Stopped at the border: boundaries and insulators.
Boundaries in chromatin are often marked by the presence of insulator elements. New results in Drosophila have identified an insulator with a proven boundary function essential for development. Other studies suggest a connection between the activity of some insulators and Drosophila trithorax-Group and Polycomb-Group genes. Several examples of vertebrate insulators have now been found; their locations suggest important boundary functions. Enhancer-blocking studies in oocytes and position-effect studies in transformed cells shed new light on insulator mechanisms.
D000818:Animals; D002843:Chromatin / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins; D019476:Insect Proteins / Q000235:genetics; D008957:Models, Genetic; D063150:Polycomb Repressive Complex 1; D014157:Transcription Factors