Miska K B, Schwarz R S, Jenkins M C, Rathinam T, Chapman H D
USDA/ARS, Animal Parasitic Diseases Laboratory, 10300 Baltimore Ave., Bldg. 1042 BARC-East, Beltsville, Maryland 20705, USA.
J Parasitol. 2010 Oct;96(5):982-6. doi: 10.1645/GE-2344.1. Epub 2010 Apr 29.
In order to determine the evolutionary relationships among Eimeria species that parasitize birds of the Galliformes, the 18s rDNA gene and a portion of the cytochrome oxidase subunit 1 (cox-1) were amplified from Eimeria species isolated from turkeys, chukars, and pheasants. The phylogenetic analysis of these sequences suggests that species infecting chickens are polyphyletic and, therefore, do not all share a direct common ancestor. Both the 18s rDNA and the cox-1 sequences indicate that Eimeria tenella and Eimeria necatrix are more closely related to Eimeria of turkeys and pheasants than to other species that infect the chicken. It is, therefore, likely that the chicken Eimeria spp. represent 2 separate ancestral colonizations of the gut, one of which comprises E. tenella and E. necatrix that infect the ceca, while the other includes Eimeria acervulina, Eimeria brunetti, Eimeria maxima, and Eimeria mitis, which infect the upper regions of the intestine.
为了确定寄生于鸡形目鸟类的艾美耳球虫物种之间的进化关系，从火鸡、石鸡和雉鸡分离出的艾美耳球虫物种中扩增了18s rDNA基因和细胞色素氧化酶亚基1（cox-1）的一部分。对这些序列的系统发育分析表明，感染鸡的物种是多系的，因此并非都有直接的共同祖先。18s rDNA和cox-1序列均表明，柔嫩艾美耳球虫和毒害艾美耳球虫与火鸡和雉鸡的艾美耳球虫的关系比与感染鸡的其他物种更为密切。因此，鸡艾美耳球虫物种可能代表肠道的2次独立的祖先定殖，其中一次包括感染盲肠的柔嫩艾美耳球虫和毒害艾美耳球虫，而另一次包括感染肠道上部区域的堆型艾美耳球虫、布氏艾美耳球虫、巨型艾美耳球虫和微小艾美耳球虫。
