The segregation pattern of chromosomes 14 and 18 were analysed in recombinant inbred strains of mice developed from KE and CBA/Kw strains. The analysis was possible owing to the fact that the C-band on chromosomes 14 of the CBA/Kw strain and that of chromosome 18 of the KE strain show size polymorphism: while the CBA/Kw mice have a small sized C-band on chromosome 14, the KE mice show small C-bands on chromosome 18. Chromosomes were identified by G-banding and FISH. The results show that the chromosomes with small centromeric chromatin segregate preferentially.
M. Lenartowicz, Department of Genetics and Evolution, Institute of Zoology, Jagiellonian University, R. Ingardena 6, 30-060 Krakow, Poland, E-mail: Lena@zuk.iz.uj.edu.pl