摘要：In 1965, I was given the opportunity to manage a research animal colony. At that time, the animal colony consisted of numerous species, such as primates, dogs, cats, rab bits, guinea pigs, hamsters, rats, mice, and some farm animals as well. Over the years,this menagerie was reduced to mice and rab bits. The animal facility now houses 8 000mice, of which 80% are transgenics. In approximately six years, transgenic mice have become the mainstay of the Berkeley Lab animal facility, and this population continues to grow.