The homeotic genes are expressed in epidermis, central nervous system and visceral mesoderm during embryogenesis. Its expression is initiated by the segmentation genes and maintained by the cross-regulation of the homeotic genes, the positive regulati...
The homeotic genes are expressed in epidermis, central nervous system and visceral mesoderm during embryogenesis. Its expression is initiated by the segmentation genes and maintained by the cross-regulation of the homeotic genes, the positive regulation of the trithorax group and the negative regulation of the polycomb group (PcG) genes. The PcG mutation causes the strong ectopic expression of the homeotic genes in the central nervous system so that we investigated the effect of pho, which is one of PcG genes, on the development of the nervous system. We report that the nervous system was very abnormal in the pho maternal effect mutation, but not in the zygotic one. The nervous system of the mutant embryos showed a distorted ladder shape, no expression signal in some segments, or only head development. Based on these findings, unlike other PcG mutations, pho has strong effects on CNS and PNS development.