The characterization of female-specific gene fs 800 in Schistosoma

虫对产卵是血吸虫病发病的一个主要原因。因此，了解女性生殖发育，特别是女性特异性基因调控机制对疾病控制具有重要意义。先前分离的编码fs 800蛋白的cDNA被用于鉴定和分离含有fs 800基因完整拷贝的重组噬菌体。该基因包含在一个5.5 kbp的EcoRI片段上。没有内含子。以RNA为模板，通过引物延伸和双脱氧测序确定mRNA的cap-site。该基因的上游区域包含假定的顺式作用元件（TCACGT， GTAGAAT），这些元件已被证明在调节昆虫的绒毛膜基因表达中发挥作用。还发现了具有共同核心基序TRRAAT（R=嘧啶）的其他元素。这些元件已被证明与核蛋白结合并控制家蚕报告基因表达的定量和定性变化。

Egg production of worm pairs is a major cause of pathogenesis in schistosomiasis. Thus an understanding of female reproductive development, especially mechanisms of female-specific gene regulation is of major importance in disease control. A previously isolated cDNA that encodes the fs 800 protein was used to identify and isolate a recombinant phage containing an entire copy of the fs 800 gene. The gene is contained on a 5.5 kbp EcoRI fragment. There are no introns. The cap-site of the mRNA was determined by primer extension using RNA as template and dideoxy sequencing. The upstream regions of the gene contain putative cis-acting elements (TCACGT, GTAGAAT) that have been shown to play a role in the regulation of chorion gene expression in insects. The other elements that share a common core motif, TRRAAT(R=pyrimidine), are also found. These elements have been shown to bind nuclear proteins and control quantitative and qualitative changes in reporter gene expression in silkmoths.