Genome code on Jackson Lab mice broken Sequencing of ‘Black 6’ strain could mirror human genetics

WASHINGTON – Mice from Bar Harbor’s internationally acclaimed Jackson Laboratory took center stage Tuesday as scientists announced continued success in closely identifying the genetic mapping of the lab’s most famous mouse strain, the “Black 6.”

Laboratory mice are the most widely used animal model in the study of human diseases and development, and the $130 million Mouse Genome Project represents a landmark advance for the pioneering Human Genome Project. The research shows that the biological similarities between mice and people are even more striking than believed before. By comparing the genetic makeup, or genome, of mice and men scientists hope to unlock the mysteries of cancer and other complex diseases.

“It constitutes a tremendously exciting and defining moment for biomedical research,” said Dr. Francis Collins, director of the National Human Genome Research Institute, who noted that this is the first time that scientists have compared and contrasted the contents of the human genome with any other animal.

“It powerfully magnifies our understanding of the animal we know best – ourselves,” he said at a morning news conference at the National Press Club where he joined others in releasing a detailed draft sequence of the mouse genome. An analysis of the nearly completed genetic blueprint was also published in the latest issue of the journal Nature being released today.

The detailed findings, recorded on a database at the Massachusetts Institute of Technology, will give a big boost to pharmaceutical firms researching treatments for human diseases because it will reduce the time it takes to develop and test new products, said Dr. Richard P. Woychik, who recently became director of Jackson Laboratory.

“Now that we have the template for the mouse, the timelines for biomedical research will be vastly accelerated,” Woychik said. “Investigators can put on their lab coats and safety glasses and sit around a keyboard to do real experimentation rather than having to sit at a laboratory bench and do their own sequencing.”

Other scientists at the news conference said 96 percent of the mouse genome has now been identified and that 40 to 50 percent of that sequence mirrors the human makeup. More than 90 percent of the genes associated with disease are identical in mice and humans, they said.

Dr. Eric Lander, director of the Whitehead Institute, compared genome sequencing to a book of genetic instructions and codes and said that humans and mice share much of the same information.

“They have essentially the same chapters, but in different orders and more than half the sentences are the same,” Lander said. “So there’s a lot more there in the genome than we have realized.”

The findings also represent a great leap forward for researchers at Jackson Lab, according to Joyce Peterson, public information manager for the lab.

“This is not just a better dictionary; it’s like waking up one morning and being bilingual,” she said.

The Genome Research Institute leads the Human Genome Project for the National Institutes of Health. A dozen genome sequencing centers in the United States and Great Britain contributed data on the mouse, including the Whitehead Institute/MIT Center for Genome Research in Cambridge, Mass., one of the largest genome centers in the world.

The Black 6 mouse strain, first developed in the early 1920s by Jackson Laboratory founder Clarence Cook Little, was used for the sequencing.

Founded in 1929, the Bar Harbor Laboratory is home to 37 research units and 750,000 mice at any given time.

Medical projects at the lab include research into cancer, aging, the immune system, sensory disorders, metabolic diseases and blood disorders.

The publicly supported, nonprofit lab also operates several facilities in California and breeds 3,500 different strains of mice, selling 2,700 of the strains commercially to the scientific community around the world.

In 2001, the lab distributed 1.9 million mice – estimated to be valued at $40 million, according to Peterson.

Twenty mice of the lab’s Black 6 strain, technically known as the C57BL/6J, were used by scientists for the genome sequencing.

While selection of a mouse strain for genome sequencing was competitive, “the choice was quite straight forward,” said Dr. Robert Waterson, co-director of the Genome Sequencing Center at Washington University in St. Louis. “The Black 6 is the most widely used for research by scientists.”

The Black 6 is also widely regarded for being genetically identical from one generation to another and research records on the mouse go back decades.

“Each strain of mice is like an unlimited number of identical twins and that’s the reason why mice are so popular,” said Woychik. “They are genetically the same and we know where every mouse came from. So for the mouse that donated it’s DNA to the sequencing project, we know when it was born and who its parents were.”

Scientists generally agree that mice and humans share a common evolutionary ancestry that diverged some 75 million years ago.

Using mice as a model for biomedical research dates back to the start of human civilization. Ancient Chinese references have been found that refer to mice being first selectively bred to create albino, yellow and even waltzing strains.

When the Human Genome Project was first established in 1990 it included the mouse as one of its five central model organisms for study with the mouse being targeted for the creation of genetic, physical and sequence mapping of its genomes. Scientists are also working on mapping the genes of the rat, dog, chimpanzee and cow.