Germ Cell, Stem Cell, and Genomic Modification in Birds

Abstract

Germ cells are the only type of cell that can transmit all genomic information to the next generation. Such cells have unique characteristics, being not only germline-competent but also serving as stem cells. In Caenorhabditis elegansand Drosophila, germ cell lineages are predetermined. In contrast, in mammals, primordial germ cells, which are precursors of germ cells, are induced from multipotent epiblasts via extra-embryonic signaling. In avian species, however, the means by which germ cells are defined remain to be elucidated. Manipulation of germ cells is valuable in studies on germline development and in production of valuable cell lines. In birds, which lack germline-competent stem cells, genomic modulation of germ cells might serve to generate genetically modified poultry for both commercial applications and basic research.