RESUMO
Lymphocytes with different chromosome numbers (46,XX and 47,XX + 21) in cultures, were obtained from the blood of a mosaic of a Down's syndrome patient. Their distinctive susceptibility to chromosome damage induced by bleomycin radiomimetic was tested and compared with lymphocytes from healthy individuals. The test showed that the presence of an extra chromosome 21 occurred in parallel with the rise of an intrinsic basal rate of chromosome damage in trisomic cells.
Assuntos
Bleomicina/farmacologia , Aberrações Cromossômicas/genética , Cromossomos Humanos Par 21/fisiologia , Cromossomos Humanos/genética , Dano ao DNA , Síndrome de Down/genética , Antimetabólitos Antineoplásicos/farmacologia , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/fisiologia , Transtornos Cromossômicos , Dano ao DNA/genética , Diploide , Feminino , Humanos , Recém-Nascido , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Linfócitos/fisiologia , Mosaicismo , TrissomiaRESUMO
A high frequency of satellite association phenomena in a number of specimens of Rattus rattus and R. norvegicus, captured on the coastal fringe of Málaga province (Southern Spain), was found. Only Ag-NOR bearing chromosomes participated in associations in both species. R. rattus is characterized by 14/18 heterologous and R. norvegicus by 5/5 and 13/13 homologous association types.