[The effect of mycoplasmal contamination of cultures of skin fibroblasts from the Indian muntjac and of the subsequent decontamination of the cultures using ciprofloxacin on the karyotypic structure of the cell line].

The karyotypic variability of Indian muntjac skin fibroblast cell line, cultured for 95-168 days after contamination with Acholeplasma laidlawii strain PG-8, has been investigated. The contaminated cultures differ from noncontaminated ones in cell distribution for chromosome number. The noncontaminated cultures have modal number of chromosomes equal to 7 with the main structure variant of the karyotype (SVK) 2+2+1+1+1. In the contaminated cultures the cell number with 7 chromosomes and the main SVK 2+2+1+1+1 decreased, whereas the cell number with 6 chromosomes increased along with the main SVK 2+2+1+1 resulting from the loss of chromosome Y1. The treatment of cells with ciprofloxacin for mycoplasma decontamination did not restore the normal cell distribution for chromosome number. The frequency of chromosomal aberrations, mainly dicentrics, due to telomeric associations, increased after 95-168 days of cultivation of contaminated cells. Chromosomes 1 and 2 and their combination are mainly involved in dicentric formations. The treatment of contaminated cells with ciprofloxacin restores the initial frequency of chromosomal aberrations. Chromosomes with altered structures have not been demonstrated. It has been shown that cells became mycoplasma-free after 15 days of treatment with ciprofloxacin. The role of aneuploidy and dicentrics in cell adaptation to culture conditions is discussed.