Abstract
To improve the take-rate of human tumours in nude mice, a nude mouse strain with the bg gene was established. The introduction of the bg gene was confirmed by examination of giant granules of blood neutrophils. The genetic profile of beige–nude mice was the same as that of the C57BL/6 strain according to genetic screening. The natural killer cell activity in the beige–nude mice was much lower than that in ordinary nude mice but slightly higher than that in beige mice. The reproductivity of beige–nude mice was as high as that of ordinary nude mice.