FROM BEEF CRC BULLETIN DECEMBER 2006

BRAHMAN NEWS SEPTEMBER 2007 Issue #156

Professor John Gibson, 
leader of the Beef CRC’s Research Program 3: Adaptation and Cattle Welfare

By 2010 the Beef CRC anticipates cattle breeders may be able to get an accurate assessment of a bull or a dam’s future performance within a few months of its birth.

The technology to bring this revolution to life has already been developed and Beef CRC scientists will now test whether it can become a commercial tool for the Australian beef industry.

Professor John Gibson, leader of the Beef CRC’s Research Program 3: Adaptation and Cattle Welfare, said existing microarray technology allowed researchers to measure gene expression (how strongly a gene functions within an animal) on thousands of genes simultaneously.

In fact, the technology means that the entire 23,000-odd separate genes of the bovine genome can now be printed on one microarray plate the size of a microscope slide.

The process allows all the genes of two animals to be quickly compared, so that scientists can swiftly determine genetic differences. Over numerous microassays, a picture can be readily established of where the genes of different animals vary from the species norm.

All this is a radical leap from the process that Beef CRC researchers have been using to date, which involves teasing out the value of genes one-by-one, within herds that are carefully structured to highlight potential differences in gene expression.

Professor Gibson believes that microarray technology potentially offers twofold benefits to beef producers.

The first is the prospect that it will speed up the Beef CRC’s genetic work to previously undreamed-of levels.

“Much of the Beef CRC’s work involves looking at the inheritance of different genes using molecular markers,” Prof. Gibson said. “We’ve operated on the premise that how well an animal expresses a gene, for example how well that gene functions, depends largely on what version of the gene the animal inherits.”

“We can predict that if an animal inherits a certain copy of a gene, it will perform better or worse. But using traditional methods to get to this point is a long and tedious process.”

“With microarray technology, we think that it may not be necessary to establish which copy of a gene an animal has.”

“Because we have an overview of gene expression across the entire genome, and can see which genes are important for changing certain traits, we can instead just look at how an animal’s genes are functioning without being concerned about tracking down the individual gene type.”

This ability to get a full genetic overview of an animal could eventually lead to the grassroots application of microarray technology, Prof. Gibson says.

…this (technology) would help breeders quickly eliminate genetically inferior bulls and cows without the costs of feeding and progeny testing now required…

Work done overseas indicates that how an animal expresses its genes in early life provides an accurate picture of its gene expression at breeding age.

This leads to the prospect that microarrays could be produced that carry genes of commercial interest, which could then be used to predict the breeding performance of young animals, well before they reach breeding age.

Prof. Gibson observes that this would help breeders quickly eliminate genetically inferior bulls and cows early in their life, without the costs of feeding and progeny testing now required to determine the duds.

It could also encourage the industry to join bulls at a younger age, speeding up genetic progress.

“If the cost of the technology becomes cheap enough – and there’s every possibility that it could – it would even be possible to test animals before they went into a feedlot, to see whether genetically, they were worth feeding and would deliver a return on investment.”

The catch?

“At the moment, it’s all blue sky stuff,” Prof. Gibson says.

“But the Beef CRC will be doing a small, lowcost pilot study on the technology in mid-2007, and that should give us a proof of principle. If that looks promising, we’ll immediately follow up with some wider testing.”

“We would hope that by the end of the current Beef CRC, we’ll know whether we have a product that is useful for the commercial beef industry.”