a wide range of methods ranging from life imaging over immunohistology to molecular techniques including in situ hybridization, gene knock-down and functional genomics to identify pH regulator systems in PMCs. Although the sea urchin larva has been studied by embryologists since over a century, pH regulation remains largely unknown. pH regulatory mechanisms including H⁺ and HCO₃^– transport pathways affect the calcification process in different ways: i) HCO₃^– transport supplies the cell with substrate for the precipitation of CaCO₃ and ii) the regulation of intracellular H⁺ and HCO₃^– homeostasis is critical to buffer and remove excess protons generated by the intracellular precipitation of CaCO₃.