Welcome to AlHaj Abed Lab
We are interested in understanding how maternal and paternal chromosomes communicate using genome-wide sequencing approaches and super-resolution imaging. Our lab aims to provide a better understanding of the fundamental mechanisms governing homologous chromosome 3D structure in the nucleus and how that contributes to gene regulation.
Our research aims to understand the mechanisms of paternal and maternal chromosome communication by investigating parental chromosome organization and how it contributes to gene function.
i) How are the different layers of organization formed and maintained during transcriptional switches and development, ii) what are the major factors and dynamics facilitating these changes, and iii) how can we apply these tools to understand other concepts of genome organization in healthy and disease states.
Structure & Function
What is the contribution of chromosome structure i) at the gene regulatory level, and ii) within tissue-specific contexts?
Mechanism & Dynamics
i) What are the major driving factors of pairing events?
ii) What are the step-by-step events leading to trans-homolog contacts?
Can we apply these tools to understand i) other pairing events and ii) large chromosomal abnormalities?
Project 1: Structure & Function
De novo recruitment of Polycomb proteins and epigenetic switches during embryogenesis
Early embryogenesis in Drosophila is marked by major epigenetic changes and genome reorganization. Previously, using the Drosophila genetic system AlHaj Abed et al, 2018, revealed de novo Polycomb Group protein (PcG) recruitment by a time-course ChIP assay as (PcG) protein repression takes over from local transcription factors during development. The study reveals that PcG-mediated repression proceeds through a sampling phase (i) followed by a more stable localization of DNA-binding complex PhoRC and PRC2 (ii) and finally a stable binding of PRC2, deposition of H3K27me3 repressive mark and PRC1 (iii).
We are interested in examining the role of cis and trans regulatory architecture of genes and understanding these epigenetic switches in other context during development.