ISSN:
1617-4623
Keywords:
Key words rDNA genes
;
Hybrids
;
Drosophilamelanogaster
;
Drosophila simulans
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract 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 , y w (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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02191828
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