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Titolo:
Formation of a functional morphogen gradient by a passive process in tissue from the early Xenopus embryo
Autore:
McDowell, N; Gurdon, JB; Grainger, DJ;
Indirizzi:
Wellcome, CRC, Inst Canc & Dev Biol, Cambridge CB2 1QR, England Wellcome Cambridge England CB2 1QR Dev Biol, Cambridge CB2 1QR, England Univ Cambridge, Dept Zool, Cambridge, England Univ Cambridge Cambridge England mbridge, Dept Zool, Cambridge, England Addenbrookes Hosp, Dept Med, Cambridge CB2 2QQ, England Addenbrookes HospCambridge England CB2 2QQ , Cambridge CB2 2QQ, England
Titolo Testata:
INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY
fascicolo: 1, volume: 45, anno: 2001,
pagine: 199 - 207
SICI:
0214-6282(2001)45:1<199:FOAFMG>2.0.ZU;2-O
Fonte:
ISI
Lingua:
ENG
Soggetto:
GROWTH-FACTOR-BETA; TGF-BETA; WINGLESS PROTEIN; MESODERM INDUCTION; DROSOPHILA EMBRYO; TOUT-VELU; ACTIVIN; RECEPTOR; GENE; PROTEOGLYCAN;
Keywords:
Xenopus; morphogen; TGF-beta; passive diffusion;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
44
Recensione:
Indirizzi per estratti:
Indirizzo: Gurdon, JB Wellcome, CRC, Inst Canc & Dev Biol, Tennis Court Rd, CambridgeCB2 1QR, England Wellcome Tennis Court Rd Cambridge England CB2 1QR QR, England
Citazione:
N. McDowell et al., "Formation of a functional morphogen gradient by a passive process in tissue from the early Xenopus embryo", INT J DEV B, 45(1), 2001, pp. 199-207

Abstract

In early development much of the cellular diversity and pattern formation of the embryo is believed to be set up by morphogens. However, for many morphogens, including members of the TGF-beta superfamily, the mechanism(s) bywhich they reach distant cells is unknown. We have used immunofluorescenceto detect, at single cell resolution, a morphogen gradient formed across vertebrate tissue. The TGF-P ligand is distributed in a gradient visible up to 7 cell diameters (about 150-200 mum)from its source, and is detectable only in the extracellular space. This morphogen gradient is functional, since we demonstrate activation of a high response gene (Xeomes) and a low-response gene (Xbra) at different distances from the TGF-P source. Expression of the high affinity type II TGF-P receptor is necessary for detection of the gradient, but the shape of the gradient formed only depends in part on the spatial variation in the amount of receptor. Finally, we demonstrate thatthe molecular processes that participate in forming this functional morphogen gradient are temperature independent, since the gradient forms to a similar extent whether the cells are maintained at 4 degreesC or 23 degreesC. In contrast, TGF-beta1 internalisation by cells of the Xenopus embryo is a temperature-dependent process. Our results thus suggest that neither vesicular transcytosis nor other active processes contribute to a significant extent to the formation of the morphogen gradient we observe. We conclude that, in the model system used here, a functional morphogen gradient can be formed within a few hours by a mechanism of passive diffusion.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/11/20 alle ore 22:30:46