Omar Mohamed A A, Li Meizhen, Liu Feiling, He Kang, Qasim Muhammad, Xiao Huamei, Jiang Mingxing, Li Fei
Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects/Institute of Insect Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Department of Plant Protection, Faculty of Agriculture (Saba Basha), Alexandria University, Alexandria 21531, Egypt.
Insects. 2020 Feb 12;11(2):121. doi: 10.3390/insects11020121.
The cotton mealybug, , is an invasive pest that can cause massive damage to many host plants of agricultural importance. is highly polyphagous, and shows extreme sexual dimorphism between males and females. The functions of DNA methyltransferase (DNMT) enzymes in the cotton mealybug have not been well studied. Here, we carried out an investigation of DNMTs in cotton mealybug to study their roles in sexual dimorphism. We found that the cotton mealybug has two copies of , but is absent. We then amplified the full-length cDNAs of (2,225 bp) and (2,862 bp) using rapid amplification cDNA ends (RACE). Quantitative reverse transcriptase PCR shows that both and are highly expressed in adult males, while the expression of is 30-fold higher in gravid females than in virgin females We knocked down and with small interfering RNAs (siRNAs), and both genes were successfully down-regulated after 24 h or 72 h in adult females and pupa (-test, < 0.05). Down-regulating the expression of these two genes led to offspring lethality and abnormal body color in adult females. Furthermore, the silencing of induced abnormal wing development in emerged adult males. Our results provide evidence that plays a crucial role in regulating sexual dimorphism in the cotton mealybug.
棉粉蚧是一种入侵性害虫，会对许多具有农业重要性的寄主植物造成巨大损害。棉粉蚧食性高度杂食，且雌雄之间表现出极端的性二态性。棉粉蚧中DNA甲基转移酶（DNMT）的功能尚未得到充分研究。在此，我们对棉粉蚧中的DNMT进行了研究，以探讨它们在性二态性中的作用。我们发现棉粉蚧有两个拷贝的[具体基因名称未给出]，但[另一个具体基因名称未给出]缺失。然后我们使用cDNA末端快速扩增（RACE）技术扩增了[具体基因名称未给出]（2225 bp）和[另一个具体基因名称未给出]（2862 bp）的全长cDNA。定量逆转录PCR显示，[具体基因名称未给出]和[另一个具体基因名称未给出]在成年雄性中均高度表达，而在妊娠雌性中[具体基因名称未给出]的表达比未交配雌性高30倍。我们用小干扰RNA（siRNA）敲低了[具体基因名称未给出]和[另一个具体基因名称未给出]，在成年雌性和蛹中处理24小时或72小时后，这两个基因均成功下调（t检验，P < 0.05）。下调这两个[具体基因名称未给出]基因的表达导致成年雌性后代致死和体色异常。此外，[具体基因名称未给出]的沉默导致羽化的成年雄性翅膀发育异常。我们的结果提供了证据，表明[具体基因名称未给出]在调节棉粉蚧的性二态性中起关键作用。
