Control of porcine reproductive and respiratory syndrome (PRRS) through genetic improvements in disease resistance and tolerance.
Control of porcine reproductive and respiratory syndrome (PRRS) through genetic improvements in disease resistance and tolerance.
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DOI：
10.3389/fgene.2012.00260
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发表时间：
2012
影响因子：
3.7
通讯作者：
Dekkers J
中科院分区：
文献类型：
--
作者：
Rowland RR;Lunney J;Dekkers J
由猪繁殖与呼吸综合征病毒（PRRSV）引起的感染对北美、欧洲和亚洲的猪生产具有严重的经济影响。PRRS在1990年代的出现和最终占主导地位可能是1970年代后期开始的猪肉行业变革的结果，这使得该病毒在现代商业生产系统中占据了独特的位置。PRRSV感染可导致严重的临床疾病，但可维持终生的亚临床感染，并参与多种微生物综合征。目前的疫苗减轻了临床症状，但对疾病控制和消除的作用有限。疫苗接种后保护性免疫力相对较差是病毒产生大量遗传多样性的能力的函数，结合了逃避先天性和适应性免疫应答的几种策略。2007年，建立了PRRS宿主遗传学联盟（PHGC），以探索宿主遗传学作为PRRS控制途径的作用。PRRS的PHGC模型结合了大量生长猪的实验感染，并创造了在群体水平上研究实验性PRRSV感染的机会。结果表明，猪可以被分为不同的表型组，包括显示抗性的猪（即，低病毒载量）或对感染表现出“耐受性”的猪。耐受性通过在面对相对高的病毒负荷时正常增重的猪来说明。全基因组关联分析已经鉴定了4号染色体（SSC 4）上与抗性相关的区域;即，在感染的最初42天内累积病毒载量较低。基因组区域靠近参与先天免疫的基因家族。该区域还与受攻击猪的更高体重增加相关，表明具有抗性等位基因的猪似乎不会同时经历生长减少，即，抵抗力和耐受力并不是对立的这些结果为开发育种计划创造了机会，这些育种计划将产生对PRRS具有更高抗性的猪，同时具有高生长率。参与实际耐受性的基因组标记的鉴定可能会证明更加困难，主要是因为耐受性难以量化，并且因为耐受性机制仍然知之甚少。另一种研究途径包括鉴定与疫苗接种后改善应答相关的基因组标记。
Infections caused by porcine reproductive and respiratory syndrome virus (PRRSV) have a severe economic impact on pig production in North America, Europe, and Asia. The emergence and eventual predominance of PRRS in the 1990s are the likely result of changes in the pork industry initiated in the late 1970s, which allowed the virus to occupy a unique niche within a modern commercial production system. PRRSV infection is responsible for severe clinical disease, but can maintain a life-long subclinical infection, as well as participate in several polymicrobial syndromes. Current vaccines lessen clinical signs, but are of limited use for disease control and elimination. The relatively poor protective immunity following vaccination is a function of the virus's capacity to generate a large degree of genetic diversity, combined with several strategies to evade innate and adaptive immune responses. In 2007, the PRRS Host Genetics consortium (PHGC) was established to explore the role of host genetics as an avenue for PRRS control. The PHGC model for PRRS incorporates the experimental infection of large numbers of growing pigs and has created the opportunity to study experimental PRRSV infection at the population level. The results show that pigs can be placed into distinct phenotypic groups, including pigs that show resistance (i.e., low virus load) or pigs that exhibit “tolerance” to infection. Tolerance was illustrated by pigs that gain weight normally in the face of a relatively high virus load. Genome-wide association analysis has identified a region on chromosome 4 (SSC4) correlated with resistance; i.e., lower cumulative virus load within the first 42 days of infection. The genomic region is near a family of genes involved in innate immunity. The region is also associated with higher weight gain in challenged pigs, suggesting that pigs with the resistance alleles don't seem to simultaneously experience reduction in growth, i.e., that resistance and tolerance are not antagonistically related. These results create the opportunity to develop breeding programs that will produce pigs with increased resistance to PRRS and simultaneously high growth rate. The identification of genomic markers involved in actual tolerance will likely prove more difficult, primarily because tolerance is difficult to quantify and because tolerance mechanism are still poorly understood. Another avenue of study includes the identification of genomic markers related to improved response following vaccination.
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影响因子：
5
作者：
Rowland RR
通讯作者：
Rowland RR
影响因子：
3.3
作者：
Rowland RR;Lawson S;Rossow K;Benfield DA
通讯作者：
Benfield DA
影响因子：
1.5
作者：
BENFIELD, DA;NELSON, E;CHLADEK, D
通讯作者：
CHLADEK, D
影响因子：
2.6
作者：
Karniychuk UU;Geldhof M;Vanhee M;Van Doorsselaere J;Saveleva TA;Nauwynck HJ
通讯作者：
Nauwynck HJ
DOI：
10.2460/javma.2005.226.1707
发表时间：
2005-05-15
影响因子：
1.9
作者：
Lowe, JF;Husmann, R;Goldberg, TL
通讯作者：
Goldberg, TL