Sept. 24, 2007

COLLEGE STATION – A group of researchers – including Texas Agricultural Experiment Station scientists – have used gene fragments from Hereford, Holstein and Angus animals to create an artificial chromosome map. The artificial chromosome map will be used to study disease resistance or immunological response to vaccination, feed efficiency and reproductive efficiency in beef animals, said Dr. Clare Gill, Experiment Station associate professor.

The work was recently published in Genome Biology. It is significant for several reasons, said Gill, one of the authors.

"The result of the project is the densest marker map for cattle because it combines all of the marker resources in the public domain," she said. Markers are short sequences that are inherited and have similar sequences between animals within the same species.

The project also provided order for the bacterial artificial chromosomes used in the sequence assembly process. The bacterial artificial chromosomes were fingerprinted to identify which ones would overlap, Gill said. The ones that overlapped were arranged in order from one end of a chromosome to the other.

The project also put the bacterial artificial chromosome maps immediately into the public domain so individual researchers could focus on specific regions of the genome, she said.

In this project, a bovine bacterial artificial chromosome map – fragments of DNA that are cloned or copied – from Hereford, Holstein and Angus cattle were used.

The Angus bacterial artificial chromosome map was created from the DNA of a bull at the Experiment Station in Angleton, Gill said.

The Genome Biology article detailing the project is located at http://genomebiology.com/2007/8/8/R165 .

The first assembly of the cattle genome sequence was released in 2004. The Human Genome Sequencing Center at Baylor College of Medicine was the leader in that project.