Miska K B, Fetterer R H, Barfield R C
USDA-ARS, Animal Parasitic Diseases Laboratory, 10300 Baltimore Avenue, Building 1042 BARC-East, Beltsville, Maryland 20705, USA.
J Parasitol. 2004 Dec;90(6):1245-52. doi: 10.1645/GE-309R.
To characterize the genes expressed by Eimeria tenella oocysts, the sequence of 499 expressed sequence tags (ESTs) was obtained from complementary DNA (cDNAs) enriched for transcripts expressed by unsporulated or sporulated oocysts. Of these, 225 clones were isolated from cDNA of sporulated oocysts and 274 from unsporulated oocysts. A total of 163 unique sequences were found, and the majority of these (64%) represent novel genes with no significant homology to the proteins in GenBank. Approximately half of the unique transcripts generated from sporulated oocysts are also expressed by sporozoites and merozoites, whereas the expression of most (79%) of the transcripts from unsporulated oocysts has not yet been detected at other stages of development. The expression of 4 transcripts obtained from the subtracted cDNAs was confirmed by quantitative reverse transcriptase-polymerase chain reaction. The results confirmed that these transcripts are in fact differentially expressed between sporulated and unsporulated oocysts.
为了鉴定柔嫩艾美耳球虫卵囊表达的基因，从富含未孢子化或孢子化卵囊表达转录本的互补DNA（cDNA）中获得了499个表达序列标签（EST）的序列。其中，225个克隆是从孢子化卵囊的cDNA中分离得到的，274个是从未孢子化卵囊的cDNA中分离得到的。共发现163个独特序列，其中大多数（64%）代表与GenBank中的蛋白质无显著同源性的新基因。孢子化卵囊产生的独特转录本中约有一半也由子孢子和裂殖子表达，而未孢子化卵囊的大多数转录本（79%）在发育的其他阶段尚未检测到表达。通过定量逆转录-聚合酶链反应证实了从扣除cDNA中获得的4个转录本的表达。结果证实，这些转录本实际上在孢子化和未孢子化卵囊之间存在差异表达。
