While it may take years before widespread genetic testing changes humanity, animals are experiencing a difference today. According to Forbes, a single genetic test for breeding dairy cattle has almost completely replaced older pedigree tests in less than two years. Developed by Curtis Van Tessell at the USDA and performed by Illumina, this test costs only $250, replacing the previous system’s $50,000 price tag! The cheaper testing allows smaller dairy farmers to enter into the profitable business of selling cattle eggs and sperm. Using genetic testing, milk producers predict that the annual increase in US milk production will double to 5%. We’re talking about millions of dollars of increased profit in the United States alone. Van Tessell’s new test demonstrates that the age of widespread genetic evaluation has already started.
When it comes to human genetic testing, Illumina is one of the biggest names in the business. It and competitors like Complete Genomics are aiming to bring whole genome sequencing into the price range of most individuals. Right now, more affordable genetic evaluation can focus on key genes in human DNA. These single nucleotide polymorphisms (SNPs) are cheaper to test – companies like 23andMe use them exclusively to great avail. In Van Tessell’s test, SNP tests are used to keep track of 38,000 key differences that the USDA team discovered were important in dairy cattle breeding. One wonders how whole genome sequencing will affect animal husbandry. The bovine genome was recently mapped in 2009. Could we see even more profitable breeding? Maybe greater acceptance of germline genetic engineering? The reverse also could be interesting: how will attitudes about human genome testing change when genetic evaluation becomes a staple on the farm?
Funny enough, Illumina wasn’t really interested in getting into the animal testing business. Van Tessell was originally working with Solexa when that company was acquired by Illumina. He had to work tirelessly to convince the new company that his cattle evaluation was a worthwhile endeavor. Finally, Illumina developed a chip (snp 50) to use in Van Tessell’s test. It paid off for everyone. Illumina generates about $50 million a year, 8% of its revenue, through agricultural genetics, of which the cattle testing is a major contributor.
What exactly is the Van Tessell test looking at? A long history of milk production. The USDA Animal Improvement Programs Lab evaluates genetic fitness by examining milk records and certain cells in the udder. This helped the USDA and Van Tessell determine which 38,000 genetic markers would correspond to animals that not only had the best genes for milk production, but were actually passing those genes on to offspring. The last century of pedigrees were only about 30% accurate in finding good dairy cows. No pedigree can be better than 50% (due to uncertainty in which parent will pass on a particular gene). The new genetic test is about 70% accurate in predicting milk production. And again, it costs just $250!
With genetic benefits, however, come genetic concerns. In the past thirty years selective breeding has lead to a 8% increase in milk production per Hollstein cow. It has also generated a system by which only 500 bulls are used to inseminate nearly 9 million heifers. The new test has allowed smaller farms to enter into the sperm and eggs market, finding better breeding stock in previously unevaluated cattle. Yet of the 3000 bulls tested under the new system last year, only 130 qualified for breeding. It seems like the male side of the gene pool is going to stay pretty shallow. I worry about any living product (animal or plant) with a narrow family tree. It opens the way for a small genetic predisposition to a new disease to devastate an entire industry.
That won’t likely be a problem with humans however, and the genetic testing of cattle has some important implications for our own species. A single test is going to double the increase in production, and yield untold profits for milk farmers. What kind of parallel benefits might humans enjoy as genetic evaluation becomes more available? We’ve already seen how SNP testing can help tell you about your susceptibility to certain diseases. The real changes in humans, as with cattle, may come when genetic sequencing starts to affect breeding. People are already clamoring to evaluate their kids, and many may want to start the evaluation process earlier. Would you pay $250 to see if your prospective mate had a genome clear of defects? Some would. Some will. And while public discrimination based on genetics in now illegal in the US (and has been in other nations for some time), private discrimination is still to be determined. Are we going to pay a social/moral price for the profits of genetics? Van Tessell’s work with cows make those profits seem very high. In the next few years humanity may follow the herd.
[photo credit: ESPN]
