Department of

The BEN Domain Protein Insensitive Binds to the Fab-7 Chromatin Boundary To Establish Proper Segmental Identity in Drosophila

Boundaries (insulators) in the bithorax complex (BX-C) delimit autonomous regulatory domains that orchestrate the parasegment (PS)-specific expression of the BX-C homeotic genes. The boundary separates the and regulatory domains, which control Abd-B expression in PS11 and PS12, respectively. This boundary is composed of multiple functionally redundant elements and has two key functions: it blocks crosstalk between and and facilitates boundary bypass. Here, we show that two BEN domain protein complexes, Insensitive and Elba, bind to multiple sequences located in the nuclease hypersensitive regions. Two of these sequences are recognized by both Insv and Elba and correspond to a CCAATTGG palindrome. Elba also binds to a related CCAATAAG sequence, while Insv does not. However, the third Insv recognition sequences is ~100 bp in length and contains the CCAATAAG sequence at one end. Both Insv and Elba are assembled into large complexes (~420 kD and ~265-290 kD, respectively) in nuclear extracts. Using a sensitized genetic background we show that the Insv protein is required for boundary function, and that PS11 identity is not properly established in mutants. This is the first demonstration that a BEN domain protein is important for the functioning of an endogenous fly boundary.

The origin of the mammalian brain uncovered

The expression levels of three genes determines the predominant mode of neurogenesis and the development the cerebral neocortex in mammals

Phytochrome and plant defenses

29.08.2018 12:15, 1S059 (Sciences III)

Carlos Ballaré (UBA - Universitiy of Buenos Aires).
hosted by: Roman Ulm.