Deatrick J
Centre de Génétique Moleculaire, C.N.R.S., Gif-sur-Yvette, France.
Dev Genet. 1992;13(5):326-30. doi: 10.1002/dvg.1020130503.
Polyhomeotic is a member of a group of genes, the Pc-group responsible for the maintenance of gene expression during development. In particular, the Pc-group of genes is involved in the correct expression of homeotic genes of the bithorax and Antennapedia complexes. Molecular analysis reveals that the Pc-group genes function relatively late in development, once homeotic gene expression has been correctly initiated. This initiation of homeotic gene expression depends on interaction between genes in the segmentation gene hierarchy, the gap and pair-rule genes. The in situ analysis presented here indicates that polyhomeotic transcripts are expressed in a spatially restricted fashion early in development. This blastoderm expression is under the control of genes in the segmentation hierarchy. Given these results, and the role of polyhomeotic in the correct maintenance of homeotic gene expression, I propose that polyhomeotic expression may relay the initiation of homeotic gene expression with other mechanisms involved in the maintenance of this expression, involving the other Pc-group genes.
多同源异型蛋白是一组基因中的一员，即负责在发育过程中维持基因表达的Pc组基因。具体而言，Pc组基因参与双胸复合体和触角足复合体同源异型基因的正确表达。分子分析表明，Pc组基因在发育过程中发挥作用相对较晚，此时同源异型基因的表达已正确启动。同源异型基因表达的启动依赖于体节基因层级中基因之间的相互作用，即缺口基因和成对规则基因。此处呈现的原位分析表明，多同源异型蛋白转录本在发育早期以空间受限的方式表达。这种胚盘层表达受体节层级中基因的控制。鉴于这些结果以及多同源异型蛋白在同源异型基因表达正确维持中的作用，我提出多同源异型蛋白的表达可能与参与维持这种表达的其他机制（涉及其他Pc组基因）一起传递同源异型基因表达的启动。
