The versatility and utility of the domestic chicken as a developmental model was recently celebrated in a special issue of the journal Developmental Dynamics [(2004) 229, 413-712.] The chicken is one of the primary models for vertebrate developmental biology and a model organism for the study of virology, immunology, cancer and gene regulation (Tickle, 2004; Antin and Konieczka, 2005). With a 6.6X draft sequence of its genome completed, the chicken is poised to become even more valuable in traditional fields of study and also in aging research.
The earliest recorded descriptions of the chicken as a model for biological processes are attributed to Hippocrates and Aristotle who both wrote about embryonic development in fertilized chicken eggs. Twentieth century embryologists authored numerous treatises describing, diagramming, and providing detailed photographs of the chicken during development (Hamburger and Hamilton, 1951; Romanoff, 1960; Eyal-Giladi and Kochev, 1976) which promoted use of the chicken embryo as a model for study of mechanisms including morphogenesis; neurogenesis; somatogenesis; limb, limb-digit and craniofacial development; left-right symmetry; axis development and others. The extensive use of the chicken as a model for early vertebrate development and its role in biomedical research has of necessity produced a detailed and comprehensive body of knowledge about basic chicken biology (Stern, 2005; Scanes et al., 2004). Add to all of this the accessibility of the chicken embryo, the relative economy of breeding and maintaining chickens and the ease of manipulation of embryonic and adult tissues and the chicken becomes an obvious choice as a model for the study of organismal and cellular senescence.