MouseSeboxhomeobox gene expression in skin, brain, oocytes, and two-cell embryos

Sebox is a mouse paired-like homeobox gene, previously namedOG-9. Sebox genomic DNA and cDNA were cloned and sequenced. In addition, rat and humanSebox genomic DNAs were cloned and sequenced, and the predicted amino acid sequences were compared. The mouseSebox gene was mapped to chromosome 11 near theEvi 2 locus. The mouseSebox gene is expressed in brain, skin, ovary, and liver of mice. In the brain, theSebox gene is expressed in the cerebral cortex and CA areas of the hippocampus, pontine nuclei, choroid plexus, and the cerebellum. Northern analysis and RNase protection assays revealed low levels ofSebox RNA in 12-day mouse embryos and higher levels in 18- and 19-day embryos. In late embryos and newborn mice,Sebox expression is localized in the epidermis. In adult mice,Sebox RNA was found in maturing oocytes and in fertilized eggs; however, the abundance ofSebox RNA is decreased in the two-cell embryo, and little or none was detected in the four-cell embryo. Hence,Sebox is a maternally expressed homeobox gene.