title: Characterization of a male-predominant antisense transcript underexpressed in hybrids of Drosophila pseudoobscura and D. persimilis.
abstract: Characterizing genes that are misregulated in hybrids may elucidate the genetic basis of hybrid sterility or other hybrid dysfunctions that contribute to speciation. Previously, a small segment of a male-predominant transcript that is underexpressed in adult male hybrids of Drosophila pseudoobscura and D. persimilis relative to pure species was identified in a differential display screen. Here, we obtained the full sequence of this 1330-bp transcript and determined that it is an antisense message with high sequence similarity to the D. melanogaster TRAP100 gene, part of the Mediator protein complex that regulates transcriptional initiation during development. Both the sense and the antisense messages are transcribed in D. pseudoobscura, but only the sense message (TRAP100) is transcribed in D. melanogaster complex species. Unlike the antisense message, the sense message is transcribed similarly in D. pseudoobscura males and females and in hybrids of D. pseudoobscura and D. persimilis. The high sequence similarity between distantly related species suggests that the sense message is functionally constrained within the genus. We speculate that the antisense transcript may have evolved a role in male-specific post-transcriptional regulation of TRAP100 in the D. pseudoobscura lineage and that its underexpression in sterile hybrid males may cause an overproduction of TRAP100 protein, possibly yielding deleterious effects.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA. mnoor@lsu.edu
authors.forename: Mohamed A F
authors.initials: MA
authors.lastname: Noor
authors.forename: Pawel
authors.initials: P
authors.lastname: Michalak
authors.forename: David
authors.initials: D
authors.lastname: Donze
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D019070:Cell Lineage; D002678:Chimera / Q000235:genetics*; D003433:Crosses, Genetic; D004330:Drosophila / Q000145:classification / Q000235:genetics*; D029721:Drosophila Proteins; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D016372:RNA, Antisense / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D029721:Drosophila Proteins; C503844:MED24 protein, Drosophila; D016372:RNA, Antisense; D014157:Transcription Factors