Molecular characterization of thyroid peroxidase gene in porcine (sus scrofa)

Thyroid peroxidase (TPO) is the key enzyme involved in thyroid hormone synthesis. Several mutations in the TPO gene may affect the normal growth and development of mammals. In this study, the TPO gene was mapped, its expression level was determined in thyroid grand at the age of 1, 20, 45, 60, 90, 120 and 150 days for Jinhua pig, the alternative splicing form was searched and the single nucleotide polymorphism (SNP, A/G642) of TPO gene was analyzed. The results showed that the porcine TPO was mapped to 3q22-27, the expression level of TPO was relatively stable among the various ages and two novel transcript variants in porcine TPO gene were found: the splicing variant TPO-2 lacked exon 8, while TPO-3 lacked exon 8 and exon 14, 15, 16. Moreover, we found that the SNP of A/G642 in the fourteenth exon of TPO gene was significantly associated with ham weight (P < 0.05). Our results provided important basis on the regulation and metabolism of the thyroid gland in animals.