Asymmetric and node-specific nodal (ital) expression patterns are controlled by two distinct cis-acting regulatory elements

Node-specific and asymmetric nodal expression patterns are regulated by two cis-acting regulatory elements distinct from one another. The cis-regulatory elements that control nodal (ital) expression domains in early development have been analyzed. Regulatory sequences that confer node-specific expression are in an upstream region of the locus. Early expression in the epiblast and endoderm and asymmetric expression at later stages on the left side of the axis of the body are controlled by a 600-bp intronic enhancer. Developmentally regulated nodal (ital) expression at certain tissue locations in left-right (L-R) and anterior-posterior (A-P) formation is potentially controlled by shared transcriptional activators.