Field Museum gets a new superstar

The skeleton of Clint, whose blood was used to map the chimp genome, will be safeguarded here for future research By William Mullen Tribune staff reporter

Published September 6, 2005

Clint the chimp, whose scientific stardom was assured when researchers announced last week that they had mapped out the chimpanzee genome using his blood sample, is a resident of Chicago. At least, what remains of him resides here. Before Clint could bask in the glory of his fame, he died of heart failure last year at age 24

. Upon learning of his death, a biological anthropologist at the Field Museum lobbied to bring the chimp's skeleton to Chicago. In acquiring Clint's bones, Robert Martin hoped to set a pattern for when the genes of other primate species are cataloged in the future. It is important, he said, to preserve the skeleton of the donor animals as "voucher" specimens. "I have been pushing this idea for some time," said Martin, who also is an adviser to Integrated Primate Biomaterials and Information Resources, a federally funded repository that cryogenically stores DNA from non-human primates. Such genetic material, extremely difficult to obtain in the past, will be available to researchers through the repository.

One reason to keep skeletal remains of animals used to sequence genomes is that people can make mistakes, Martin said. The voucher specimen can help answer any questions that might arise. "Secondly," he said, "new knowledge can change the picture of your baseline data. For instance, the common chimp until very recent years was considered to be one single species throughout Africa. Now there is a suspicion that there are two or three distinct species of chimps around the continent. "If that is confirmed, one day we want to go back to see which species Clint belonged to, so that his information isn't used for an entirely different species we haven't yet recognized."

Five or six years ago, when Clint was living at Yerkes Primate Center in Atlanta, the staff took a routine sample of his blood. That sample was divvied up and distributed to genetic researchers around the world, members of a consortium organized to map the chimpanzee genome, similar to the mapping of the human genome that was completed two years ago.

Last Wednesday those scientists announced the completion of the chimp genome in an article published in the journal Nature. It was a widely anticipated, much heralded achievement, and the catalog of Clint's genetic makeup likely will be the fodder of countless research projects in the decades to come. By studying the genetic differences between humans and their closest relatives, the chimps, scientists hope to gain insight into such mysteries as the evolution of the human brain and the origin of diseases.

After Clint's death and following his post-mortem at Yerkes, the Field Museum had his remains delivered to Chicago. Martin, whose career has been centered on studying the evolution of primates, took a genetic sample from the body before it was put in the museum "bug room," where carcasses are efficiently reduced to skeletons. The Integrated Primate Biomaterials and Information Resource, which Martin help found, so far has cryogenically preserved genetic material from about 100 of the approximately 350 primate species recognized in science.

The material is usually collected from primates in laboratory and zoo populations, though it is also occasionally taken from wild animals. The process does not injure the donor animals. The material collected by the repository--blood, connective tissue--is stored at at least minus 80 degrees Celsius at the Coriell Institute for Medical Research in Camden, N.J. An identical repository as a backup is kept at the San Diego Zoological Society's Center for Research on Endangered Species. "We have the frozen zoo," said Oliver Ryder, head of San Diego's genetics division, which for 25 years has been collecting and preserving DNA samples from all manner of species, not just primates. "This would not have been possible without collaboration of 70 zoos around the country. We're one of the few institutions banking cell cultures. We have been establishing cell cultures for 30 years from 7,200 individual animals representing 650 species coming from at least 200 institutions. It is an irreplaceable resource."

Martin said that, ideally, the skeleton of the animals should be saved after their death. Because the samples are often taken from young animals, institutions should keep track of them so their remains can eventually be preserved, he said. He is urging museums like the Field to volunteer space and effort in preserving remains.

Eventually, the hope is to have the complete genome map of every primate species because of their value in studying human evolution and disease processes. It took 13 years to map the human genome but just two years to map the chimp genome from Clint's samples once the work got under way in 2003, said Richard Wilson, a genetics professor at Washington University in St. Louis who participated in the chimp project.

Other primate genomes will be described even more quickly, he said. "That is how much the technology improved," Wilson said. "When we were sequencing 20 years ago, it was a few hundred base pairs [of DNA] a week. Now we can sequence a few billion a month."