Editing Germ cell (section)

===Invertebrates===
In the [[model organism]] ''[[Drosophila]]'', pole cells passively move from the [[anatomical terms of location#Anterior and posterior|posterior]] end of the embryo to the posterior midgut because of the infolding of the blastoderm. Then they actively move through the gut into the [[mesoderm]]. [[Endoderm]]al cells differentiate and together with Wunen proteins they induce the migration through the gut. Wunen proteins are [[chemorepellent]]s that lead the germ cells away from the endoderm and into the mesoderm. After splitting into two populations, the germ cells continue migrating laterally and in parallel until they reach the gonads. Columbus proteins, [[chemoattractant]]s, stimulate the migration in the gonadal mesoderm.{{citation needed|date=December 2011}}