中文摘要：

浆液联系抵抗(SRA ) 蛋白质，为 Trypanosoma brucei rhodesiense 唯一的蛋白质，为到由正常人的浆液(NHS ) 的细胞溶解的这个寄生虫的抵抗负责并且是一个重要分子的标记把这种与另外的非洲的睡病虫区分开来。我们克隆并且定序 SRA 从 T 的基本拷贝(SRAbc ) 基因。b。rhodesiense 和相关种类并且发现这基因被限制到亚属 Trypanozoon。一般水准在定序的 SRAbc 基因之中的 82% 身份显示他们可以有普通起源并且高度被保存。自从 SRAbc，在 T 共存。b。有 SRA 的 rhodesiense 染色体，我们建议 SRAbc 可能是‘ d 在上或 VSG' ，它在复制变得由再结合插入了到表示地点以后。在自然选择下面， SRAbc 能改过进 SRA 后面的马赛克形成。

英文摘要：

Serum resistance-associated （SRA） protein, a protein unique for Trypanosoma brucei rhodesiense, is responsible for resistance of this parasite to the lysis by normal human serum （NHS） and is a vital molecular marker to distinguish this species from other African trypanosomes. We cloned and sequenced the SRA basic copy （SRAbc） gene from T. b. rhodesiense and related species and found that this gene is confined to the subgenus Trypanozoon. The average 82% identity among the sequenced SRAbc genes indicates that they may have a common origin and are highly conserved. Since SRAbc coexists in the T. b. rhodesiense genome with SRA, we propose that SRAbc might be the ‘donor VSG＇, which after duplication became inserted into the expression site by recombination. Under natural selection, SRAbc could reform into SRA following mosaic formation.