Association analysis between SNPs in the 5'-flanking region of the chicken GRP78 gene, thermotolerance parameters, and tissue mRNA expression

Abstract

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 6111 Chicken GRP78 gene expression and thermotolerance ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (2): 6110-6123 (2015) 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.

Acquisition of thermotolerance in slow growing poultry: Elucidating through sequential mechanism of thermal conditioning during embryonic and early post-hatch period

“…Signi cant upregulation of Glucose regulated protein (GRP78) in intestinal tissue only observed in embryonic thermal conditioning group may be because of functional adaptations in terms of nutrient absorption at enterocyte level. Kong et al (2015) reported increased expression of GRP78 gene in different tissues with gradual exposure to heat stress in 8d old chicken due to tissue speci city of expression of this gene.…”

The Low Expression of DUSP1 and HSPA5 Inhibits Chicken Immune Response and Causes Decreased Immunity under Heat Stress

“…For example, GRP78 is required for cell proliferation and apoptosis inhibition of embryonic fibroblasts [19], and BiP / GRP78 plays a key role in avian reovirus-mediated apoptosis [20]. However, a rare study examining GRP78 response to heat stress (35 °C) showed that GRP78 mRNA levels in chicken heart, liver, brain, and leg muscles first increased (peaking at 3 h) and then decreased after, suggesting that the protein may function in avian immune response as well [21]. This study found that intracellular HSPA5 overexpression did not directly affect the differential expression of antigenpresenting genes, but did accelerate and enhance LPS recognition by HD11.…”