Duplication of the IGFBP-2 Gene in Teleost Fish: Protein Structure and Functionality Conservation and Gene Expression Divergence
Figure 6
The growth inhibitory effect of IGFBP-2 is evolutionarily conserved and is dependent on its IGF binding but not its interaction with heparin or integrin.
A) A schematic diagram showing the native and mutant IGFBP-2 structure. The ligand binding mutant (LBDm) was engineered following Forbes et al. [6], heparin binding domain mutant (HBDm) following Russo et al. [22], and RGD mutant (RGDm) following Wang et al. [23]. B) Effects of expression of proteins shown in A) on embryo growth and developmental rate in vivo. Capped mRNA (800 pg/embryo) was injected into 1–2 cell stage embryos. The embryos were raised to 24 hpf and body length and somite number were determined. Results are from three independent microinjection experiments. The total embryo number for each group is 91(gfp), 94 (higfbp2), 131 (LBDm), 79 (HBDm), and 81(RGDm). Values are represented as Means±S.E. (n = 3). Groups with common letters are not significantly different from each other (p<0.05).