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
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
- 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.