目的　在乳酸乳球菌中表达ROP1抗原蛋白。方法　从质粒 psk -ROP1中以BamHⅠ和SalⅠ双酶切出ROP1基因 ,置换构建好的大肠杆菌 -乳酸乳球菌穿梭表达质粒L2 -PsP30T中的P30基因 ,电转化感受态乳酸乳球菌 ,以Westernblotting鉴定ROP1在乳酸乳球菌中的表达。结果　表达产物中有一约 4 3kDa的蛋白带能被弓形虫病人血清识别。结论　ROP1在乳酸乳球菌中得到了表达 Objective To express ROP1 antigen protein in Lactococcus lactis. METHODS: The ROP1 gene was cut out from the plasmid psk -ROP1 by double enzyme digestion with BamHⅠ and SalⅠ. The P30 gene in the Lactococcus lactis shuttle expression plasmid L2 -PsP30T was replaced by the recombinant plasmid psk -ROP1. The competent Lactococcus lactis was electroporated and identified by Western blotting ROP1 expression in Lactococcus lactis. As a result, a protein band of about 43 kDa in the expression product was recognized by the serum of Toxoplasma gondii. Conclusion ROP1 was expressed in Lactococcus lactis