Table 4.

Effects of drug treatments on Nodal and Lefty laterality and organ situs and the degree of repair of incorrect laterality, calculated as the percentage of embryos with incorrect Nodal expression that have correct organ situs, using separate clutches for each analysis. GR113808: serotonin receptor blocker; iproniazid: monoamine oxidase inhibitor. R: right; Bi: bilateral; N: none. Degree of repair for GR113808 indicates that defects in Nodal and organ situs are the same but that Lefty is bypassed. Degree of repair for Iproniazid indicates that defects in early laterality markers are being corrected by the point of organ placement.

drug treatment	incorrect Nodal expression	incorrect Lefty expression	reversed organs	references	degree of repair
GR113808	43% (R: 10%, Bi: 26%, N: 7%) n = 150	14% (R: 3%, Bi: 2%, N: 9%) n = 164	44% n = 269	[144]	−2%
iproniazid	43% (R: 10%, Bi: 21%, N: 13%) n = 135	15% (R: 2%, Bi: 4%, N: 10%) n = 191	30% n = 387	[144]	30%