Eresh S, Mendoza-Leòn A, Barker D C
MRC Outstation of NIMR, Molteno Laboratories, Department of Pathology, University of Cambridge, UK.
Acta Trop. 1993 Oct;55(1-2):33-46. doi: 10.1016/0001-706x(93)90046-e.
Orthogonal Field Alternating Gel Electrophoresis (OFAGE) has been used to show a band of approximately 260 kb which is stained intensely with ethidium bromide in Leishmania (V.) braziliensis stock M2903. This small chromosome (sc-2903), as well as a 50 kb and a 200 kb chromosome seen in L. (L.) mexicana and L. (L.) amazonensis, respectively, are stably maintained and linear. When used as a hybridisation probe, sc-2903 showed homology to large chromosomal DNA bands and to a multiplicity of genomic fragments in all braziliensis stocks tested, indicating either different sequences, different copy numbers or both but no hybridisation to mexicana stocks. It is possible that these sequences are present in all members of the braziliensis complex and are not related to LD1 or any other previously published small chromosome sequences. However, at least one clone isolated from a sc-2903 library recognised genomic DNA of stocks belonging to the braziliensis, mexicana and donovani complexes. Our results suggest that the clone carries sequence(s) that are repeated and shared between stocks of different complexes but with a variable genomic distribution.
正交场交变凝胶电泳（OFAGE）已被用于显示在巴西利什曼原虫（V.）M2903株中一条约260 kb的条带，该条带被溴化乙锭强烈染色。这条小染色体（sc-2903），以及分别在墨西哥利什曼原虫（L.）和亚马逊利什曼原虫（L.）中看到的一条50 kb和一条200 kb的染色体，都是稳定维持的且呈线性。当用作杂交探针时，sc-2903与所有测试的巴西利什曼原虫株中的大染色体DNA条带和多种基因组片段显示出同源性，这表明存在不同的序列、不同的拷贝数或两者皆有，但与墨西哥利什曼原虫株没有杂交。这些序列有可能存在于巴西利什曼原虫复合体的所有成员中，并且与LD1或任何其他先前发表的小染色体序列无关。然而，从sc-2903文库中分离出的至少一个克隆识别属于巴西利什曼原虫、墨西哥利什曼原虫和杜氏利什曼原虫复合体的株系的基因组DNA。我们的结果表明，该克隆携带的序列在不同复合体的株系之间重复且共享，但基因组分布可变。
