Hox11-family genes XHox11 and XHox11L2 in xenopus: XHox11L2 expression is restricted to a subset of the primary sensory neurons

The mouse genome contains a small family of homeobox genes related to Hox11, but relatively little is known about the expression of these genes during early development. Hox11 itself is expressed in the embryonic spleen, among other tissues, and is required for its formation. No description of Hox11L2 expression has been presented previously. We have isolated the Xenopus orthologs of Hox11 and Hox11L2 and have carefully compared their expression patterns during embryogenesis. The localization of Xhox11 transcripts in the branchial arches, cranial sensory ganglia and spinal cord is similar, but not identical, to that of mouse Hox11. Xhox11 expression is not detected in the developing spleen. XHox11L2 is expressed exclusively in a portion of the primary sensory system in the frog embryo, including the cranial sensory ganglia and the Rohon-Beard sensory neurons. There is significant overlap in the patterns of Xhox11 and XHox11L2 expression in the spinal cord and cranial sensory ganglia during early development, suggesting that they may function redundantly in these tissues. The timing of Xhox11 and Xhox11L2 expression indicates that Hox11-family members may participate in the final stages of the differentiation process.