Genomic organization, promoter activity of grass carp MDA5 and the association of its polymorphisms with susceptibility/resistance to grass carp reovirus.
Genomic organization, promoter activity of grass carp MDA5 and the association of its polymorphisms with susceptibility/resistance to grass carp reovirus.
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DOI：
10.1016/j.molimm.2012.01.012
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发表时间：
2012-04
影响因子：
3.6
通讯作者：
Lan-Ju Wang;Jianguo Su;Chunrong Yang;Q. Wan;Limin Peng
中科院分区：
文献类型：
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作者：
Lan-Ju Wang;Jianguo Su;Chunrong Yang;Q. Wan;Limin Peng
MDA5（黑色素瘤分化相关基因 5）是 RLR（视黄酸诱导基因 I 样受体）家族的成员，在针对病毒感染的先天免疫中发挥着关键作用。本研究阐明了草鱼（Ctenopharyngodon idella）MDA5（CiMDA5）基因序列的组织，并检测了其5′侧翼区的启动子活性。此外，还研究了单核苷酸多态性（SNP），以探讨其与草鱼呼肠孤病毒（GCRV）敏感性/抗性的关联。 CiMDA5基因组序列由10,906bp组成，包含7个外显子和6个内含子，这与具有多个外显子的对应序列不同。 CiMDA5 基因的 5' 侧翼区域包含几个假定的转录因子结合位点，使用基因组步移技术进行扩增，显示出启动子活性。在 CiMDA5 的完整序列中发现了 6 个 SNP。其中 5 个位于内含子，1 个位于 5' 侧翼区域。通过PCR-RFLP检测了易感和抗性鱼类的基因型和等位基因分布。结果表明-713 C/G和3338 A/C位点的基因型与GCRV抗性显着相关（P<0.05）。此外，在-713 C/G位点，未发现CC基因型个体； GG基因型组死亡率为42.65%，显着低于CG基因型组（73.91%）（P<0.05）。 3338 A/C位点CC基因型的死亡率（33.33%）显着低于AA和AC基因型（分别为61.54%、45.95%）（P<0.05）。数据表明-713 G和3338 C载体对GCRV具有抗性。这些结果为进一步研究GCRV抗性草鱼的选育提供了潜在的标记。
MDA5 (melanoma-differentiation-associated gene 5), a member of the RLR (retinoic acid-inducible gene I-like receptor) family, plays a pivotal role in innate immunity against viral infection. In the present study, the organization of grass carp (Ctenopharyngodon idella) MDA5 (CiMDA5) gene sequence was elucidated and promoter activity of its 5′-flanking region was detected. In addition, single nucleotide polymorphisms (SNPs) were investigated to explore their association with susceptibility/resistance to grass carp reovirus (GCRV). The CiMDA5 genomic sequence is composed of 10,906bp, containing seven exons and six introns, which is distinct from its counterparts with numbers of exons. The 5′-flanking region of CiMDA5 gene, containing several putative transcription factor binding sites, was amplified using genome walking technique, exhibiting promoter activity. Six SNPs were discovered in the complete sequence of CiMDA5. Five of them locate in introns and one in 5′-flanking region. The genotype and allele distribution were examined by PCR-RFLP in susceptible and resistant fish. The results indicate that genotypes at the −713 C/G and 3338 A/C loci were significantly associated with the resistance to GCRV (P<0.05). Furthermore, at −713 C/G site, no CC genotype individual was found; the mortality in GG genotype group was 42.65%, which was significantly lower than that in CG genotype group (73.91%) (P<0.05). The mortality in CC (33.33%) genotype at 3338 A/C locus was significantly lower than that in AA and AC genotype (61.54%, 45.95% respectively) (P<0.05). The data demonstrate that −713 G and 3338 C carrier are resistant to GCRV. These results provide potential markers for further investigation of selective breeding of resistant grass carp to GCRV.