Msx1 and Msx2 have shared essential functions in neural crest but may be dispensable in epidermis and axis formation in Xenopus.
The homeodomain factors Msx1 and Msx2 are expressed in essentially identical patterns in the epidermis and neural crest of Xenopus embryos during neurula stages. Disruption of Msx1 and Msx2 RNA splicing with antisense morpholino oligonucleotides shows that both factors are also required for expression of the neural crest gene Slug. Loss of Msx1 can be compensated by overexpression of Msx2 and vice versa. Loss of Msx factors also leads to alterations in the expression boundaries for neural and epidermal genes, but does not prevent or reduce expression of epidermal keratin in ventrolateral ectoderm, nor is there a detectable effect on dorsal mesodermal marker gene expression. These results indicate that Msx1 and Msx2 are both essential for neural crest development, but that the two genes have the same function in this tissue. If Msx genes have important functions in epidermis or axial mesoderm induction, these functions must be shared with other regulatory proteins.
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda MD 20892, USA.
Deepak
D
Khadka
Ting
T
Luo
Thomas D
TD
Sargent
D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004817:Epidermis / Q000196:embryology / Q000378:metabolism; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051957:MSX1 Transcription Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009432:Neural Crest / Q000196:embryology / Q000378:metabolism; D020319:Oligodeoxyribonucleotides, Antisense / Q000008:administration & dosage / Q000235:genetics; D012326:RNA Splicing; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D051957:MSX1 Transcription Factor; C084119:MSX2 protein; D020319:Oligodeoxyribonucleotides, Antisense; D029867:Xenopus Proteins