温氏土鸡和白洛克鸡胚小肠EAATs mRNA表达差异及发育性变化

 【目的】研究温氏土鸡（WYFC）和隐性白洛克（WRRC）鸡胚小肠酸性氨基酸转运载体EAAT2（SLC1A2）和EAAT3（SLC1A1）mRNA的表达差异和发育性变化。【方法】选取蛋重相近的两品种纯系种蛋各96枚，每个品种随机分为6组，每组16枚，在相同的条件下进行孵化。分别就每个品种在9（E9）、12（E12）、14（E14）、17（E17）和19胚龄（E19）及出壳当天（DOH）选取16枚鸡胚，称重后采集小肠样品，采用real-time RT-PCR方法检测小肠EAATs mRNA的相对表达丰度。【结果】（1）9、12、14、17和19胚龄隐性白洛克胚蛋重量及出壳当天雏鸡体重极显著高于温氏土鸡（P＜0.01）；（2）从发育性变化来看，EAAT2 mRNA在两个品种表达基本一致，即E9—14表达量下调，E17有所上调，随后下调，E12、E17、E19和DOH两品种差异极显著（P＜0.01），E14差异显著（P＜0.05）；EAAT3 mRNA在两个品种都表现为随胚龄增加而表达上调，E19两品种差异极显著（P＜0.01），E12差异显著（P＜0.05）；（3）EAAT2和EAAT3 mRNA表达丰度，温氏土鸡鸡胚小肠高于隐性白洛克，不同发育阶段对其都有影响，均存在“品种×胚龄”的互作效应。【结论】EAATs mRNA表达丰度在品种和胚龄间存在差异，不同基因表达的发育模式亦不相同。

Comparison of Difference and Ontogenetic Expression of EAATs mRNA in the Small Intestine of Broiler Chick Embryo

【Objective】The objective of this study was to compare the difference and ontogenetic expression of glutamate transporters (EAAT2 and EAAT3) mRNA in small intestine of broiler chick embryo. Two breeds were selected, one was Wens Yellow-Feathered Chicken (WYFC, a Chinese local breed which grows slowly and marketed age for female is over 100 days) and the other was White Recessive Rocks Chicken (WRRC). 【Method】 Ninety-six fertilized eggs of each breed which had a similar weight were assigned into 6 groups for hatching. Sixteen small intestinal samples from each group were collected on embryonic days 9 (E9), 12 (E12), 14 (E14), 17 (E17), 19 (E19) and day of hatch (DOH) after the eggs were weighed. The expressions of EAATs mRNA were determined using real-time RT-PCR by relative quantification method. 【Result】The resuts showed that weight of embryonated egg on E9, E12, E14, E17 and E19, and hatchling of WRRC was significantly higher than that of WYFC (P＜0.01). Ontogenetic patterns of EAAT2 mRNA were similar in the 2 breeds，which downregulated from E9 to E14 and upregulated on E17, followed by an downregulation to DOH. In comparison between the two breeds, there was a highly significant difference (P＜0.01) on E12, E17, E19 and DOH and a significant difference (P＜0.05) on E14. Ontogenetic patterns of EAAT3 mRNA were upregulated along with embryonic development in both 2 breeds, which showed a highly significant difference (P＜0.01) on E19 and a significant difference (P＜0.05) on E12. The abundance of EAAT2 and EAAT3 mRNA in the small intestine of WYFC was higher than that of WRRC and affected by embryonic days. There was an interaction of breed×embryonic day on the both EAAT2 and EAAT3 mRNA abundance. 【Conclusion】 The expression of EAATs mRNA differed in breeds as well as embryonic days. Ontogenetic patterns of EAAT2 and EAAT3 mRNA were different.