AnÃlise cariotÃpica em representantes do GÃnero Dichotomius (Coleoptera, Scarabaeidae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Dichotomius is a pertaining sort strict to the New World and that it presents 153 described species approximately. For Brazil it more than has register of occurrence of 83 species. The meiotic and mitotic chromosomes of Dichotomius sericeus, Dichotomius nisus and Dichotomius semisquamosus, had been studied through the conventional staining, C-banding and staining with silver nitrate (AgNO3). In D. nisus and D. semisquamosus was used fluorescent hibridization in situ (FISH) with probe of DNAr 28S. The three analyzed species had presented asymmetric karyotype with 2n=18, chromosomes meta-submetacentric and gradual reduction of size, except pair 1 that it presented great size in relation to the other chromosomes of the complement. D. nisus and D. semisquamosus had presented sex mechanism of the Xyp type, whereas in D. sericeus the identified sex mechanism was Xyr. The analysis of the constitutive heterochromatin (HC) for C-banding revealed to the presence of blocks of HC in the pericentromeric regions of all the chromosomes in the three species. With regard to the size of the blocks, D. semisquamosus, presented comparative lesser blocks when with the blocks visualized in D. sericeus and D. nisus. The staining with silver nitrate (AgNO3) revealed to corresponding marks the RONs in the sex bivalent in D. sericeus and D. nisus and in a autosome pair in D. semisquamosus. Additionally, the AgNO3 staining also marked the regions of HC in the three species. The FISH method confirmed the localization of the ribosomal sites, in the sex bivalent of D. nisus and in the autosome bivalent of D. semisquamosus, coinciding with the markings gotten for the AgNO3 staining

ASSUNTO(S)

estudo cromossÃmico ciencias biologicas heterocromatina citogenÃtica animal coleoptera cariÃtipo

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