McCann S H, Eresh S, Barker D C
Department of Pathology, University of Cambridge.
Parasitology. 1999 Apr;118 ( Pt 4):371-4. doi: 10.1017/s0031182098003916.
To investigate the phenomenon that PCR of Leishmania (V.) lainsoni minicircles using primers B1 and B2 gives anomalous small-sized products, unlike all other members of the Leishmania Viannia subgenus, cloned kDNA minicircles from L. (Viannia) lainsoni were sequenced using fluorescent dye terminator reactions. The sequence of L. (V.) lainsoni where the primer B2 would be expected to bind, was different from the other members of the L. Viannia subgenus, matching in only 7 out of 19 bases with the sequence of L. (V.) braziliensis at this position. The sequence obtained from the cloned minicircles enabled the design of a new primer which, when combined with B1, allowed the amplification of full sized minicircles in L. (V.) lainsoni, but not other members of the L. Viannia subgenus. Comparison of the sequence obtained for Leishmania (V.) lainsoni with other Leishmania minicircle DNA confirms that Leishmania (V.) lainsoni is more similar to members of the L. Viannia subgenus than to other Leishmania, but is distinctly different.
为了研究使用引物B1和B2对莱氏利什曼原虫（Viannia亚属）微小环进行PCR时出现异常小尺寸产物的现象，与维氏利什曼原虫亚属的所有其他成员不同，我们使用荧光染料终止反应对来自莱氏利什曼原虫（Viannia亚属）的克隆动质体微小环进行了测序。在预期引物B2会结合的莱氏利什曼原虫（Viannia亚属）序列中，与维氏利什曼原虫亚属的其他成员不同，在该位置与巴西利什曼原虫（Viannia亚属）的序列仅19个碱基中有7个匹配。从克隆的微小环获得的序列使得能够设计一种新引物，当与B1结合使用时，该引物能够扩增莱氏利什曼原虫（Viannia亚属）中的全长微小环，但不能扩增维氏利什曼原虫亚属的其他成员。将莱氏利什曼原虫（Viannia亚属）获得的序列与其他利什曼原虫微小环DNA进行比较证实，莱氏利什曼原虫（Viannia亚属）与维氏利什曼原虫亚属的成员比与其他利什曼原虫更相似，但明显不同。
