Expression of Heat Shock Protein 27 and Alpha B Crystallin in the Retina and Optic Nerve of the Chick Embryo

Heat shock protein 27 (HSP27) and alpha B crystallin (aBC) belong to the small heat shock protein (sHSP) family and have similar amino acid sequences. However, no study has compared the distributional patterns of these two sHSPs in the retina and optic nerve. In this study, we compared the spatiotemporal distributions of the expressions of HSP27 and aBC in the developing chick retina and optic nerve. Both HSP27 and aBC were first expressed in the retina and optic nerve at embryonic day 16 (E16). At E20 the expressions of the two proteins were increased in the retina and optic nerve. Double immunofluorescence demonstrated that HSP27 and aBC were expressed in oligodendrocytes of the retina and optic nerve. In addition, HSP27 was also found to be expressed in ganglion cells in the retina. The findings of this study suggest that HSP27 and aBC act to protect ganglion cells and oligodendrocytes during late development of the chick retina and optic nerve.