Abstract:The sclerostin (SOST) is a factor that is specifically secreted by bone cells for negative regulation of bone formation. In order to explore the regulatory function of the gene SOST during the intermuscular thorn formation of Carassius auratus, we cloned the gene and constructed the prokaryotic expression vector pET-32 a (+) -SOST successfully. Then the recombinant plasmids were transferred into E.coli BL21 (DE3) and induced by IPTG to count the protein expression. Meanwhile, using the SOST gene without the endogenous signal peptide, we check the protein expression again. It is respectably reflected that the length of the gene is about 636 bp and its protein weight is 38 kDa. Additionally, the induction of time did have an influence on the protein expression. After the SDS-PAGE, we found that the exist of endogenous signal peptide strong inhibits to protein prokaryotic expression. What's more, the concentration of IPTG has little effect on it while the protein expression became stable after 4 h induction in the time gradient. This experiment can provides more theoretical evidence for further analysis about SOST gene on the Carassius auratus intermuscular thorns formation mechanism.