Germ-cell attraction

摘要

All sexually reproducing organisms are composed of two types of cells: the 'mortal' somatic cells, which form the body of the organism, and the 'immortal' germ cells, which produce the next generation. During development, precursor germ cells (better known as primordial germ cells, PGCs) are created in one part of the embryo, often far away from their final destination. They must then migrate to the somatic part of the future gonads, where they become mature germ cells―sperm or eggs. Genetic analyses of fruitflies, zebrafish and mice have led to the identification of several genes that are required for PGC migration. Moreover, these studies have suggested that the somatic tissues that line the migratory path provide attractive, repulsive and survival cues that direct the germ-cell precursors. Such cues have so far proved elusive. But, writing respectively in Cell and on page 279 of this issue, Doitsidou et al. and Knaut et al. show that a pair of evolutionary conserved molecules― the protein SDF-1 and its receptor CXCR4―act to guide PGCs in zebrafish.