title: A hedgehog homolog is involved in muscle formation and organization of Sepia officinalis (mollusca) mantle.
abstract: Our study focuses on the possible involvement of the Hedgehog (Hh) pathway in the differentiation of striated muscle fibres in cuttlefish (Sepia officinalis) mantle. We show here that both an hh-homolog signalling molecule and its receptor Patched (Ptc) are expressed in a specific population of myoblasts which differentiates into the radial fast fibres. To evaluate the functional significance of hh expression in developing cuttlefish, we inhibited the Hedgehog signalling pathway by means of cyclopamine treatment in cuttlefish embryos. In treated embryos, the gross anatomy was considerably compromised, displaying an extremely reduced mantle with a high degree of morphological abnormalities. TUNEL and BrdU assays showed that the absence of an hh signalling induces apoptosis and reduces the proliferation rate of muscle precursors. We therefore hypothesize a possible involvement of Hh and its receptor Ptc in the formation of striated muscle fibres in cuttlefish.
authors.affiliation: Dipartimento di Biologia Strutturale e Funzionale, Università dell'Insubria, Varese, Italy. annalisa.grimaldi@uninsubria.it
authors.forename: Annalisa
authors.initials: A
authors.lastname: Grimaldi
authors.forename: Gianluca
authors.initials: G
authors.lastname: Tettamanti
authors.forename: Francesco
authors.initials: F
authors.lastname: Acquati
authors.forename: Elena
authors.initials: E
authors.lastname: Bossi
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Guidali
authors.forename: Serena
authors.initials: S
authors.lastname: Banfi
authors.forename: Laura
authors.initials: L
authors.lastname: Monti
authors.forename: Roberto
authors.initials: R
authors.lastname: Valvassori
authors.forename: Magda
authors.initials: M
authors.lastname: de Eguileor
mesh_terms: D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D049832:Decapodiformes / Q000196:embryology* / Q000502:physiology; D053823:Hedgehog Proteins / Q000378:metabolism*; D009024:Morphogenesis; D024510:Muscle Development; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000378:metabolism; D032446:Myoblasts / Q000166:cytology* / Q000378:metabolism; D018006:Myogenic Regulatory Factors / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D053823:Hedgehog Proteins; D018006:Myogenic Regulatory Factors