Structure and expression of zebrafish Tpo. (A) Protein structure diagram of human (top) and zebrafish (bottom) Tpo. Black boxes represent the leader sequence, open boxes represent the conserved Epo/Tpo domain, Cs represent conserved Cys residues, *s represent glycosylation sites, and the gray box represents the C-terminal TPO domain found only in mammals. Modified from Bartunek et al.2 (B) Overall structure and secondary-structure elements of zebrafish Tpo, protein is represented as a ribbon diagram. (C) qRT-PCR analysis of tpo levels in adult organs. Tissues are listed along x-axis. The fold change in the expression is relative to kidney marrow, defined as “1.” Bars represent the mean values of 3 biological samples, with error bars representing standard deviation.