A hedgehog-like signal is involved in slow muscle differentation in Sepia officinalis

• Main Authors: A Grimaldi, G Tettamanti, ML Guidali, MF Brivio, R Valvassori, M de Eguilor
• Format: Publication
• Language: English
• Published: ISJ 2007
• Subjects: development; helical and cross-striated fibres; Hh-like protein; mollusc; muscle differentiation

In the tentacle of Sepia officinalis, smooth-like, helical and cross-striated fibres deriving from different populations of myoblasts are present. Myoblasts appear at different times during the development and express two muscle-specific transcription factors: Myf5-like and MyoD-like factors. Myoblasts expressing Myf5 give rise to slow fibres, whereas fast fibres derive from MyoD+ myoblasts. We found that a Hedgehog (Hh)-like signal was present in the central nerve cord of the tentacle from the early stages of development and in a specific population of myoblasts which are the precursors of slow muscle fibres. The model showed interesting similarities with vertebrates, in which Sonic hedgehog is a protein secreted by axial structures (the notochord and neurotube) and is involved in slow muscle differentiation and in survival of muscle precursors.