ISSN:
1573-7276
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract PNKT-4B is an aneuploid cell line derived from a herpesvirus-induced renal adenocarcinoma of Rana pipiens that displays restricted invasion at 21°C or cooler and invasion at 23°C through 28°C. Metaphase chromosomes obtained from subcultures (passages 297; 345–347) grown at 18°C or 28°C were Giemsa stained or N-banded with acidic silver nitrate. Cells grown at 18°C displayed a modal chromosome number of 41, while 28°C cultures displayed a modal number of 40. The distribution of the chromosomes suggests that the two temperatures may be allowing growth of different subclonal populations. N-banding of chromosomes at both temperatures revealed an increase of active nucleolar organizer regions (NORs) over normal frog tissues, 2/2N. Analysis of 200 N-banded spreads from cells grown at each temperature revealed modal numbers of 9 NORs/cell and modal numbers of 6 NOR-containing chromosomes/cell. Nine specific NOR-containing chromosomes were identified and scored. Similar distributions were observed at 18°C and 28°C. The data imply that the modal number of PNKT-4B has shifted since it was first described, 39, and differs at invasion-permissive and — restrictive temperatures. Increased numbers of active NORs and alterations of NOR-containing chromosomes imply an amplification of rDNA over the amount in normal frog.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00141257
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