Hoxb‐2 transcriptional activation in rhombomeres 3 and 5 requires an evolutionarily conserved cis‐acting element in addition to the Krox‐20 binding site.

摘要: Segmentation is a key feature of the development vertebrate hindbrain where it involves generation repetitive morphological units termed rhombomeres (r). Hox genes are likely to play an essential role in specification segmental identity and we have been investigating their regulation. We show here that mouse chicken Hoxb-2 dependent for expression r3 r5 on homologous enhancer elements binding this r3/r5-specific transcriptional activator Krox-20. Among three Krox-20 sites enhancer, only high-affinity site absolutely necessary activity. In contrast, identified additional cis-acting element, Box1, r3/r5 It conserved both sequence position respective within enhancers. Furthermore, short 44 bp spanning Box1 can act as when oligomerized. may therefore constitute recognition another factor cooperating with Taken together, these data demonstrate conservation gene regulation function during evolution.