Kunwar et al. survey the embryonic development of three animals – Drosophilia, Zebrafish and Mouse – and highlight some clear and general emerging concepts that characterize germ cell migration, despite differences in origin of this cell type. They emphasize commonalities such as: how balanced intrinsic and extrinsic factors control initiation and termination of migration; the role of G Protein-coupled receptor (GPCR) activation in germ cell directionality; and the balance of attractive and repellant cues which provide efficacy and consistency to the migratory route.
On the signal transduction side of things, the GPCR note caught my attention, as well as the authors’, who note that GPCR orient other cell migration behaviors as well – leukocytes in the inflammatory response, in particular, but Dictyostelium and some cancer cells also – primitaive amoeboid migration. These cells move individually with a broad leading edge, highly dynamic morphology, and low adhesiveness; differing from fibroblasts, neural crest cells, border cells, and gastrulating cells. Even in these cases, however, the roles of chemokines and phospholipids as orienting cues is a common feature shared by both amoeboid and nonamoeboid cells.
Further, germ cells also show similarities to leukocytes and some cancer cells (e.g. those involved in lymphoma, leukemia, and small-cell lung carcinoma) in their ability to migrate through epithelial and endothelial cell layers in diverse tissues to an ectopic organ destination.
Evo-Devo on the cellular level. Neat.
- In Vivo Migration: A Germ Cell Perspective. Kunwar PS, Siekhaus DE, Lehmann R. Annu Rev Cell Dev Biol. 2006 Jun 14; [Epub ahead of print] Pubmed.