Association of Surfactant Protein with Expression of and in Rabbit Fetal Lung.

genes regulate organ formation and identity of the embryo, and expressed in specific temporo-spatial patterns in the developing embryo. We compared the expression levels of the , , surfactant protein , and genes in immature and mature rabbit fetal lung tissues, and to uncover roles for Hoxa5, Hoxb5, SP-A, and SP-B. Cesarean sections were performed after rabbits were divided into two groups of 30-31 days of gestation (term group, n = 24) and 26-27 days of gestation (preterm group, n = 24). mRNA levels of , , , and were compared by quantitative reverse transcriptase polymerase chain reaction, and protein expression of Hoxa5 and Hoxb5 was compared by western blot analysis. Fetal lung tissue histology was observed by hematoxylin and eosin (H&E) staining. The relative expression ratios of and mRNA in the term to preterm groups were 2.45:1 and 2.94:1, respectively. mRNA and protein levels decreased in the term group, with a relative expression ratio of 0.48:1 and 0.50:1, however, mRNA and protein levels increased in the term group with a relative expression ration of 2.99:1 and 2.33:1, respectively, for the term to preterm groups. Moreover, a significant positive correlation was found between the expression of and , in the term group. gene may be essential for the expression of and in term rabbits. The gene may be an important factor for lung maturation in preterm rabbits.