Frizzled-10 promotes sensory neuron development in Xenopus embryos.
Formation of the vertebrate nervous system requires coordinated cell-cell interactions, intracellular signalling events, gene transcription, and morphogenetic cell movements. Wnt signalling has been involved in regulating a wide variety of biological processes such as embryonic patterning, cell proliferation, cell polarity, motility, and the specification of cell fate. Wnt ligands associate with their receptors, members of the frizzled family (Fz). In Xenopus, five members of the frizzled family are expressed in the early nervous system. We have investigated the role of Xenopus frizzled-10 (Fz10) in neural development. We show that Fz10 is expressed in the dorsal neural ectoderm and neural folds in the region where primary sensory neurons develop. Fz10 mediates canonical Wnt signalling and interacts with Wnt1 and Wnt8 but not Wnt3a as shown in synergy assays. We find that Fz10 is required for the late stages of sensory neuron differentiation. Overexpression of Fz10 in Xenopus leads to an increase in the number of sensory neurons. Loss of Fz10 function using morpholinos inhibits the development of sensory neurons in Xenopus at later stages of neurogenesis and this can be rescued by co-injection of modified Fz10B and beta-catenin. In mouse P19 cells induced by retinoic acid to undergo neural differentiation, overexpression of Xenopus Fz10 leads to an increase in the number of neurons generated while siRNA knockdown of endogenous mouse Fz10 inhibits neurogenesis. Thus we propose Fz10 mediates Wnt1 signalling to determine sensory neural differentiation in Xenopus in vivo and in mouse cell culture.
Garcia-Morales
Carla
C
School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
Liu
Chiung-Hui
CH
Abu-Elmagd
Muhammad
M
Hajihosseini
Mohammad K
MK
Wheeler
Grant N
GN
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D051157:Frizzled Receptors / Q000235:genetics / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D051379:Mice; D055495:Neurogenesis / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011984:Sensory Receptor Cells / Q000166:cytology / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000033:anatomy & histology / Q000196:embryology / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
D015415:Biomarkers; D051157:Frizzled Receptors; D016376:Oligonucleotides, Antisense; D034741:RNA, Small Interfering; D051153:Wnt Proteins; D029867:Xenopus Proteins; D051176:beta Catenin; C492384:fzd10b protein, Xenopus