The homeodomain-containing gene Xdbx inhibits neuronal differentiation in the developing embryo.
The development of the vertebrate nervous system depends upon striking a balance between differentiating neurons and neural progenitors in the early embryo. Our findings suggest that the homeodomain-containing gene Xdbx regulates this balance by maintaining neural progenitor populations within specific regions of the neuroectoderm. In posterior regions of the Xenopus embryo, Xdbx is expressed in a bilaterally symmetric stripe that lies at the middle of the mediolateral axis of the neural plate. This stripe of Xdbx expression overlaps the expression domain of the proneural basic/helix-loop-helix-containing gene, Xash3, and is juxtaposed to the expression domains of Xenopus Neurogenin related 1 and N-tubulin, markers of early neurogenesis in the embryo. Xdbx overexpression inhibits neuronal differentiation in the embryo and when co-injected with Xash3, Xdbx inhibits the ability of Xash3 to induce ectopic neurogenesis. One role of Xdbx during normal development may therefore be to restrict spatially neuronal differentiation within the neural plate, possibly by altering the neuronal differentiation function of Xash3.
Gershon
A A
AA
Department of Developmental Neurobiology, The Rockefeller University, New York, NY 10021, USA.
Rudnick
J
J
Kalam
L
L
Zimmerman
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D019521:Body Patterning / Q000235:genetics; D002454:Cell Differentiation; D003001:Cloning, Molecular; D005136:Eye Proteins / Q000096:biosynthesis / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017403:In Situ Hybridization; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009432:Neural Crest / Q000196:embryology* / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051880:Receptors, Notch; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D014981:Xenopus / Q000196:embryology* / Q000235:genetics; D029867:Xenopus Proteins
D051792:Basic Helix-Loop-Helix Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D051880:Receptors, Notch; D014157:Transcription Factors; D029867:Xenopus Proteins; C109417:ASCL2 protein, Xenopus; C491212:DBX1 protein, Xenopus; C101907:neurogenin, Xenopus