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

Maria Spletter (1) , Christiane Barz (1) , Assa Yeroslaviz (1) , Xu Zhang (1) , Sandra Lemke (1) , Adrien Bonnard (2) , Erich Brunner (3) , Giovanni Cardone (1) , Konrad Basler (3) , Bianca Habermann (2, 1) , Frank Schnorrer (2, 1)

1 MPIB - Max-Planck-Institut für Biochemie = Max Planck Institute of Biochemistry
2 IBDM - Institut de Biologie du Développement de Marseille
3 UZH - Universität Zürich [Zürich] = University of Zurich

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 Drosophila 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 mm diameter and 3.2 mm 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.

Mots clés: Array; Actin filament; Muscles; Heart development

Domaines: Morphogenèse; Bio-informatique [q-bio.QM]

Maria Spletter, Christiane Barz, Assa Yeroslaviz, Xu Zhang, Sandra Lemke, et al.. A transcriptomics resource reveals a transcriptional transition during ordered sarcomere morphogenesis in flight muscle. eLife, 2018, 7, ⟨10.7554/eLife.34058⟩. ⟨hal-01874574⟩