温度对荒漠昆虫小胸鳖甲幼虫肌动蛋白基因表达的影响

Effect of Temperature on the Expression of β-actin Gene in the Desert Insect Microdera punctipennis (Coleoptera:Tenebriodae) Larvae

【目的】肌动蛋白β-actin是应用实时荧光定量PCR检测基因表达的常用内参基因,测定和分析荒漠昆虫小胸鳖甲幼虫中β-actin基因表达的稳定性,判断其是否可作为内参基因。【方法】选取不同龄期的小胸鳖甲幼虫经过42、5、10和15℃处理不同时间后,利用实时荧光定量PCR检测β-actin基因的表达,以基因绝对拷贝数的对数进行单因素方差分析。【结果】小胸鳖甲幼虫在不同龄期β-actin的表达有显著差异;1龄幼虫在不同温度处理后,β-actin的表达都有显著升高;4龄幼虫在不同温度处理后β-actin的表达基本上没有变化;7龄幼虫在10、15和42℃条件下β-actin的表达都显著升高,但5℃处理没有影响。【结论】小胸鳖甲幼虫的β-actin基因具有发育阶段性差异性表达特点,温度对不同龄期幼虫的β-actin基因表达的影响不同,β-actin基因可能不适合在小胸鳖甲幼虫基因表达分析中作为内参基因。

【Objective】β-actin gene is commonly used as a reference gene in real time fluorescence quantitative PCR（qRT-PCR） for assaying gene expression. The present study aims at evaluating if β-actin gene is appropriate for being used as a reference gene in the larvae of Microdera punctipenis through analysis of the expression stability of β-actin gene under different temperatures. 【Method】M. punctipenis larvae of different instars were treated at 42℃,5℃,10℃,15℃ respectively for various hours,and the expression of β-actin gene was then determined by qRT-PCR. The data were converted to the logarithm of the absolute copies of the gene,and then statistically analyzed with one way ANOVA. 【Result】The results showed a significant difference in the expression level of β-actin gene in M. punctipennis larvae from the 1st to the 7th instars.The expression of β-actin gene in the 1st instar after being treated at different temperatures was significantly increased. However,there was no significant change in the expression of β-actin gene in the 4th instar after temperature treatment. For the 7th instar the expression of β-actin gene was up-regulated after the larvae were treated at 10℃,15℃,and 42℃ respectively,but 5℃ had no influence in the gene expression. 【Con-clusion】The expression of β-actin gene in M. punctipenis larvae was developmentally differential. The influence of temperature in the expression of β-actin gene in M. punctipenis larvae varies. β-actin gene may not to be used as an appropriate reference gene in the gene expression analysis in M. punctipenis larvae.