Simpler mode of inheritance of transcriptional variation in male Drosophila melanogaster.

Sexual selection drives faster evolution in males. The X chromosome is potentially an important target for sexual selection, because hemizygosity in males permits accumulation of alleles, causing tradeoffs in fitness between sexes. Hemizygosity of the X could cause fundamentally different modes of inheritance between the sexes, with more additive variation in males and more nonadditive variation in females.

Sex-specific expression of alternative transcripts in Drosophila.

Background: Many genes produce multiple transcripts due to alternative splicing or utilization of alternative transcription initiation/termination sites. This 'transcriptome expansion' is thought to increase phenotypic complexity by allowing a single locus to produce several functionally distinct proteins. However, sex, genetic and developmental variation in the representation of alternative transcripts has never been examined systematically.

Extensive sex-specific nonadditivity of gene expression in Drosophila melanogaster.

Assessment of the degree to which gene expression is additive and heritable has important implications for understanding the maintenance of variation, adaptation, phenotypic divergence, and the mapping of genotype onto phenotype. We used whole-genome transcript profiling using Agilent long-oligonucleotide microarrays representing 12,017 genes to demonstrate that gene transcription is pervasively nonadditive in Drosophila melanogaster. Comparison of adults of two isogenic lines and their reciprocal F1 hybrids revealed 5820 genes as significantly different between at least two of the four genotypes in either males or females or across both sexes.