Yu Yong-Man, Cho You-Hang, Youn Young-Nam, Quan Juan Hua, Choi In-Wook, Lee Young-Ha
Department of Applied Biology, College of Agriculture and Life Sciences, Chungnam National University, Daejeon, Korea.
Korean J Parasitol. 2012 Sep;50(3):243-7. doi: 10.3347/kjp.2012.50.3.243. Epub 2012 Aug 13.
Ascaris suum eggs are inactivated by composting conditions; however, it is difficult to find functional changes in heat-treated A. suum eggs. Here, unembryonated A. suum eggs were incubated at 20°C, 50°C, and 70°C in vitro, and the gene expression levels related to viability, such as eukaryotic translation initiation factor 4E (IF4E), phosphofructokinase 1 (PFK1), and thioredoxin 1 (TRX1), and to apoptosis, such as apoptosis-inducing factor 1 (AIF1) and cell death protein 6 (CDP6), were evaluated by real-time quantitative RT-PCR. No prominent morphological alterations were noted in the eggs at 20°C until day 10. In contrast, the eggs developed rapidly, and embryonated eggs and hatched larvae began to die, starting on day 2 at 50°C and day 1 at 70°C. At 20°C, IF4E, PFK1, and TRX1 mRNA expression was significantly increased from days 2-4; however, AIF1 and CDP6 mRNA expression was not changed significantly. IF4E, PFK1, and TRX1 mRNA expression was markedly decreased from day 2 at 50° and 70°C, whereas AIF1 and CDP6 mRNA expression was significantly increased. The expressions of HSP70 and HSP90 were detected for 9-10 days at 20°C, for 3-5 days at 50°C, and for 2 days at 70°C. Taken together, incremental heat increases were associated with the rapid development of A. suum eggs, decreased expression of genes related to viability, and earlier expression of apoptosis-related genes, and finally these changes of viability- and apoptosis-related genes of A. suum eggs were associated with survival of the eggs under temperature stress.
猪蛔虫卵在堆肥条件下会失活；然而，很难发现热处理后的猪蛔虫卵有功能变化。在此，将未受精的猪蛔虫卵在体外分别于20℃、50℃和70℃进行孵育，并通过实时定量逆转录聚合酶链反应评估与活力相关的基因表达水平，如真核翻译起始因子4E（IF4E）、磷酸果糖激酶1（PFK1）和硫氧还蛋白1（TRX1），以及与凋亡相关的基因表达水平，如凋亡诱导因子1（AIF1）和细胞死亡蛋白6（CDP6）。在20℃下直到第10天，未观察到虫卵有明显的形态改变。相比之下，虫卵发育迅速，受精虫卵和孵化出的幼虫开始死亡，在50℃时从第2天开始，在70℃时从第1天开始。在20℃时，IF4E、PFK1和TRX1的mRNA表达在第2 - 4天显著增加；然而，AIF1和CDP6的mRNA表达没有显著变化。在50℃和70℃时，IF4E、PFK1和TRX1的mRNA表达从第2天开始显著下降，而AIF1和CDP6的mRNA表达显著增加。在20℃下检测到HSP70和HSP90的表达持续9 - 10天，在50℃下持续3 - 5天，在70℃下持续2天。综上所述，温度的逐渐升高与猪蛔虫卵的快速发育、与活力相关基因的表达降低以及凋亡相关基因的早期表达有关，最终猪蛔虫卵活力和凋亡相关基因的这些变化与虫卵在温度胁迫下的存活有关。
