DOI QR코드

DOI QR Code

ENHANCEMENT OF NORMAL AND NEOPLASTIC MAMMARY GROWTH BY CROSSBREEDING BETWEEN STRAINS OF FEMALE AND MALE MICE WITH HIGH MAMMARY GROWTH POTENTIALS

  • Nagasawa, Hiroshi (Animal Breeding and Experimental Animal Research Laboratory, Meiji University) ;
  • Koshimizu, U. (Research In stitute for Microbial Diseases, Osaka University) ;
  • Yamamoto, K. (Department of Biology, School of Education, Waseda University)
  • Received : 1988.01.08
  • Accepted : 1988.03.14
  • Published : 1988.03.01

Abstract

Based on our previous results that among 4 strains of mice SHN and GR/A showed the highest mammary growth potentials in females and males, respectively. Effects of crossbreeding on normal and neoplastic mammary growth were studied in $(SHN\;{\times}\;GR/A)F_1$ virgin female mice. $F_1$ mice were higher than the parental strains in the end-bud formation and the ductal growth of mammary glands at 60 days of age and at tumorous age, respectively. While there was little difference between $F_1$ and both parental strains in the onset age of the first mammary tumors, mammary tumorigenic potential was apparently higher in the former than in the latters. This would be the first report that demonstrated directly the contribution of mammary growth potential of males to that of female offspring.

Keywords

Females;Heterosis;Males;Mammary Growth;Mammary Tumorigenesis