Kazuko Hanyu-Nakamura and colleagues in the RIKEN Center for Developmental Biology Laboratory for Germline Development (Akira Nakamura, Team Leader; Kobe, Japan) have fit a new piece into this jigsaw with findings recently published in the online edition of Development , describing an intriguing new model of germ cell migration involving a pair of guidance molecules, Wunen and Wunen2, and their discrete activities in germ and somatic cells.
The study began with a screen for mutant flies, which uncovered a phenotype in which the flies' primordial germ cells, called "pole cells," showed defects during their migration: the pole cells died in large numbers at a stage when they would normally begin to associate with the gonadal mesoderm. The genetic deficiency responsible for the defect was identified as a maternal effect mutation, meaning that its function (or loss of function) relies entirely on transmission by the mother fly. A closer analysis of the failing pole cells indicated that they began their development and migration normally, and that their deaths did not display a significant increase in the molecular activity most commonly associated with programmed cell death activation of
Contact: Doug Sipp
RIKEN Center for Developmental Biology