P element insertion is essentially random at the scale of the genome. However, P elements containing regulatory sequences from Drosophila engrailed and polyho- meotic genes and from the Bithorax and Antennapedia com- plexes show some insertional specificity by frequently insert- ing near the parent gene (homing) and/or near genes con- taining Polycomb group response elements (preferential insertion). This phenomenon is thought to be mediated by Polycomb group proteins. In this report, we describe a case of homing of p elements containing regulatory sequences of the linotte gene. This homing occurs with high frequency (up to 20 of the lines) and high precision (inserted into a region of 展开▼
