Model Organisms for Biomedical Research
Trans-NIH Gallus Initiative  

Major Resources
Courses & Scientific Meetings
Reports and Publications

The domesticated chicken is the premier non-mammalian research model organism. Research using chicken has been responsible for critical discoveries in development, virology, immunology, oncology, genetics and evolution. The chicken research community is diverse, reflecting the value of the chicken as a model not only for biological research but also as a major agricultural species.  Recent elucidation of the complete chicken genome sequence and development of genetic manipulation techniques have only increased its usefulness as a model.  This website provides a central information resource for NIH support of genomic initiatives for research on chickens and other bird species, plus links to community resources, meetings and publications. 

Characteristics and Advantages:

  • Sequencing of the chicken genome has yielded a high quality assembly of 1.2 gb organized in 39 chromosome pairs. The nearly threefold difference in size between the chicken and mammalian genomes reflects a substantial reduction in interspersed repeat content, pseudogenes and segmental duplications. The existing assembly already provides a very high quality draft, and NIH-supported efforts to bring this to a near-finished stage are underway.
  • The chicken is evolutionarily placed to bridge the gap between mammals and non-amniote vertebrates, and is by far the best studied representative of all avian species, thus providing a valuable genomic resource for comparative genomics.
  • Embryonic development an easily be accessed and manipulated in the chicken, thus explaining its historic important as an embryological model.
  • Almost 3 million SNPs have been identified between the base (wild type) red jungle fowl sequence assembly and a partial scan of three chicken breeds (layer, broiler and Silkie), demonstrating a remarkable genetic diversity even within selected commercial breeds.
  • A large number of genomic resources and tools are available, including sequence assemblies, SNP databases, linkage maps, microarrays, tiling arrays, QTL studies, annotation and gene expression databases, and techniques for over expression and knockdown of genes that can be precisely targeted in the chicken embryo .
  • Hundreds of well-characterized mutant stocks and inbred chicken lines have been developed.
  • Transgenics have been generated using both retroviral vectors and embryonic stem cells.
  • Landmark contributions from research using chickens include the first retrovirus, demonstration of Mendelian genetics in vertebrates, oncogenesis, mechanisms of recombination, immunology, the molecular basis of vertebrate morphogenesis and pattern formation.
  • A comprehensive body of literature spans more than 100 years.
  • The chicken is an ideal model for QTL analysis, with over 1500 QTL mapped. Commercial populations run into the billions, fueling interest in, and enabling, quantitative genetics in the chicken. Furthermore, the chicken is unique among major agricultural species in that a number of highly inbred lines are available.
  • A large international research community is dedicated to developing and sharing genomic resources.


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