Altered neuronal lineages in the facial ganglia of Hoxa2 mutant mice

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• 作者：Xiu Yang ; Yuefang Zhou ; Erin A. Barcarse ; Stephen O’ ; Gorman
• 关键词：Hoxa2 ; Cranial ganglia ; Lineage marking ; Neural crest ; Neurogenesis ; Hox genes ; P19 cells ; Pbx ; Meis
• 刊名：Developmental Biology
• 出版年：2008
• 出版时间：1 February 2008
• 年：2008
• 卷：314
• 期：1
• 页码：171-188
• 全文大小：5658 K

文摘

Neurons of cranial sensory ganglia are derived from the neural crest and ectodermal placodes, but the mechanisms that control the relative contributions of each are not understood. Crest cells of the second branchial arch generate few facial ganglion neurons and no vestibuloacoustic ganglion neurons, but crest cells in other branchial arches generate many sensory neurons. Here we report that the facial ganglia of Hoxa2 mutant mice contain a large population of crest-derived neurons, suggesting that Hoxa2 normally represses the neurogenic potential of second arch crest cells. This may represent an anterior transformation of second arch neural crest cells toward a fate resembling that of first arch neural crest cells, which normally do not express Hoxa2 or any other Hox gene. We additionally found that overexpressing Hoxa2 in cultures of P19 embryonal carcinoma cells reduced the frequency of spontaneous neuronal differentiation, but only in the presence of cotransfected Pbx and Meis Hox cofactors. Finally, expression of Hoxa2 and the cofactors in chick neural crest cells populating the trigeminal ganglion also reduced the frequency of neurogenesis in the intact embryo. These data suggest an unanticipated role for Hox genes in controlling the neurogenic potential of at least some cranial neural crest cells.