Figure 2

Expression of left-sided Nodal signaling in LPM. (A. a1-a4, B) Expression of left-sided spaw in embryos. In control embryos, near all the embryos expressed left-sided spaw (A. a1, 91.4%, n=93). While in aplnra and aplnrb morphants, left-sided spaw expression pattern was changed (A. a2-a4, B), 13.6% (p>0.05), 7.8% and 47.6% (p<0.001) of aplnra morphants expressed right-sided, both-sided spaw or spaw disappeared (B, middle-left column, n=103). 10.2 % (p<0.05) and 6.1% (p>0.05) of aplnrb morphants showed right-sided and both sided spaw (B, middle-right column, n=98), majority of aplnrb morphants showed no staining for spaw (B, middle-right column, n=98, p<0.001). (C. c1-c4, D) The expression of left-sided lft2 in the heart progenitor field. In the control embryos, lft2 was expressed in the left side of heart progenitor field (C.c1, 94.2%, n=52). Lft2 was down-regulated in aplnra morphants (C. c2-c4), the left-sided expression pattern was also perturbed (C. c2-c4, D), with 9.0%, 6.3% and 52.5% of embryos showing right-sided, both-sided lft2 and lft2 disappeared, respectively (C. c2-c4; D, middle column, n=74). The lft2 expression pattern in aplnrb morphants (D, right column, n=93) was similar to that in aplnra morphants (D, middle column, n=74), but more embryos had no staining for lft2 in aplnrb morphants (D, right column, n=93) than in aplnra morphants (D, middle column, n=74). All the embryos were observed from dorsal view. L, Left; R, Right.