RESUMO
Analysis of 28 strains of Drosophila buzzatii from six different localities revealed that populations from southern Brazil apparently differ from northeastern populations in chromosome structure. Of the 16 polymorphic chromosome inversions detected in this species, only two (2j and 5c2) were present in southern populations. The Northeastern populations were the first of this species found not to have the 2j inversion. This suggests that the populations of Drosophila buzzatii may have lost chromosome polymorphism during dispersion, supporting the idea that the current geographic distribution of this species in South America is due to active dispersion.
Assuntos
Aberrações Cromossômicas , Drosophila/genética , Variação Genética , Animais , Brasil , Inversão Cromossômica , Feminino , Masculino , Polimorfismo Genético , Especificidade da EspécieRESUMO
A simple technique for placing reference markers on serial sections is presented. The objective is to permit proper cut orientation, especially when the shape of a structure appearing in the various cuts is to be digitized for computer analysis.