zfp36 expression delineates both myeloid cells and cells localized to the fusing neural folds in Xenopus tropicalis

International audienceRegulatory RNA binding proteins allow for specific control of gene expression in a very dynamic manner. In mammals ZFP36, formerly known as Tristetraprolin, controls the inflammatory response by binding to an AU-rich element located in the 3' untranslated region of its target mRNAs. The developping embryo relies on a population of primitive macrophages to ensure proper immunity. Although the role of zfp36 in adult immunity has been extensively studied, its expression in the developing immune system has been poorly documented. Here, we have used whole mount in situ hybridization with a 3' UTR specific probe to address the expression of zfp36 in developing Xenopus tropicalis embryos. We have shown that zfp36 is expressed in two distinct cellular populations. First, it is a new marker of primititive myeloid cells, being coexpressed with the myeloid marker mpo. Therefore this early expression may suggest a role for zfp36 in macrophage differentiation and activation. In addition, a second cell population was found to transiently express zfp36, but not mpo, along the fusing neural folds and may correspond to cells undergoing autophagy during neural tube closur