ABSTRACT: In an attempt to characterize biologic properties of green turtle fibropapillomatosis (GTFP), blood cells, dermis of normal skin, dermis of cutaneous fibropapillomas, and visceral fibroblastic nodules of green turtles Chelonia mydas with cutaneous fibropapilloma were examined by flow cytometry. DNA of each sample was stained with propidium iodide and histograms were recorded utilizing a FACSCAN flow cytometer. All samples examined had similar histograms, indicative of normal cell cycles and diploid profiles. Small S phase and G₂M fractions (<5%) indicated a low mitotic activity and a nonproliferating state. Statistical analyses were performed on the coefficient of variation (CV) of the G₁ peak for the various tissues analyzed. The mean CV for blood from all the unaffected turtles was 3.21 while that from turtles afflicted with GTFP was 3.43. CVs of normal skin from healthy turtles and turtles afflicted with GTFP were 4.25 and 4.41 respectively. The mean CV for fibropapillomas was 5.27, a number which, though higher than either blood or normal skin, probably reflects the difference in stain uptake characteristics between fibropapillomas and the other 2 tissues rather than any inherent DNA or ploidy difference.

KEY WORDS: Fibropapilloma . Flow cytometry . Green turtle . Chelonia mydas

Published in DAO Vol. 22, No. 1 (1995) on May 4
ISSN: 0177-5103. Copyright © Inter-Research, Oldendorf/Luhe, 1995