US-AUSTRALIAN ACADEMIES JOINT WORKSHOP
US-AUSTRALIAN ACADEMIES JOINT WORKSHOP ON VERTEBRATE COMPARATIVE GENOMICS
Beckman Conference Centre, Irvine, California, 23-25 May 2007
Applications of comparative genomics to bovidae
by Cindy Bottema
Dr Bottema received her PhD in Microbial Physiology at Oregon State University. Upon completion of a post-doctoral fellowship at Stanford University, Dr. Bottema was appointed as a human molecular genetics research associate at the Mayo Clinic. In 1992, Dr. Bottema took a position at the University of Adelaide as the JS Davies Professorial Research Fellow in cattle molecular genetics. In 2000, Dr Bottema became a tenured academic at the University of Adelaide. As a member of the Cooperative Research Centre for Beef Functional Genomics and as a consultant for SheepGenomics, Dr Bottema continues to pursue an interest in the genes controlling cattle and sheep traits and in Bovidae genome evolution.
Comparative genomics has led to significant progress in the understanding of the genetic architecture of those species whose genomes have not been sequenced or not fully annotated. It also allows genetic inferences to be drawn between closely related species, such as cattle and sheep. Examples of such progress in cattle and sheep in our group include the delineation of genome evolution, the characterisation of pseudogenes, the localisation of genes, and the identification of sequence polymorphisms controlling traits of interest.
We have used our ovine BAC library to sequence and physically map a number of genes in cattle, sheep and goats for a range of collaborative projects. This has particularly aided the discovery of functional DNA variants. For example, the causative mutation of the spider lamb syndrome was found by the comparative mapping of the fibroblast growth factor receptor 3 gene. In other cases, comparative mapping has re-directed the search for candidate genes. This was illustrated by the physical mapping of the ovine stearoyl CoA desaturase (SCD) gene, which demonstrated that, unlike cattle, SCD does not affect fatty acid composition in Texel and Coopworth sheep.
Physical mapping and sequence comparison has also allowed us to tackle questions regarding chromosomal abnormalities and evolution. We have demonstrated, for instance, that while more recent Robertsonian translocations in cattle and sheep are dicentric, the centromeres of sheep resulting from ancient Bovidae centric fusions have lost satellite repeat sequences and consequently, are monocentric. The centromere in the Robertsonian (1;29) translocation in cattle is also monocentric, suggesting this specific translocation may pre-date domestication.
It can be the subtle clues provided by molecular information from other species or direct genome comparisons between species that leads to such scientific discoveries. However, the speed with which these discoveries are made relies entirely upon the availability of molecular technologies, genome sequence data, and bioinformatics.
Contact details:
Discipline of Agricultural and Animal Science
Roseworthy Campus, University of Adelaide
Roseworthy, SA 5371 Australia
Phone: 618-8303-7641
Fax: 618-8303-7689
Email: cynthia.bottema@adelaide.edu.au
