Thymosin beta10 mRNA expression during early postimplantation mouse development.

The beta-thymosins are a family of monomeric actin sequestering peptides that regulate actin dynamics within the cells. During embryogenesis the control of actin polymerization is essential in processes such as cell migration, angiogenesis and neurogenesis. Here we report that the levels of thymosin beta10 (Tbeta10) mRNA strongly increase during early postimplantation mouse embryogenesis as well as during in vitro P19 cell differentiation, indicating that this peptide plays an important role in early development. Moreover, analysis of the spatial distribution of Tbeta10 mRNA in 9.5-12.5 days postcoitum mouse embryos showed a remarkable presence of this transcript in mesenchymal structures as well as in the mantle layer of spinal cord. Interestingly, we observed differences in the distribution of the mRNAs encoding Tbeta10 and Tbeta4, another member of the beta-thymosin family, suggesting different roles for these peptides during mouse embryogenesis.