XB-ART-51116Dev Dyn January 1, 2016; 245 (1): 47-55.
Identification of genes expressed in the migrating primitive myeloid lineage of Xenopus laevis.
During primitive hematopoiesis in Xenopus, cebpa and spib expressing myeloid cells emerge from the anterior ventral blood island. Primitive myeloid cells migrate throughout the embryo and are critical for immunity, healing, and development. Although definitive hematopoiesis has been studied extensively, molecular mechanisms leading to the migration of primitive myelocytes remain poorly understood. We hypothesized these cells have specific extracellular matrix modifying and cell motility gene expression. In situ hybridization screens of transcripts expressed in Xenopus foregut mesendoderm at stage 23 identified seven genes with restricted expression in primitive myeloid cells: destrin; coronin actin binding protein, 1a; formin-like 1; ADAM metallopeptidase domain 28; cathepsin S; tissue inhibitor of metalloproteinase-1; and protein tyrosine phosphatase nonreceptor 6. A detailed in situ hybridization analysis revealed these genes are initially expressed in the aVBI but become dispersed throughout the embryo as the primitive myeloid cells become migratory, similar to known myeloid markers. Morpholino-mediated loss-of-function and mRNA-mediated gain-of-function studies revealed the identified genes are downstream of Spib.a and Cebpa, key transcriptional regulators of the myeloid lineage. We have identified genes specifically expressed in migratory primitive myeloid progenitors, providing tools to study how different gene networks operate in these primitive myelocytes during development and immunity.
PubMed ID: 26264370
PMC ID: PMC5387764
Article link: Dev Dyn
Species referenced: Xenopus laevis
Genes referenced: adam28.2 cebpa coro1a coro1c ctss dstn fmn1 fmnl1 mmp7 mpo ptpn6 spib timp-1
Morpholinos: spib MO4
Phenotypes: Xla Wt + cebpa (Fig.4.a^1,b^1,c^1,e^1,f^1,g^1,h^1,i^1,i^1)
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References [+] :
Arnold, Inflammatory monocytes recruited after skeletal muscle injury switch into antiinflammatory macrophages to support myogenesis. 2007, Pubmed