Hong Y H, Kim E-S, Lillehoj H S, Lillehoj E P, Song K-D
Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, USDA, Beltsville, MD 20705, USA.
Poult Sci. 2009 Mar;88(3):511-8. doi: 10.3382/ps.2008-00344.
Our previous genetic studies demonstrated that resistance to avian coccidiosis is linked with microsatellite markers LEI0071 and LEI0101 on chromosome 1. In this study, the associations between parameters of resistance to coccidiosis and single nucleotide polymorphisms (SNP) in 3 candidate genes located between LEI0071 and LEI0101 [zyxin, CD4, and tumor necrosis factor receptor super family 1A (TNFRSF1A)] were determined. The SNP were genotyped in 24 F(1) generation and 290 F(2) generation animals. No SNP were identified in the TNFRSF1A gene, whereas 10 were located in the zyxin gene and 4 in the CD4 gene. At various times following experimental infection of the F(2) generation with Eimeria maxima, BW, fecal oocyst shedding, and plasma levels of carotenoid, nitrite plus nitrate (NO(2)(-) + NO(3)(-)), and interferon-gamma (IFN-gamma) were measured as parameters of resistance. Single marker and haplotype-based tests were applied to determine the associations between the 14 SNP and the parameters of coccidiosis resistance. None of the CD4 SNP were correlated with disease resistance. However, by single marker association, several of the zyxin SNP were significantly associated with carotenoid or NO(2)(-) + NO(3)(-) concentrations. These were the SNP at nucleotide 149 associated with carotenoid at d 3 postinfection (PI), nucleotide 187 with carotenoid at d 6 and 9 PI, and nucleotide 159 with carotenoid between d 3 and 9 PI. In addition, the zyxin SNP at nucleotide 191 was significantly associated with increased levels of NO(2)(-) + NO(3)(-) at d 3 PI. By haplotype association, the zyxin SNP also were found to be highly associated with NO(2)(-) + NO(3)(-) at d 3 PI and increased IFN-gamma at d 6 PI. These results suggest that zyxin is a candidate gene potentially associated with increased resistance to experimental avian coccidiosis.
我们之前的遗传学研究表明，对禽球虫病的抗性与1号染色体上的微卫星标记LEI0071和LEI0101相关。在本研究中，测定了位于LEI0071和LEI0101之间的3个候选基因[斑联蛋白、CD4和肿瘤坏死因子受体超家族1A（TNFRSF1A）]中的单核苷酸多态性（SNP）与球虫病抗性参数之间的关联。对24只F1代和290只F2代动物进行了SNP基因分型。在TNFRSF1A基因中未鉴定出SNP，而在斑联蛋白基因中发现了10个，在CD4基因中发现了4个。在F2代动物经巨型艾美耳球虫实验感染后的不同时间，测量体重、粪便卵囊排出量以及类胡萝卜素、亚硝酸盐加硝酸盐（NO2- + NO3-）和干扰素-γ（IFN-γ）的血浆水平作为抗性参数。应用单标记和基于单倍型的检验来确定14个SNP与球虫病抗性参数之间的关联。CD4基因的SNP均与抗病性无关。然而，通过单标记关联分析，斑联蛋白基因的几个SNP与类胡萝卜素或NO2- + NO3-浓度显著相关。这些SNP分别是感染后第3天（PI）与类胡萝卜素相关的第149位核苷酸的SNP、感染后第6天和第9天与类胡萝卜素相关的第187位核苷酸的SNP，以及感染后第3天至第9天与类胡萝卜素相关的第159位核苷酸的SNP。此外，第191位核苷酸的斑联蛋白SNP与感染后第3天NO2- + NO3-水平升高显著相关。通过单倍型关联分析，还发现斑联蛋白基因的SNP与感染后第3天的NO2- + NO3-以及感染后第6天的IFN-γ升高高度相关。这些结果表明，斑联蛋白是一个可能与实验性禽球虫病抗性增强相关的候选基因。
