HSPG Regulates Trans-Synaptic Signaling Figure 7. WNT and BMP signals genetically interact with sulf1 and hs6st nulls. Genetic reduction of Wg and Gbb levels in sulf1 and hs6st homozygous conditions restore EJC amplitudes to control levels. (A) Representative excitatory junctional current (EJC) traces from control (w1118), PLOS Genetics | www.plosgenetics.org 13 November 2012 | Volume 8 | Issue 11 | e1003031