Expression and antibody preparation of POU transcription factor qBrn-1

The transcription factor Brn-1, which belongs to POU-domain family, has been shown to play critical roles in the development of the nervous system. A cDNA clone coding for a quail Brn-1 homologue, qBrn-1, was isolated. To investigate whether this gene plays a role in the development of the quail nervous system, an anti-N-terminal peptide antibody was prepared. The coding region for amino acids 1-79 (the N-terminal domain of qBrn-1) was subcloned into Trx fusion expression vector pET32c and introduced into the Escherichia coli Origami(DE3) cells for efficient expression. After purification, Trx-fused polypeptides, called Trx-qBrn-1N, were used to immunize the rabbits to prepare polyclonal antibodies against qBrn-1. The produced and purified antiserum showed specificity not only to the in vitro expressed qBrn-1, but also to the natural qBrn-1 in tissues. Immunolabeling on sections by the anti-qBrn-1 serum showed that qBrn-1 was specifically expressed in the developing spinal cord and kidney. This suggests that qBrn-1 may play some roles in the development of avian nervous system and kidney, and the preparation of anti-qBrn-1 polyclonal antibody will facilitate further detection of, and functional study on, qBrn-1 both in vivo and in vitro.