School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor DE, Malaysia.
BMC Genomics. 2012 Jan 13;13:21. doi: 10.1186/1471-2164-13-21.
Eimeria tenella is an apicomplexan parasite that causes coccidiosis in the domestic fowl. Infection with this parasite is diagnosed frequently in intensively reared poultry and its control is usually accorded a high priority, especially in chickens raised for meat. Prophylactic chemotherapy has been the primary method used for the control of coccidiosis. However, drug efficacy can be compromised by drug-resistant parasites and the lack of new drugs highlights demands for alternative control strategies including vaccination. In the long term, sustainable control of coccidiosis will most likely be achieved through integrated drug and vaccination programmes. Characterisation of the E. tenella transcriptome may provide a better understanding of the biology of the parasite and aid in the development of a more effective control for coccidiosis.
More than 15,000 partial sequences were generated from the 5' and 3' ends of clones randomly selected from an E. tenella second generation merozoite full-length cDNA library. Clustering of these sequences produced 1,529 unique transcripts (UTs). Based on the transcript assembly and subsequently primer walking, 433 full-length cDNA sequences were successfully generated. These sequences varied in length, ranging from 441 bp to 3,083 bp, with an average size of 1,647 bp. Simple sequence repeat (SSR) analysis identified CAG as the most abundant trinucleotide motif, while codon usage analysis revealed that the ten most infrequently used codons in E. tenella are UAU, UGU, GUA, CAU, AUA, CGA, UUA, CUA, CGU and AGU. Subsequent analysis of the E. tenella complete coding sequences identified 25 putative secretory and 60 putative surface proteins, all of which are now rational candidates for development as recombinant vaccines or drug targets in the effort to control avian coccidiosis.
This paper describes the generation and characterisation of full-length cDNA sequences from E. tenella second generation merozoites and provides new insights into the E. tenella transcriptome. The data generated will be useful for the development and validation of diagnostic and control strategies for coccidiosis and will be of value in annotation of the E. tenella genome sequence.
柔嫩艾美耳球虫是一种顶复门寄生虫，会导致家禽的球虫病。这种寄生虫的感染在集约化饲养的家禽中经常被诊断出来，其控制通常被视为重中之重，尤其是在用于生产肉类的鸡中。预防性化疗一直是控制球虫病的主要方法。然而，耐药寄生虫可能会影响药物疗效，而新药物的缺乏则凸显了对替代控制策略的需求，包括疫苗接种。从长远来看，通过综合药物和疫苗计划，极有可能实现对球虫病的可持续控制。柔嫩艾美耳球虫转录组的特征描述可能会更好地了解寄生虫的生物学特性，并有助于开发更有效的球虫病控制方法。
从柔嫩艾美耳球虫第二代裂殖子全长 cDNA 文库中随机挑选的克隆的 5' 和 3' 末端生成了 15000 多个部分序列。对这些序列进行聚类产生了 1529 个独特的转录本（UT）。基于转录本组装，随后进行引物行走，成功生成了 433 个全长 cDNA 序列。这些序列的长度各不相同，范围从 441bp 到 3083bp，平均长度为 1647bp。简单序列重复（SSR）分析表明 CAG 是最丰富的三核苷酸基序，而密码子使用分析表明，柔嫩艾美耳球虫中使用频率最低的 10 个密码子是 UAU、UGU、GUA、CAU、AUA、CGA、UUA、CUA、CGU 和 AGU。随后对柔嫩艾美耳球虫完整编码序列的分析确定了 25 种假定的分泌蛋白和 60 种假定的表面蛋白，所有这些蛋白现在都是作为重组疫苗或药物靶点开发以控制禽球虫病的合理候选物。
本文描述了从柔嫩艾美耳球虫第二代裂殖子生成和特征描述全长 cDNA 序列，并提供了关于柔嫩艾美耳球虫转录组的新见解。生成的数据将有助于开发和验证球虫病的诊断和控制策略，并有助于柔嫩艾美耳球虫基因组序列的注释。
