Expression Data from Fluorescently Sorted Muscle Subsets

Skeletal muscles are formed in a variety of shapes and sizes, and this diversity impacts muscle function and disease susceptibility. To understand how muscle diversity is generated, we performed gene expression profiling of muscle subsets from Drosophila embryos. By comparing the transcriptional profiles of two muscle subsets, we identified a core group of founder cell-enriched genes. We screened mutant embryos for muscle defects and identified Sin3A and 10 other transcription and chromatin regulators as having novel functions in the Drosophila embryonic somatic musculature. Sin3A is required for the morphogenesis of a subset of muscles, and Sin3A mutants display muscle loss and misattachment. Additionally, misexpression of identity gene transcription factors in Sin3A heterozygous embryos leads to direct transformations of one muscle into another, while overexpression of Sin3A results in the reverse transformation. Our data implicate Sin3A as a key buffer controlling muscle responsiveness to transcription factors in the formation of muscle identity, thereby generating tissue diversity.

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Dobi KC, Halfon MS, Baylies MK