Objective   To clone prostaglandin E synthase 3a (ptges3a) gene and investigate its temporal and spatial expression pattern in zebrafish during early development.   Methods   The total RNA of different phases of zebrafish embryos was extracted. Digoxin-labeled RNA probe of ptges3a was prepared. Whole embryo mount in situ hybridization was employed to investigate the expression pattern of ptges3a during zebrafish embryogenesis.    Results   ptges3a transcript was distributed ubiquitously before shield stage. At 10-somite there were detectable expression of ptges3a gene in the hindbrain neural keel

and at 18-somite it was expressed in the hindbrain. From 26 to 36 h after post fertilization (hpf)

high expression of ptges3a was found in the brain. ptges3a was also detectable in the renal tubule at 26 hpf.   Conclusion   The expression pattern of ptges3a during zebrafish embryogenesis suggests that it may be critical for the development of brain and renal tubule. Further investigation on the function of ptges3a is needed.