Variation of nanomechanical properties of bone by gene mutation in the zebrafish

Significant variations of nanomechanical properties and fracture morphology between gene-mutated liliput(dtc232) (lilllil) zebrafish skeletal bone and wild-type bone have been observed. Nanoindentation measurement disclosed that lilllil bone has 36% lower nanohardness and 32% lower elastic modulus. The standard deviations of hardness and elastic modulus of lilllil bone were both much higher than those of wild-type bone. SEM morphology of fracture surfaces further revealed that in bones after gene mutation, formative microcracks make the performance reduction and the increasing of brittleness. What is more, the plywood-like structure of the normal bone does not exist in the lilllil bone. (C) 2002 Elsevier Science Ltd. All rights reserved.