Avian biotechnology: Insights from germ cell-mediated transgenic systems

Aves species have become valuable models for numerous experimental and biotechnological purposes due to their unique embryological and physiological traits. This review integrates recent progress and new insights into the molecular and physiological mechanisms of transgenic fowl production. Recent reports have indicated that birds are essential for studying vertebrate development and the conservation of endangered bird species, as well as serving as bioreactor hens. Over the last decade, germ cells and genetic modification have become pivotal components for the production of transgenic animals. Three prerequisites must be met for successfully producing transgenic fowl: the effective manipulation of various types of avian pluripotent cells without the loss of differentiation capacity, the manipulation of genes of interest without altering normal gene function, and increasing the efficiency of germ line chimera production. An understanding of the cellular and molecular signals that regulate germ cells as well as the development of a stable gene delivery method will make these species in-dispensable tools for basic research and biotechnological applications.