A transcriptomics resource reveals a transcriptional transition during ordered sarcomere morphogenesis in flight muscle

• Published in: eLife Vol. 7
• Main Authors: Spletter, Maria L, Barz, Christiane, Yeroslaviz, Assa, Zhang, Xu, Lemke, Sandra B, Bonnard, Adrien, Brunner, Erich, Cardone, Giovanni, Basler, Konrad, Habermann, Bianca H, Schnorrer, Frank
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publication 30.05.2018; eLife Sciences Publications, Ltd; eLife Sciences Publications Ltd
• Subjects: Bioinformatics; biomechanics; Cell Biology; Computer Science; development; Development Biology; Developmental Biology; Life Sciences; Morphogenesis; muscle; Sarcomere; self organization; Tools and Resources; transcriptomics; stem cells; development; cell biology; developmental biology; muscle; self organization; transcriptomics; biomechanics; D. melanogaster; Sarcomere; Array; Actin filament; Muscles; Heart development
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.34058

Muscles organise pseudo-crystalline arrays of actin, myosin and titin filaments to build force-producing sarcomeres. To study sarcomerogenesis, we have generated a transcriptomics resource of developing flight muscles and identified 40 distinct expression profile clusters. Strikingly, most sarcomeric components group in two clusters, which are strongly induced after all myofibrils have been assembled, indicating a transcriptional transition during myofibrillogenesis. Following myofibril assembly, many short sarcomeres are added to each myofibril. Subsequently, all sarcomeres mature, reaching 1.5 µm diameter and 3.2 µm length and acquiring stretch-sensitivity. The efficient induction of the transcriptional transition during myofibrillogenesis, including the transcriptional boost of sarcomeric components, requires in part the transcriptional regulator Spalt major. As a consequence of Spalt knock-down, sarcomere maturation is defective and fibers fail to gain stretch-sensitivity. Together, this defines an ordered sarcomere morphogenesis process under precise transcriptional control - a concept that may also apply to vertebrate muscle or heart development.