State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Arch Insect Biochem Physiol. 2020 Sep;105(1):e21721. doi: 10.1002/arch.21721. Epub 2020 Jun 17.
The alligator weed flea beetle, Agasicles hygrophila is a monophagous natural enemy of the invasive alligator weed Alternanthera philoxeroides. Oogenesis plays a vital role in the process of individual development and population continuation of oviparous insects. Sox is an ancient and ubiquitous metazoan gene family that plays a key regulatory role in various physiological processes, including oogenesis, which is closely related to fecundity. In this study, two Sox genes AhDichaete and AhSox3 were cloned and characterized, and then the expression profiles of AhDichaete and AhSox3 were qualified by a quantitative reverse transcription-polymerase chain reaction. The result showed that these two Sox genes were expressed significantly higher in ovary, especially in the adult developmental stage. Furthermore, the functions of AhDichaete and AhSox3 in A. hygrophila females were studied using RNA interference (RNAi). Fewer offsprings were produced when AhDichaete and AhSox3 RNAi females mated with wild-type males. Moreover, dsAhSox3 injection reduced the hatching rate of eggs but injection with dsAhDichaete did not. Further study of the reproductive system of AhDichaete and AhSox3 RNAi females showed that yolk protein deposition reduction in the ovarioles, then the expression of vitellogenin gene AhVg2 in ovaries was decreased. These results indicate that AhDichaete and AhSox3 play an important regulatory role in the process of ovarian development and oogenesis by affecting yolk synthesis in the ovary of A. hygrophila.
喜旱莲子草叶甲，Agasicles hygrophila，是入侵性喜旱莲子草 Alternanthera philoxeroides 的单食性天敌。卵子发生在卵生昆虫个体发育和种群延续过程中起着至关重要的作用。Sox 是一个古老而普遍存在的后生动物基因家族，在包括卵子发生在内的各种生理过程中发挥着关键的调节作用，而卵子发生与生殖力密切相关。在本研究中，克隆并鉴定了两个 Sox 基因 AhDichaete 和 AhSox3，然后通过定量逆转录聚合酶链反应（qRT-PCR）鉴定了 AhDichaete 和 AhSox3 的表达谱。结果表明，这两个 Sox 基因在卵巢中表达水平较高，尤其是在成虫发育阶段。此外，还通过 RNA 干扰（RNAi）研究了 AhDichaete 和 AhSox3 在喜旱莲子草叶甲雌虫中的功能。当 AhDichaete 和 AhSox3 RNAi 雌虫与野生型雄虫交配时，后代数量减少。此外，dsAhSox3 的注射降低了卵的孵化率，但 dsAhDichaete 的注射没有。对 AhDichaete 和 AhSox3 RNAi 雌虫生殖系统的进一步研究表明，卵原细胞中卵黄蛋白沉积减少，随后卵巢中 vitellogenin 基因 AhVg2 的表达降低。这些结果表明，AhDichaete 和 AhSox3 通过影响卵巢中卵黄的合成，在喜旱莲子草叶甲卵巢发育和卵子发生过程中发挥重要的调节作用。
