Science: Mouse Hunt

All over the U.S. last week scientists were hunting mice. The search was on for brown mice, white mice, yellow mice, mice with hairless skins and mice with peculiar, deformed tails. The leading U.S. mouse pool had been destroyed.

When the Roscoe B. Jackson Memorial Laboratory at Bar Harbor, Me., was gutted by forest fire three weeks ago (TIME, Nov. 3), some 90,000 pedigreed breeding mice were caught in the flames. They represented 30 carefully bred strains, each with special qualities. Some were valuable because they were susceptible to polio, others were prone to nervous crises. Certain yellow mice (which grow fat with age) were used in the study of fatty (liposarcoma) cancers. Certain long-cherished strains were used in educational institutions all over the country to illustrate the Mendelian laws of inheritance.

After the blackened buildings cooled, Director Clarence Cook Little walked sadly among the cages of roasted or suffocated mice. A few “little fellows” looked up with frightened eyes, among them two elderly, fat yellow mice. But survivors were few. Out of the 90,000, only 55 were alive.

The mouse holocaust was a major disaster to researchers in medicine and biology. The Jackson Memorial Laboratory, though primarily devoted to biological research, had been for years the leading source of experimental mice. Last year it shipped 350,000 to U.S. and foreign researchers. Deprived of the Bar Harbor strains, many researchers will have to start their laborious work all over again. To a researcher, a pedigreed mouse is a precision instrument. No ordinary mouse, nor a mouse of another strain, can be expected to react in exactly the same way.

Last week Dr. Little was hopeful; his scientist customers were rallying round, offering breeding stock from descendants of mice he had once shipped to them. In a year or so, he hopes, he will have all the most important strains, housed this time in improved, fireproof buildings. He still lacks a few strains (notably C57 brown, sub-line C and C57 brown, sub-line A, used chiefly for breast cancer research). Many of the strains used to illustrate Mendelian laws are also missing. Dr. Little thinks that the missing mice strains may yet be found in some small laboratory, or maybe even in a high school. He hopes that their owners will be generous.