Herbert R G, Pasternak J J, Fernando M A
Department of Pathology, University of Guelph, Ontario, Canada.
J Parasitol. 1992 Dec;78(6):1011-8.
A cDNA library was constructed with poly(A)+ RNA from unsporulated oocysts of Eimeria tenella in pUC18. After screening, 4 cDNA clones that hybridized to RNA of unsporulated and sporulating oocysts but not to RNA of either sporulated oocysts or second generation merozoites were isolated and characterized. Each of the cDNA clones is unique. The loci for 2 of the clones are on E. tenella chromosome 7, the site of the third is located on chromosome 6 and the last clone hybridizes, for the most part, to chromosome 5 but also to other E. tenella chromosomes. The cognate RNAs for each of the cDNA clones show differential patterns of hybridization during oocyst sporulation with the levels of RNA being low at the start of sporulation (0 hr), increasing to peak levels between 6.5 and 23 hr after the onset of sporulation and, in each case, decreasing to low hybridization levels at 48 hr after initiation of sporulation. These results establish that specific mRNA levels are differentially regulated during sporulation.
用来自柔嫩艾美耳球虫未孢子化卵囊的聚腺苷酸加尾RNA在pUC18载体中构建了一个cDNA文库。筛选后，分离并鉴定了4个与未孢子化和正在孢子化的卵囊RNA杂交，但不与孢子化卵囊或第二代裂殖子RNA杂交的cDNA克隆。每个cDNA克隆都是独特的。其中2个克隆的基因座位于柔嫩艾美耳球虫的7号染色体上，第3个克隆的位点位于6号染色体上，最后一个克隆大部分与5号染色体杂交，但也与柔嫩艾美耳球虫的其他染色体杂交。每个cDNA克隆的同源RNA在卵囊孢子化过程中呈现出不同的杂交模式，RNA水平在孢子化开始时（0小时）较低，在孢子化开始后6.5至23小时之间增加到峰值水平，并且在每种情况下，在孢子化开始后48小时降至低杂交水平。这些结果表明，在孢子化过程中特定mRNA水平受到差异调节。
