Obtaining of Agr2 Specific Antibodies and Determination of the Agr2 Protein Distribution Pattern during Early Embryonic Development and Tadpole Regeneration in Xenopus laevis

The Agr (anterior gradient) group proteins belong to the family of proteins with a noncanonical thioredoxin motif and are involved in the regulation of various processes: embryonic development, regeneration, and oncogenesis. Normally, the human Agr2 gene is predominantly expressed in the secreting cells of mucin-producing organs. However, Agr2 is associated with active metastasis during the development of some types of malignant tumors. The molecular mechanism of its functioning is poorly understood. The model of Xenopus laevis embryos is one of the most convenient and available basic models for the proper study of various molecular mechanisms and signaling cascades of proteins. Previously, only the expression activity of the Agr genes was studied in this model; in particular, active expression of the Agr2 gene was demonstrated in the early stages of embryonic development and during tadpole regeneration of the tail and hindlimbs in Xenopus laevis. To begin the study on the molecular mechanism of the Agr2 protein functioning, it is necessary to obtain Agr2 specific antibodies and to test their effectiveness, which was the main goal of this work. The obtained purified antibodies were tested by the immunohistochemical method; as a result, the distribution pattern of the Agr2 protein during early development of the embryos and in regenerating tails of the tadpoles of Xenopus laevis, completely coinciding with the expression pattern of this gene, was first obtained.