Figure 1.

Large Reporter Constructs Show Distinct Roles for Three Early CRMs

(A) We created a 32 kb reporter construct, which encompassed the three identified early CRMs and surrounding sequence (extent shown by blue lines in A) and was able to rescue the mutant phenotype. All but the first 66 amino acids of the brk coding sequence was replaced by gfp, creating a nonfunctional reporter construct used for cis-regulatory analysis. Deletions of each of the CRMs were made where indicated by breaks in the blue line.

(B–G) In situ hybridization was performed using riboprobes to detect either brk transcript in wild-type embryos (B) or gfp transcript in transgenic embryos (C–G). The reporter construct expression patterns were compared to the endogenous brk pattern at three stages of development: precellularization (B–G), cellularization (B′–G′), and gastrulation (B″–G″). In this and subsequent figures, embryos are oriented with anterior to the left, dorsal up, and are ventrolateral surface views.

See also Figure S1.