Shirley M W
Institute for Animal Health, Compton Laboratory, Nr Newbury, Berks, England.
Acta Vet Hung. 1997;45(3):331-47.
Many fundamental aspects of the biology of Eimeria spp. from the chicken remain poorly understood and some have not been investigated in detail for many years. New molecular tools are now available that could be used to underpin some of the more practical aspects of disease control. For example, a far better understanding of the epizootiology of the parasites, with precise knowledge of the characteristics of individual species and strains that are prevalent in the field might, in the future, be incorporated into strategies that see a more rational use of the available drugs and vaccines. The recent use of electrophoretic variation of enzymes to investigate parasite epizootiology is described and the general case for the development of specific, more sensitive DNA-based technologies is discussed. A wealth of DNA probes is potentially available from the large genome of Eimeria spp. and the genetic complexity of these parasites has recently been illustrated in more detail. In addition to a large nuclear genome comprising at least 14 linear chromosomes, studies on E. tenella have shown that, like Plasmodium and Toxoplasma, it also possesses a mitochondrial genome and a newly discovered "plant-like" genome that probably resides within an uncharacterised organelle and was acquired when an ancestor engulfed and kept and algal cell containing a chloroplast. A double-stranded RNA genome has also been identified in some species.
鸡艾美耳球虫生物学的许多基本方面仍未得到充分了解，有些方面已经多年未进行详细研究。现在有了新的分子工具，可用于支持疾病控制中一些更实际的方面。例如，对寄生虫的流行病学有更深入的了解，准确掌握田间流行的各个物种和菌株的特征，未来可能会纳入能更合理使用现有药物和疫苗的策略中。本文描述了最近利用酶的电泳变异来研究寄生虫流行病学的情况，并讨论了开发更特异、更灵敏的基于DNA技术的总体理由。艾美耳球虫的大基因组可能提供大量DNA探针，最近已更详细地阐明了这些寄生虫的遗传复杂性。除了包含至少14条线性染色体的大型核基因组外，对柔嫩艾美耳球虫的研究表明，它与疟原虫和弓形虫一样，也拥有线粒体基因组和新发现的“类植物”基因组，该基因组可能存在于一个未鉴定的细胞器中，是在其祖先吞噬并保留一个含有叶绿体的藻类细胞时获得的。在一些物种中还鉴定出了双链RNA基因组。
