荚膜组织胞浆菌是呼吸系统真菌病病原体,在土壤中以腐生霉菌型存在,吸入肺内后,则以单细胞酵母型存在。酵母型菌能在缺钙的环境中生长,并分泌相对分子质量(Mr)为7.8×10~3的钙结合蛋白(CBP);而霉菌型生长需要钙,不分泌CBP。为了证实CBP在钙需求和(或)致病性关系,作者设计了一个剔除cbp1基因的策略,即利用线形端粒质粒(PTS100)和二步遗传选择法进行等位基因 Histoplasma capsulatum is a pathogen of respiratory fungal disease in the soil to the presence of saprophytic bacteria, inhaled into the lung, the single-cell yeast exists. Yeast-type bacteria can grow in a calcium-deficient environment and secrete calcium-binding protein (CBP) with a relative molecular mass (Mr) of 7.8 × 10 -3; whereas mold growth requires calcium without CBP secretion. In order to confirm CBP’s calcium requirement and / or pathogenicity, the authors devised a strategy for knocking out the cbp1 gene, alleles using linear telomeric plasmids (PTS100) and two-step genetic selection