Region from -483 bp upstream the +1 to the first 17 codons is the minimal enhancer which drives the entire Ci-Bra expression (the transcription start site is the nucleotide +1).

This region contains three essential cis-regulatory elements.

Region - 483 bp/- 348 bp : negative response that keeps the enhancer off in ectopic mesodermal lineage (muscles and mesenchyme). This region contains three copies of a conserved 15 bp sequence motif. It is currently unclear whether this repeat is important for repression.

Region -348 bp/ - 237 bp : it contains one, or possibly two, Su(H) binding sites. Removal of these sites significantly decreases expression in the notochord.

Region - 237 bp/- 71 bp : it contains important element for activation in the mesenchyme and muscles. This region contains three E-box sequences. Progressive truncations that remove these sequences lead to a sequential loss of expression in ectopic mesodermal lineage.

Modification of Ci-Bra -143/17 first codons by deletion

KH2012:KH.S1404.1 (TBX19; TBX6; TBXT)

CONS00000112: pBra -71/17 first codons::LacZ

6,2006,292

Aniseed Coordinates: [6,200 / 6,292] on scaffold KhS1404

This sequence was found using a blast on the JGI V1.0 using sequences included in Corbo et al. (1997 and 1998), Fujiwara et al. (1998) and Yagi et al (2004). The basal promoter of Ci-Bra (-68 to +26) was cloned between the Pst1 and BamH1 sites of the p72-1.27 vector: Pst1 - pBra(-68/+26) - BamH1

Oda-Ishii et al. (2016). A Maternal System Initiating the Zygotic Developmental Program through Combinatorial Repression in the Ascidian Embryo. PLoS Genet. 12(5):e1006045

Corbo et al. (1997). Characterization of a notochord-specific enhancer from the Brachyury promoter region of the ascidian, Ciona intestinalis. Development 124(3):589-602