Caracterização citoquimica de complexos DNA-proteina contendo variantes de histona H1

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

The critical electrolyte concentrations (CEC) of spenn chromatin iTom animal species known or suspected to contain histone H1 variants were compared by examining the affinity of their DNA-protein complexes for toluidine blue in the presence of Mg2+. BulliTog, sea urchin, honeybees, stingless bees and bumblebee spennatozoa and chicken erythrocytes were studied. The CEC for Rana catesbeiana and two sea urchin species were similar to that of histone H5-containing chromatin iTom chicken erythrocytes, thus confinning the biochemical and structural similarities of these DNA-protein complexes. The CEC for bees and the bumblebee, Bombus atratus, showed no particular phylogenetic relationship. We conc1uded that the CEC ofhistone Hl-containing spenn cell chromatin is a useful indicator ofvariability _in DNA-protein complexes but is oflittle phylogenetic value. Suspicion that a lysine-rich somatic-like histone (H1) occurs in chromatin spennatozoa of the honey bee were confinned by 5% PCA extraction and electrophoresis in 15% polyacrylamide gels containing 6.25M urea. Five bands with slower migration as compared with the standards were detected. Our data suggest that a lysine-rich histone (H1), spenn specific with lower basic charge density or large molecular mass occurs in the spenn cells of the honey bee

ASSUNTO(S)

citoquimica cromatina

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