Goudarzi, M., Strate, I., Paksa, A., Lagendijk, A.K., Bakkers, J., and Raz, E. (2013) On the robustness of germ cell migration and microRNA-mediated regulation of chemokine signaling. Nature Genetics. 45(11):1264-1265.
Zebrafish primordial germ cells (PGCs) migrate toward the site where the gonad develops from four starting points that are randomly positioned with respect to the embryonic axis. This migration is guided by Sdf1a signals provided by the somatic environment that are perceived by the Cxcr4b receptors expressed on germ cells. The high fidelity of migration is reflected by the fact that, despite concurrent extensive morphogenetic movements, virtually all migrating cells reach their target by the end of the first day of development. Furthermore, similar to many other processes in embryogenesis, the arrival of germ cells at their target appears to withstand environmental perturbations (for example, a range of temperatures) and to be unaffected by genetic variation (for example, differences in genetic background and severe developmental mutations) and, hence, can be considered robust.