Expression Pattern Of Mid1/mid2 During Mouse Early Development

Opitz syndrome is an inherited multiple-organ disorder primarily affecting midline structures. X-linked OS is caused by mutations in the ubiquitin ligase MIDI, which is located on the short arm of the human X chromosome within Xp22.3. MID2 is a homologue of MID1, and it maps to Xq22 in human. The two x-linked genes share the same domains, the same exon-intron organization, a high degree of similarity at the protein level and the same subcellular localization. Together, these data suggest that MID2 is a causative gene of OS. We analyze the expression pattern of Mid1/Mid2 by Real-time PCR. We show that the expression of Mid2 overlaps with that of Mid1 in mouse embryo. At E9.5/10.5, Mid1 expression level is high and Mid2 expression level is low. At E11.5, the highest level of Mid2 expression is detected, unlike Mid1 for which expression was low. At E12.5/13.5, Mid1 expression level is higher than Mid2 again. These data suggest that MID1 and MID2 have a similar biochemical function but a different physiological role during development. We also analyze the expression of Mid2 in mouse craniofacial region. We show that Mid2 is expressed in the ectoderm of the midfacial processes. The pattern of expression in the midfacial region implicates the important role of MID2 in craniofacial development.