Abstract: AIM: To construct and identify the mammary gland cell-specific conditional knockout of SENP7 by the Cre-loxP system.  METHODS: The homozygous SENP7flox/flox mice were generated by crossing SENP7flox/+ mice. Genotypic identification was performed by PCR. SENP7flox/flox mice and MMTV-Cre mice had reproduced and genotyped respectively, then the two strains of mice were crossed. The MMTV-Cre×SENP7flox/flox mice were the required mouse model. Real-Time PCR, Western blot and HE staining were applied to identify the knockout effect of SENP7 and to observe the morphology of mammary gland tissue. RESULTS: PCR analysis selected MMTV-Cre×SENP7flox/flox mice. Compared to the MMTV-Cre×SENP7+/+ mice, expression levels of SENP7 mRNA and protein of mammary glands were significantly lower in MMTV-Cre×SENP7flox/flox mice, and the number of mammary glands was significantly reduced, suggesting the SENP7 knockout effect was obvious. CONCLUSION: The mammary cell-specific deletion of the SENP7 gene is successfully constructed by Cre-loxP system, which provides a novel target for studying the pathogenesis of breast tumors at animal level.

Key words: SENP7, Cre-loxP system, MMTV-Cre, mammary gland