College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, P. R. China.
Poult Sci. 2009 Dec;88(12):2549-54. doi: 10.3382/ps.2009-00404.
This study was to investigate the expression trait of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) gene and the effect of cold stress on the mRNA levels of PPAR-gamma in spleen, thymus, and bursa of Fabricius of chickens. Eighty-four 1-d-old male chickens were randomly allocated to 12 groups (7 chickens per group). There was 1 control group and 5 treatment groups for acute cold stress and 3 control groups and 3 treatment groups for chronic cold stress. Chickens were maintained in our animal facility, kept under a 16L:8D cycle and temperature (30 +/- 2 degrees C), and given free access to standard chow and water. The cold stress was initiated when the birds were 15 d of age, with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 d, respectively. Cold stress temperature was 12 +/- 1 degrees C. Spleen, thymus, and bursa of Fabricius were collected for the assessment of the mRNA levels by real-time PCR after stress termination. The results showed that the PPAR-gamma gene is expressed in spleen, thymus, and bursa of Fabricius, and its expression level is different in different tissues and at different ages. Acute cold stress significantly decreased (P < 0.05) the mRNA levels of the PPAR-gamma gene of spleen and thymus in all treatment groups and significantly increased (P < 0.05) the mRNA levels of the PPAR-gamma gene of bursa of Fabricius in all treatment groups. Compared with the corresponding control groups, chronic cold stress resulted in a significant increase (P < 0.05) of the mRNA levels of the PPAR-gamma gene in spleen and a significant decrease (P < 0.05) of the mRNA levels of the PPAR-gamma gene in thymus and bursa of Fabricius. The results indicate that the PPAR-gamma gene is expressed in all 3 immune organs and has different expression traits. The magnitude and direction of change in PPAR-gamma gene expression differs with the type of cold stress applied and also varies by tissue.
本研究旨在探讨过氧化物酶体增殖物激活受体-γ（PPAR-γ）基因的表达特征，以及冷应激对鸡脾脏、胸腺和法氏囊 PPAR-γ mRNA 水平的影响。将 84 只 1 日龄雄性鸡随机分为 12 组（每组 7 只鸡）。其中 1 个对照组和 5 个急性冷应激处理组，3 个对照组和 3 个慢性冷应激处理组。鸡在我们的动物设施中饲养，保持 16L:8D 光照周期和温度（30±2℃），并自由获得标准饲料和水。在鸡 15 日龄时开始冷应激，急性冷应激持续 1、3、6、12 和 24 小时，慢性冷应激持续 5、10 和 20 天，冷应激温度为 12±1℃。应激结束后，采集脾脏、胸腺和法氏囊，通过实时 PCR 评估 mRNA 水平。结果表明，PPAR-γ 基因在脾脏、胸腺和法氏囊中表达，其表达水平在不同组织和不同年龄时存在差异。急性冷应激显著降低（P<0.05）所有处理组的脾脏和胸腺 PPAR-γ 基因的 mRNA 水平，显著增加（P<0.05）所有处理组的法氏囊 PPAR-γ 基因的 mRNA 水平。与相应的对照组相比，慢性冷应激导致脾脏 PPAR-γ 基因的 mRNA 水平显著升高（P<0.05），胸腺和法氏囊 PPAR-γ 基因的 mRNA 水平显著降低（P<0.05）。结果表明，PPAR-γ 基因在所有 3 个免疫器官中表达，具有不同的表达特征。PPAR-γ 基因表达的变化幅度和方向因冷应激类型的不同而不同，也因组织而异。
