Fig. 2

Defective development of lymphatic vessels in zebrafish embryos treated with cigarette smoke extract or snuff extract. (A) Confocal micrographs of the central trunk region in fli1a:EGFP transgenic zebrafish at 4days post-fertilization (dpf) treated with nothing (control), cigarette smoke extract (CS) at 1:30 dilution or snuff extract at 1:50 dilution. White boxes in the left column represent the areas enlarged in the right column. ISV, inter-segmental vessel; DA, dorsal aorta; TD, thoracic duct; PCV, posterior cardinal vein; IV, intestinal vein. White stars represent the area in which the thoracic duct should have appeared but is lacking. (B) Quantification of the proportion of non-treated, CS extract-treated or snuff extract-treated embryos with an absent or major defect in TD development at 4dpf. n=160 embryos. **P<0.01, ***P<0.001. (C) Bright-field micrographs of zebrafish larvae at 4dpf treated with nothing (top image), CS extract (middle image) or snuff extract (bottom image). Green arrows indicate the pericardium, with pericardial edema visible in the CS and snuff groups. (D) Quantification of the proportion of non-treated, CS extract-treated or snuff extract-treated embryos with pericardial edema at 4dpf. n=110 embryos. *P<0.05. All experiments were repeated twice with similar results. Results are shown as means±s.e.m. and statistical evaluation was done using Student’s two-tailed t-test assuming equal variance between the groups.