The effects of collagen synthesis inhibitory drugs on somitogenesis and myogenin expression in cultured chick and mouse embryos.
The role of fibrillar collagen on myogenic differentiation has previously been studied in tissue culture cell lines but has not been studied in situ. We treated cultured chick and mouse embryos with collagen synthesis inhibitors to determine the role of fibrillar collagen on somitogenesis and on myogenic differentiation in vivo. Stage 12 chick embryos and 8.7 dpc mouse embryos were cultured in control medium or a range of concentrations of the collagen synthesis inhibitors ethyl-3,4-dihydroxybenzoate (EDHB) or cis-hydroxy-proline (CHP). Chick embryos were cultured for 24 h and mouse embryos were cultured for 30 h. Both collagen synthesis inhibitors produced a range of somite abnormalities including formation of fewer and irregular somites in both chick and mouse at high drug concentrations, as well as formation of double somites in EDHB-treated chick embryos. Examination of EDHB-treated mouse embryos by scanning electron microscopy demonstrated a dosage-dependent loss of fibrillar collagen and associated extracellular matrix. Expression of myogenin in EDHB-treated mouse embryos, examined by whole-mount in situ hybridization, was suppressed at higher dosage levels. This study suggests that inhibition of fibrillar collagen production and/or loss of fibrillar collagen in the developing avian and mammalian embryo results in abnormal somite formation and perturbed myogenic differentiation.
Chernoff
E A
EA
Department of Biology, Indiana University-Purdue University Indianapolis, Indiana 46202-5132, USA. echernof@iupui.edu
Clarke
D O
DO
Wallace-Evers
J L
JL
Hungate-Muegge
L P
LP
Smith
R C
RC
D000818:Animals; D002642:Chick Embryo; D003094:Collagen / Q000096:biosynthesis / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000187:drug effects*; D005260:Female; D062385:Hydroxybenzoates / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006909:Hydroxyproline / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D017403:In Situ Hybridization; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008855:Microscopy, Electron, Scanning; D018008:Myogenin / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D015347:RNA Probes; D019170:Somites / Q000187:drug effects* / Q000648:ultrastructure*; D014158:Transcription, Genetic
D062385:Hydroxybenzoates; C503801:Myog protein, mouse; D018008:Myogenin; D015347:RNA Probes; C018063:ethyl protocatechuate; D003094:Collagen; D006909:Hydroxyproline