title: Association analysis between SNPs in the 5'-flanking region of the chicken GRP78 gene, thermotolerance parameters, and tissue mRNA expression.
abstract: Glucose-regulated protein 78 (GRP78) is a molecular chaperone in the endoplasmic reticulum and can be induced by different kinds of environmental and physiological stress. Thus far, the role of the GRP78 gene in thermotolerance in chickens has not been investigated. In the present study, we detected sequence variations in the 5ꞌ-flanking region of the GRP78 gene and evaluated several thermotolerance parameters, such as T3, corticosterone, H/L ratio, and levels of CD3(+), CD4(+), and CD8(+) T cells, to further determine its associations at 35° and 15°C. The sequencing results revealed 10 SNPs in the 5'-flanking region of the GRP78 gene, and seven mutations were chosen for further genotyping in a White Recessive Rock (WRR) chicken population. The SNP C.-744C>G in WRR chickens was significantly correlated with heat tolerance parameters under both conditions; it may therefore exert a potential hereditary effect on heat tolerance, and the genotype GG may be advantageous for thermotolerance. The heart, liver, brain, and leg muscle tissues of 8-day-old WRR chickens were sampled from heat stress groups, which were defined by exposure to 1, 2, 3, and 6 h of persistent thermal stress, and a control group, which was not exposed to thermal stress. Quantitative real-time polymerase chain reaction assay indicated that the mRNA expression level of the GRP78 gene increased gradually under heat stress, peaked at 3 h, and then decreased. We conclude that the mRNA expression of the GRP78 gene is time- and tissue-dependent.
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
authors.forename: L N
authors.initials: LN
authors.lastname: Kong
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
authors.forename: D X
authors.initials: DX
authors.lastname: Zhang
authors.affiliation: Guangdong Wens Food Group Limited Company, Xinxing, Guangdong, China.
authors.forename: C L
authors.initials: CL
authors.lastname: Ji
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Zhang
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China qbluo@scau.edu.cn.
authors.forename: Q B
authors.initials: QB
authors.lastname: Luo
mesh_terms: D024506:5' Flanking Region; D000818:Animals; D000831:Animals, Newborn / Q000235:genetics / Q000254:growth & development; D002645:Chickens / Q000235:genetics / Q000254:growth & development*; D000091342:Endoplasmic Reticulum Chaperone BiP; D005260:Female; D005786:Gene Expression Regulation; D056726:Genetic Association Studies; D006360:Heat-Shock Proteins / Q000235:genetics*; D009928:Organ Specificity; D020641:Polymorphism, Single Nucleotide; D012333:RNA, Messenger / Q000032:analysis; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological; D013696:Temperature
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D012333:RNA, Messenger