Alternative splicing in Drosophila neuronal development.

Post-transcriptional pre-mRNA splicing has emerged as a critical step in the gene expression cascade greatly influencing diversification and spatiotemporal control of the proteome in many developmental processes. The percentage of genes targeted by alternative splicing (AS) is shown to be over 95% in humans and 60% in Drosophila. Therefore, it is evident that deregulation of this process underlies many genetic diseases. Among all tissues, the brain shows the highest transcriptome diversity, which is not surprising in view of the complex inter- and intracellular networks underlying the development of this organ. Reports of isoforms known to function at different steps during Drosophila nervous system development are rapidly increasing as well as knowledge on their regulation and function, highlighting the role of AS during neuronal development in Drosophila.

Sex-Specific Transcript Diversity in the Fly Head Is Established during Pupal Stages and Adulthood and Is Largely Independent of the Mating Process and the Germline.

Alternative splicing (AS), the process which generates multiple RNA and protein isoforms from a single pre-mRNA, greatly contributes to transcript diversity and compensates for the fact that the gene number does not scale with organismal complexity. A number of genomic approaches have established that the extent of AS is much higher than previously expected, raising questions on its spatio-temporal regulation and function. In the present study, we address AS in the context of sex-specific neuronal development in the model Drosophila melanogaster. We report that at least 47 genes display sex-specific AS in the adult fly head. Unlike targets of the classical Sex lethal-dependent sex determination cascade, sex-specific isoforms of the vast majority of these genes are not present during larval development but start accumulating during metamorphosis or later, indicating the existence of novel mechanisms in the induction of sex-specific AS. We also established that sex-specific AS in the adult fly head is largely independent of the germline or the mating process. Finally, we investigated the role of sex-specific AS of the sulfotransferase Tango13 pre-mRNA and provide first evidence that differential expression of certain isoforms of this protein significantly affects courtship and mating behavior in male flies.