| Abstract |
A continuation of the history of the swine kidney cell line, IB-RS-2, as
well as the evolution of its chromosome complement, from the 56th to the
154th cell transfers are given. Up to the 75th transfer, there was a
prevalence of cells with 37 centromeres belonging to 1.1 type (Table I).
After the recovery of the cultures from a dramatic cell necrosis, the
prevalent karyotypes had 38 centromeres. These karyotypes could be found
in the cell clones derived from the parental cell population. It would
appear that the seven clones which could be analysed are descendants of
cells with 38 chromosomes, type 2.2: two of them, C-12 and C-19 are type 2.2,
but C-19 presents a secondary constriction in one of the largest GIV-XX
chromosomes not found in C-12; five of them have a new large
subacrocentric chromosome (SA). C-16, C-17, C-18 and C-60 (karyotype 2.2.1)
have also a microchromosome which is not found in C-13 (karyotype 2.2.2)
It seems that these five clones had been originated from a cell of 2.2
karyotype, through a recombination between one of the largest GIV-XX and
one of the GVI chromosomes, giving rise to the large SA and to the
microchromosome. Afterwards, in C-13, this microchromosome was lost.
|
|---|
