Boundary bypass activity in the abdominal-B region of the Drosophila bithorax complex is position dependent and regulated
2023
Olga Kyrchanova | Airat Ibragimov | Nikolay Postika | Pavel Georgiev | Paul Schedl
Expression of Abdominal-B (Abd-B) in abdominal segments A5–A8 is controlled by four regulatory domains, iab-5–iab-8. Each domain has an initiator element (which sets the activity state), elements that maintain this state and tissue-specific enhancers. To ensure their functional autonomy, each domain is bracketed by boundary elements (Mcp, Fab-7, Fab-7 and Fab-8). In addition to blocking crosstalk between adjacent regulatory domains, the Fab boundaries must also have bypass activity so the relevant regulatory domains can ‘jump over’ intervening boundaries and activate the Abd-B promoter. In the studies reported here we have investigated the parameters governing bypass activity. We find that the bypass elements in the Fab-7 and Fab-8 boundaries must be located in the regulatory domain that is responsible for driving Abd-B expression. We suggest that bypass activity may also be subject to regulation.
显示更多 [+] 显示较少 [-]