Frothingham R
Infectious Disease Section, Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA.
Med Hypotheses. 1999 Feb;52(2):95-9. doi: 10.1054/mehy.1997.0622.
Parasitic mycobacteria cause important human and animal diseases including tuberculosis, leprosy, and paratuberculosis. Several methods demonstrate a high degree of sequence conservation in three parasitic mycobacterial species (Mycobacterium tuberculosis, M. leprae, and M. avium subspecies paratuberculosis). Each of these species has completely conserved deoxyribonucleic acid (DNA) sequence in an internal transcribed spacer. In contrast, several species of environmental mycobacteria (M. intracellulare, M. kansasii, M. gordonae, and M. scrofulaceum) have substantial strain-to-strain variation in this region. These data suggest that each of the parasitic species has gone through a recent evolutionary bottleneck. Comparisons of tandem-repeat DNA from ancient and modern mycobacterial strains may allow this hypothesis to be tested directly.
寄生性分枝杆菌会引发包括结核病、麻风病和副结核病在内的重要人类和动物疾病。有几种方法表明，三种寄生性分枝杆菌（结核分枝杆菌、麻风分枝杆菌和副结核分枝杆菌鸟亚种）具有高度的序列保守性。这些物种中的每一个在内部转录间隔区都有完全保守的脱氧核糖核酸（DNA）序列。相比之下，几种环境分枝杆菌（胞内分枝杆菌、堪萨斯分枝杆菌、戈登分枝杆菌和瘰疬分枝杆菌）在该区域存在显著的菌株间差异。这些数据表明，每一种寄生性物种都经历了近期的进化瓶颈。对古代和现代分枝杆菌菌株的串联重复DNA进行比较，可能会直接验证这一假说。
