RESUMO
The karyotype of moose (2n = 68) is characterized by very large C-bands close to the centromeres of most chromosomes. The C-banded material represents 40% of the genome. For further characterization of the heterochromatin chromosome spreads were treated with restriction endonucleases and the restriction enzyme (Re) banding pattern was analyzed. HaeIII, AluI, MboI, RsaI and HinfI produced informative Re-bands. DdeI induced an even digestion with no banding. Staining with chromomycin A3 produced bright fluorescence in regions corresponding to C-bands. Labeling with BrdUrd during late S phase differentiates four regions in the C banded area. The sequence of these regions from centromere to telomere are: late, early, late and early replicating. The authors propose the existence of five satellite DNA families with distinctive characteristics of G-C and A-Trichness and different replication timing, and point out the different clusters for the endonucleases detailed above and their varying location in the chromosomes examined.
Assuntos
Cervos/genética , Heterocromatina/análise , Animais , Bandeamento Cromossômico , Enzimas de Restrição do DNA , DNA Satélite , Feminino , Cariotipagem , Masculino , Família MultigênicaRESUMO
The karyotype 47,XX,+9p was observed in a 50-year-old mentally retarded woman with dysmorphic facies, severe cerebral malformations, limb deformities, retarded sexual maturation and deviating dermatoglyphs. Banding analysis showed the extra chromosome to be composed of 9p and the proximal part of 9q comprising a large secondary constriction. The breakage point is estimated as 9q13. Hemozygous large C bands were observed in both chromosomes No. 9 as well as in the extra chromosome. Clinically this case can be regarded as a pure 9p trisomy. The mechanism causing the syndrome is thought to be malsegregation of a deleted chromosome No. 9.
Assuntos
Cromossomos Humanos 6-12 e X , Trissomia , Anormalidades Múltiplas/genética , Adulto , Encéfalo/anormalidades , Humanos , Deficiência Intelectual/genética , MasculinoRESUMO
Amitrole (3-amino-1,2,4-triazole) inhibits bacterial growth both in Escherichia coli and Salmonella typhimurium at a concentration of 0.5% in minimal medium. Repression of growth already occurs at a concentration of 0.1% of amitrole in this medium. In complete medium the bacteria tolerate concentrations of amitrole as high as 1.7-2.4% before growth ceases. Mutagenicity was tested by differential growth comparisons on E. coli strains W 3110 thy pol A1, defective in DNA polymerase I, and its revertant pol A+. Known mutagens (MMS, NTG, mitomycin C) were used as positive controls. Analogous negative results were also obtained in a revertant test when several trp mutant strains of Salmonella were used.
Assuntos
Amitrol (Herbicida)/farmacologia , Escherichia coli/efeitos dos fármacos , Mutagênicos , Salmonella typhimurium/efeitos dos fármacos , Triazóis/farmacologia , DNA Nucleotidiltransferases/metabolismo , Reparo do DNA/efeitos dos fármacos , DNA Bacteriano , Escherichia coli/enzimologia , Escherichia coli/crescimento & desenvolvimento , Salmonella typhimurium/enzimologia , Salmonella typhimurium/crescimento & desenvolvimentoRESUMO
Amitrole was highly toxic at early larval stages of Drosophila (LD50 is 40 ppm in medium). Toxicity of amitrole was also revealed by prolongation of development time even at 10 ppm. However, no mutagenic effects of amitrole were observed either in the sex chromosome non-disjunction test (females reared on medium containing amitrole at 10 ppm) or in the sex-linked recessive lethal test (males reared on medium containing amitrole at 10 ppm).
Assuntos
Amitrol (Herbicida)/farmacologia , Drosophila melanogaster/efeitos dos fármacos , Mutagênicos , Triazóis/farmacologia , Amitrol (Herbicida)/toxicidade , Animais , Aberrações Cromossômicas , Feminino , Genes Letais , Genes Recessivos , Ligação Genética , Masculino , Cromossomos SexuaisRESUMO
Effects of amitrole (3-amino-1,2,4-triazole) on human leucocytes in culture were investigated. Amitrole interfered with lymphoblast transformation and inhibited cell growth in concentrations of 0.2% w/v and higher. Selected metaphases were examined for the presence of chromosome and chromatid aberrations. No clastogenic effects were observed.
