Zebrafish Smooth Muscle-specific Gene Sm22¦Á Cloning, Expression And Functional Studies

(1)Zebrafish is a newly-developed model organism system to study embryogenesis of the vertebrates.Whole mount in situ hybridization and transgene via microinjection are two important methods in zebrafish study. In this part, cDNA fragment of zebrfsih GATA-I and biklf which are specifically expressed in zebrafish hematopoiesis system are used as probes to carry on whole amount in situ hybrizidation.The results suggest that they are both detected in zebrafish hematopoesis system during the embryogenesis.But GATA-1 gene expression pattern is restricted strightly in the erythrocyte and emerges lately than biklf which can be detected just after accomplishment of MBT. However, except for expression in hematopoiesis system, biklf is also observed in some ectoderm tissues.Then we transport reporter gene driven by CMV promoter and erythrocyte- specific GATA-1 promoter into the embryos via microinjection approach and observed the spatial and temporal expression pattern of EGFP. We find that EGFP is found express abundantly during embryo development under the control of CMV promoter while the expression pattern of GATA-l-EGFP can mimic the endogenous GATA-1 gene expression pattern. Our results demonstrate that an efficient and reliable technology of whole amount in situ hybridization and microinject transgene in zebrafish are established.(2)SM22a is a kind of 22-kDa cytoskeleton-related protein which is exclusively expressed in smooth muscle containing tissues of the vertebrates. Here we report molecular cloning of a novel zebrafish SM22a gene. We observe its expression pattern during embryogenesis through whole mount in situ hybridization. In order to explore the biological function of SM22a during zebrafish embryo development, we adopte the gene-specific morpholino modified antisense oligo to carry out gene knock-down assay and analysis its influence to zebrafish embryogenesis.The full length of zebrafish SM22a cDNA is 1296 bp and its ORF encodes a polypeptide of 201 amino acids which shares 69.2%, 69.7%, 69.2%, 67.2%, and 61.2% overall identity with human, mouse, rat, chicken, and bovine SM22a, respectively.The product of SM22a gene contains a Calponin Homologue domain and calponin tandem repeat which are...