Gal4 System   |   Targeted DamID   |   Chromatin DamID   |   RNA DamID   | MAMMALIAN TADA |   PROTOCOLS & PIPELINES


Targeted DamID.png

Targeted DamID

Cell-type-specific profiling of gene expression and chromatin binding without cell isolation: assaying RNA Pol II occupancy in neural stem cells
Southall TD, Gold KS, Egger B, Davidson CM, Caygill EE, Marshall OJ and Brand AH (2013) Developmental Cell

Targeted DamID (”TaDa”) is based on DNA adenine methlyltransferase identification (DamID). The Escherichia coli DNA adenine methyltransferase (Dam) protein is fused to a DNA- or chromatin-binding protein of interest and the resulting fusion protein methylates binding sites in the genome. Importantly, DamID requires the Dam-fusion protein to be expressed at extremely low levels to avoid toxicity and nonspecific methylation

In TaDa, the conditional (”targeted”) expression of the Dam-fusion is achieved using the GAL4 system. The introduction of a primary ORF before the Dam-fusion, combined with low rates of translation reinitiation, results in low level expression of the Dam-fusion in a cell-type-specific manner.

TaDa has many advantages: it is robust and reproducible and requires no crosslinking, immunoprecipitation or cell sorting. It can be completed in 3 days from start to finish and can be performed with fewer than 10,000 cells.

See also NanoDam (coming soon), the adaptation of TaDa that bypasses the need for the generation of Dam fusion proteins.

Available reagents (require MTA):

Please contact Andrea Brand a.brand@gurdon.cam.ac.uk

  • pUAST-LT3-Dam plasmid plasmid map

  • pUAST-LT3-Dam-Pol II plasmid plasmid map

  • UAS-LT3-Dam Drosophila line

  • UAS-LT3-Dam-Pol II Drosophila line

Reagents for profiling chromatin-binding proteins with TaDa can be found here