Science: Refugee Rats

“Please keep the rats for us. Our laboratory is situated near the big railway termini which will be among the first targets for raiding airplanes and we would like to be sure that some of the most important of our scientific materials are out of harm’s way. . . .”

So wrote a British zoologist during the recent European crisis to Dr. Leslie Clarence Dunn, professor of zoology at Columbia University. So across the Atlantic, to the enviable security of the U. S., voyaged eleven black, smooth-haired rats.

Their importance to science is that they have a unique hereditary defect of the sort which crops out occasionally in nature but which human investigators cannot produce at will. Some disturbance in the rat chromosomes (heredity carriers in the germ plasm) prevents their soft, prenatal cartilage from developing into a normal skeleton. The young appear normal for two weeks, then become bandy-legged as if suffering from rickets. Usually they die at the age of four to five weeks, with soft, collapsed ribs and emphysema of the lungs (air leakage into the spaces of the connective tissue).

The strain can be perpetuated because, according to the Mendelian three-to-one ratio, only one in four of the young rats manifests the lethal defect. Four of the females littered last week, and the colony now numbers about 30. Since zoologists by studying such anomalies can cast more light on the mystery of heredity transmission in the chromosomes, several U. S. scientists have expressed great interest in Dr. Dunn’s new boarders. He plans soon to ship specimens to other laboratories.

One well-established fact of genetic science is that certain characteristics tend to be transmitted in groups. In Dr. Dunn’s rats, for example, all of the soft-skeletoned individuals also have pink eyes.

Last year, long before the recent war scare, Dr. Dunn received from England a consignment of mice with a hereditary defect. Their teeth grew backward into their jaws, causing early death from malnutrition. Reason for this shipment was the same: fear of destruction by bombs.

“Perhaps,” says Dr. Dunn in the current issue of Columbia’s Independent Journal, “it will be necessary to establish a central haven for the threatened stocks of scientifically useful animals and plants from all nations. Perhaps it should be as far as possible from a seacoast and remote from the danger of air attacks. Perhaps it should be near that hole in the ground in Kentucky where we keep our spare gold.”