Transferring cattle genes


Jim Robl, president and CSO of Hematech LLC, describes the applications of transgenic technology to animal agriculture.
Cattle traditionally haven’t maintained a role in talks of human medicine, but that’s quickly changing. Transgenic technology is allowing researchers to produce human proteins in cattle — just one of the possible agricultural applications of the technology, said Jim Robl, president and CSO of Hematech LLC. Robl addressed the crowd during the first night of the 2004 Beef Improvement Federation (BIF) Annual Meeting in Sioux Falls, S.D.

Significant advancements during the last couple decades have allowed scientists to advance from simply using a needle to extract and transfer DNA to using more complicated methods of genetic manipulation and embryo cloning.

Robl said two types of genetic manipulation that have allowed the cattle industry to greatly enhance its efficiency are gene targeting and microchromosome transfer. In gene targeting, researchers are able to block out or replace unfavorable genes in one breed of cattle with those from another, without diluting genetic makeup or causing harmful mutations. A similar function, Microchromosome transfer involves the insertion of an entire sequence of DNA.

The technology, he explained, has two implications for the cattle industry— improved efficiency of food production and production of products such as pharmaceutical proteins for human medical needs.

Introducing transgenic beef into the marketplace carries a variety of considerations, he warns. First, regulatory agencies like the Food and Drug Administration (FDA) must deem the product safe for human consumption. Effect on the environment and animal welfare are other considerations, as well as poor cooperation among different sectors of the beef industry. Consumers and producers would need to accept the technology.

For the last five years, Hematech has been working on a collaborative effort to produce human antibodies in cattle that could be used to treat a wide variety of infections, help fight cancer cells, reduce organ transplant rejection, and fight autoimmune diseases.

Researchers inactivate certain bovine chromosomes using gene-targeting technology and attach human chromosome fragments. The resulting calves produce a low level of human antibodies.

The technology, Robl says, holds future implications for the beef industry.

“We’re now beyond transgenics and manipulating single genes. We’re now in an era of chromosome engineering.”

– by Crystal Albers