Abstract
DNA methyltransferase 1 (DNMT1), the first-identified DNA methyltransferase in mammals, has been well studied in the control of embryo development and somatic homeostasis in mice and humans. Accumulating reports have demonstrated that DNMT1 plays an important role in the regulation of differentiation and the activation of immune cells. However, little is known about the effects of porcine DNMT1 on such functional regulation, especially the regulation of the biological functions of immune cells. In this study, we report the cloning of DNMT1 (4833 bp in length) from porcine alveolar macrophages (PAMs). According to the sequence of the cloned DNMT1 gene, the deduced protein sequence contains a total of 1611 amino acids with a 2 amino acid insertion, a 1 amino acid deletion, and 12 single amino acid mutations in comparison to the reported DNMT1 protein. A polyclonal antibody based on a synthetic peptide was generated to study the expression of the porcine DNMT1. The polyclonal antibody only recognized the cloned porcine DNMT1 and not the previously reported protein due to a single amino acid difference in the antigenic peptide region. However, the polyclonal antibody recognized the endogenous DNMT1 in several porcine cells (PAM, PK15, ST, and PIEC) and the cells of other species (HEK-293T, Marc-145, MDBK, and MDCK cells). Moreover, our results demonstrated that all the detected tissues of piglet express DNMT1, which is the same as that in porcine alveolar macrophages. In summary, we have identified a porcine DNMT1 variant with sequence and expression analyses.