Abstract

Maize seedlings of the genotype C I Sh Wx were fumigated with hydrogen fluoride gas (HF) continuously for 4, 6, 8 and 10 days. Miscrospore mitosis of the treated plants indicated the presence of fragments and bridges suggesting the occurrence of the phenomenon of breakage-fusion-bridge cycle of McClintock. This phenomenon was later confirmed by the production of endosperm mosaicisms. The period of fumigation was clearly related to the extent of the area resulting from the B-F-B cycle. Recombination values were estimated from F2 data for the regions C-sh and sh-wx. There was a significant increase in the frequency of crossing over for region I with maximum increase being for the 4 days duration. The recombination value for region II showed no significant deviation from the control. These findings indicate that HF in addition to being a mutagenic agent is also able to reduce crossing over in certain chromosome segments.

• Related Studies :

  • Induction of chromosomal aberrations in male mouse germ cells by uranyl fluoride containing enriched uranium

    Cytogenetic damage induced by a wide range of concentrations of uranyl fluoride injected into mouse testes was evaluated by determining the frequencies of chromosomal aberrations in spermatogonia and primary spermatocytes. Breaks, gaps and polyploids were observed in spermatogonia. The frequencies of the significant type of aberration, breaks, were induced according

  • Chromosome aberrations in cultured rat bone marrow cells treated with inorganic fluorides

    The genotoxic effects of inorganic fluorides were investigated by treating cultured rat bone marrow cells with varying concentrations (0.1-100 microM) of potassium fluoride (KF) and sodium fluoride (NaF) for different durations (12, 24 and 36 h) and measuring the incidence of cells with aberrations and number of breaks per cell.

  • Transforming activities of sodium fluoride in cultured Syrian hamster embryo and BALB/3T3 cells

    The transforming activity of sodium fluoride was studied in the SHE and the BALB/3T3 cell culture systems. Initiating and promoting activities were then investigated by means of the orthogonal methodology. Sodium fluoride was found to induce morphological transformation of SHE cells seeded on a feeder layer of X-irradiated cells at

  • The effect of fluorine and lead ions on the chromosomes of human leucocytes in vitro

    Human leukocytes in the cultures in vitro were exposed to the action of Pb and F ions at the concentrations of 10-3 M and 10-5 M for Pb and 3.15 x 10-3 M, 3.15 x 10-4 M, 3.15 x 10-5 M for F. Both factors caused structural and quantitative aberrations

  • Cytotoxicity and genotoxicity testing of sodium fluoride on Chinese hamster V79 cells and human EUE cells

    The cytotoxic effects of sodium fluoride (NaF) on hamster V79 cells and human EUE cells were studied by measuring the cloning efficiency and DNA, RNA and protein synthesis in cells cultured in the presence of NaF. Potential mutagenicity of NaF was followed on the basis of induced 6-thioguanine-resistant mutants in

• Related FAN Content :

  • Fluoride's Mutagenicity: In vivo Studies

    Consistent with dozens of in vitro studies, a number of in vivo studies, in both humans and animals, have found evidence of fluoride-induced genetic damage. In particular, research on humans exposed to high levels of fluoride have found increased levels of "sister chromatid exchange" (SCE). As noted in one study: "In

  • Fluoride & Liver Cancers in NTP Bioassay

    On October 28, 1988, Battelle Columbus Laboratories submitted its Final Report to the NTP concerning the results of the Mouse study. The principal finding of Battelle's report was that a dose-dependent increase of a rare liver cancer (hepatocholangiocarcinoma) had occurred in the fluoride-treated male and female mice.

  • Fluoride's Mutagenicity: The "Oral Health Research Institute's" Studies

    Although many in vitro and in vivo studies have detected mutagenic effects from fluoride exposure, the Oral Health Research Institute at Indiana University's School of Dentistry has repeatedly failed to find any such effect in multiple studies on the subject.

  • Fluoride/Osteosarcoma Link Is Biologically Plausible

    The "biological plausiblility" of a fluoride-osteosarcoma link is widely acknowledged in the scientific literature. The biological plausibility centers around three facts: 1) Bone is the principal site of fluoride accumulation, particularly during the growth spurts of childhood; 2) Fluoride is a mutagen when present at sufficient concentrations, and 3) Fluoride can stimulate the proliferation of osteoblasts (bone-forming cells).

  • Micronucleus and Sister Chromatid Exchange Frequency in Endemic Fluorosis

    The rise of sister chromatid exchange (SCE) and micronucleus (MN) in the peripheral blood lymphocytes of the fluorine-intoxicated patients indicates that fluorine is a mutagenic agent which can cause DNA and chromosomal damage.