Indirect evidence of alteration in the expression of the rDNA genes in interspecific hybrids between Drosophila melanogaster and Drosophila simulans

Begoña Granadino, Luiz O.F. Penalva, Lucas Sánchez

Research output: Contribution to journalArticle

9 Scopus citations


Crosses between Drosophila melanogaster females and D. simulans males produce viable hybrid females, while males are lethal. These males are rescued if they carry the D. simulans Lhr gene. This paper reports that females of the wild-type D. melanogaster population Staket do not produce viable hybrid males when crossed with D. simulans Lhr males, a phenomenon which we designate as the Staket phenotype. The agent responsible for this phenomenon was found to be the Staket X chromosome (X(mel), Stk). Analysis of the Staket phenotype showed that it is suppressed by extra copies of D. melanogaster rDNA genes and that the X(mel), Stk chromosome manifests a weak bobbed phenotype in D. melanogaster X(mel), Stk/0 males. The numbers of functional rDNA genes in X(mel), Stk and X(mel), yw (control) chromosomes were found not to differ significantly. Thus a reduction in rDNA gene number cannot account for the weak bobbed X(mel), Stk phenotype let alone the Staket phenotype. The rRNA precursor molecules transcribed from the X(mel), Stk rDNA genes seem to be correctly processed in both intraspecific (melanogaster) and interspecific (melanogaster-simulans) conditions. It is therefore suggested that the X(mel), Stk rDNA genes are inefficiently transcribed in the melanogaster-simulans hybrids.

Original languageEnglish (US)
Pages (from-to)89-96
Number of pages8
JournalMolecular and General Genetics
Issue number1
Publication statusPublished - Jan 30 1996



  • Drosophila melanogaster
  • Drosophila simulans
  • Hybrids
  • rDNA genes

ASJC Scopus subject areas

  • Genetics

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