Expression of univin, a TGF-beta growth factor, requires ectoderm-ECM interaction and promotes skeletal growth in the sea urchin embryo.
Pl-nectin is an ECM protein located on the apical surface of ectoderm cells of Paracentrotus lividus sea urchin embryo. Inhibition of ECM-ectoderm cell interaction by the addition of McAb to Pl-nectin to the culture causes a dramatic impairment of skeletogenesis, offering a good model for the study of factor(s) involved in skeleton elongation and patterning. We showed that skeleton deficiency was not due to a reduction in the number of PMCs ingressing the blastocoel, but it was correlated with a reduction in the number of Pl-SM30-expressing PMCs. Here, we provide evidence on the involvement of growth factor(s) in skeleton morphogenesis. Skeleton-defective embryos showed a strong reduction in the levels of expression of Pl-univin, a growth factor of the TGF-beta superfamily, which was correlated with an equivalent strong reduction in the levels of Pl-SM30. In contrast, expression levels of Pl-BMP5-7 remained low and constant in both skeleton-defective and normal embryos. Microinjection of horse serum in the blastocoelic cavity of embryos cultured in the presence of the antibody rescued skeleton development. Finally, we found that misexpression of univin is also sufficient to rescue defects in skeleton elongation and SM30 expression caused by McAb to Pl-nectin, suggesting a key role for univin or closely related factor in sea urchin skeleton morphogenesis.
Zito
Francesca
F
Istituto di Biomedicina e Immunologia Molecolare, Sezione Biologia dello Sviluppo, Consiglio Nazionale delle Ricerche, Palermo, Italy.
Costa
Caterina
C
Sciarrino
Serafina
S
Poma
Veronica
V
Russo
Roberta
R
Angerer
Lynne M
LM
Matranga
Valeria
V
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D004475:Ectoderm / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D008845:Microinjections; D000075983:Nectins; D012333:RNA, Messenger / Q000378:metabolism; D012617:Sea Urchins / Q000033:anatomy & histology / Q000196:embryology*; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D019485:Bone Morphogenetic Proteins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D000075983:Nectins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C090547:univin; C071119:SM30 protein, Strongylocentrotus purpuratus