Scientists explore chicken genome to reduce animal testing

Cultured chicken cells and fertilised eggs could soon replace mice in a range of laboratory experiments, according to British scientists involved in a major new research project announced today.

Scientists, from Nottingham and Dundee Universities, UMIST and the Roslin Institute, are planning to put together a chicken 'gene catalogue' that will allow scientists to knock out individual genes in cultured chicken cells in order to help establish gene function.

The catalogue will be built using data collected for the project by US company, Incyte Genomics and could lead to a reduction in the number of gene function experiments carried out on transgenic mice. At the moment, such gene-function experiments can, in some circumstances, be expensive or awkward to carry out.

"Most chicken genes have equivalents in human beings, so using the chicken to identify what genes are for has a direct impact on our understanding of human biology," says Professor Cheryll Tickle from Dundee University.

The research team, based across the UK, hopes that for many gene-function experiments, chicken cell cultures and embryos will eventually prove to be better test subjects than laboratory mice. One of the most obvious advantages is that chicken embryos develop in an egg rather than in a mother, making it much more straightforward for scientists to manipulate the embryo and carry out investigations.

"Our lack of knowledge about the chicken genome has held back the chicken as a research resource, so we are please to be taking the first steps to understanding the function of the chicken genome," says Dr Dave Burt from the Roslin Institute. "In the scramble to sequence the genomes of various organisms, somewhere along the line the chicken was left out."

This project is the first major attempt to characterize the genome of any bird. The research may also help improve understanding of important areas of bird biology such as song, complex behaviour and evolution.

Contacts:
Professor Cheryll Tickle, University of Dundee
tel: 01382 345817, e-mail: c.a.tickle@dundee.ac.uk

Dr William Brown, University of Nottingham (Project leader)
tel: 0115 849 3244, e-mail: William.R.Brown@nottingham.ac.uk

Dr Stuart Wilson, UMIST
tel: 0161 200 8935, e-mail: s.a.wilson@umist.ac.uk

Dr Dave Burt, Roslin Institute
tel: 0131 527 4200, e-mail: dave.burt@bbsrc.ac.uk

Andrew McLaughlin, BBSRC Public Affairs
tel: +44 (0)1793 413 301, e-mail: Andrew.Mclaughlin@bbsrc.ac.uk

Meghan E. Lane, Incyte Genomics, Palo Alto, California, USA
tel: +1 650-621-8973, e-mail: mlane@incyte.com

Notes for editors
1. This project is funded by the UK government's Biotechnology and Biological Sciences Research Council (BBSRC) and will utilise the services of the private sector in obtaining sequencing information. Incyte Genomics Inc. has been awarded the contract for producing the Expressed Sequence Tag (EST) data that will be included in the database.
2. Collecting EST data is done through a complex series of procedures. When genes are active (being expressed), the cell is in the process of using genes as a code for producing proteins. By copying the genes that are being expressed, scientists can insert tags onto the gene that can be identified from the 1.2 billion base pairs (building blocks) of DNA in the chicken genome. Incyte will be scanning the entire chicken genome looking for more than half a million of these inserted ESTs in order to help the British researchers construct the EST database.
3. All of the cDNA clones produced during the project and associated information will be made available for research through the BBSRC-funded UK centre for functional genomics ARK-Genomics and HGMP at Hinxton. The chicken cDNA resource will also be used to construct DNA chips available for research from ARK-Genomics (http://www.ark-genomics.org/) for high-throughput gene expression studies.
4. Some of the main experimental opportunities offered by chicken cells come from a special type of cell known as DT40. These cells are derived from lymphocytes (cells from the chicken Bursa gland) and offer enormous potential to scientists for discovering the function of genes involved in a range of processes. This is because DT40 cells can be manipulated in the same way that scientists manipulate yeast. At present, the majority of gene function research is carried out using mouse embryos.
5. Chicken biology has already led to many discoveries of fundamental significance:

• chicken was the first vertebrate to be studied using genetic techniques after the re-discovery of Mendel's Laws,
• study of chicken tumours led to the discovery of retroviruses (eg.HIV) and oncogenes (genetic material that carries the ability to cause cancer)
• studies of chicken immune systems led to the identification of B cells and T Cells (white blood cells of fundamental importance to the immune system).
• Many important discoveries about the way vertebrate embryos develop have also been made using chickens.